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FLYING MICRO-ROBOTS

Inspired by dragonflies, p31 MULTIPHYSICS SIMULATION It’s looking more like CAD, p39 XMAS GADGET FREAK Retractable icicle lights, p60

DECEMBER 2009 $15.00

ACCELERATING ENGINEERING INNOVATION

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Plus NEW HYDRAULIC SYSTEMS POISED FOR FLIGHT, p48

Inside the High Stakes Biz of Drying Pasta, p40


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Two new C-more 6-inch operator touch panels offer: • Clear TFT 65K color display • LED backlight • Lower price!

With these new C-more 6-inch TFT touch panels, we’ve improved features and lowered the cost. Check out the powerful yet easy-to-use configuration software by downloading a demo version at: http://support.automationdirect.com/demos.html ALL C-MORE PANELS INCLUDE: • Analog resistive touch screen with unlimited touch areas • One USB A-type and one USB B-type port • Serial communications interface FULL-FEATURED MODELS ADD: • 10/100Base-T Ethernet communications • CompactFlash slot for data logging REMOTE ACCESS AND CONTROL BUILT-IN No Additional Hardware required The C-more Remote Access feature resides in all panels with Ethernet support, and requires no option modules. Access real-time data or initiate an action on a control system from anywhere, any time. (Requires software and firmware

CONNECT TO CONTROLLERS WITH DRIVERS FOR: • All AutomationDirect PLCs/PACs • Allen-Bradley ControlLogix® CompactLogix® MicroLogix™ 1100/1400 Ethernet ENI Adapter for SLC Series FlexLogix SLC® 5/05 Ethernet™ MicroLogix™

• Modbus RTU and TCP/IP Ethernet • GE 90/30 SNPX (90/30, 90/70. Micro90, VersaMax Micro) • Omron Host Link Adapter (C200/C500), FINS Serial and Ethernet • Selected Mitsubishi FX Series, Q Series • Siemens S7-200 PPI and S7-200/300 Ethernet (ISO over TCP/IP) www.automationdirect.com For complete information or to order our free catalog, visit: www.automationdirect.com/c-more

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NANO SUPER AIR NOZZLE FOR PRECISION BLOWOFF

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The Nano Super Air Nozzle is the smallest available. EXAIR’s “precision blowoff ” provides optimum air entrainment for a directed high volume, high velocity airflow. The compact size permits mounting where space is limited.

Safety Air Guns use engineered Air Nozzles to provide superior performance. Safe operation is assured along with low air consumption and noise level. Many styles and nozzles are offered. Extensions and Stay Set Hoses are available.

Many blowoff, cleaning, cooling and drying applications require high force and extensive reach. EXAIR’s Super Air Nozzle Clusters deliver up to 9.8 lbs of force. Three sizes for handheld and stationary mounting are available.

Exair Corporation www.airnozzle.info/14/nano.htm

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UNIQUE FLAT NOZZLE USES PATENTED TECHNOLOGY The 2” Super Air Nozzle is a highly efficient, unique flat air nozzle. Using EXAIR’s patented technology, a precise amount of air is released through the thin slot, across a flat surface. The result is a wide, forceful stream of high velocity, laminar airflow. Force and flow can be easily adjusted. Exair Corporation www.airnozzle.info/14/2san.htm

DIRECTED BLAST OF AIR EXAIR Air Jets utilize the coanda effect (wall attachment of a high velocity fluid) to produce a vacuum on one end that pulls large volumes of room air through the unit. Both the outlet and inlet can be ducted for remote positioning. Exair Corporation www.airnozzle.info/14/jet.htm

SUPER AIR NOZZLES™ The aerodynamic design of EXAIR’s Super Air Nozzles provide a high thrust, concentrated stream of high velocity airflow. The sound level is as low as 71 dBA with hard- hitting force up to 23 pounds. All meet OSHA noise and pressure requirements. Exair Corporation www.airnozzle.info/14/super.htm

A BREEZE TO A BLAST These Safety Air Nozzles are adjustable, making them suitable for a wide variety of blowoff applications. EXAIR’s design allows you to “tune in” the force and flow to the application requirements, thereby minimizing air consumption. A micrometer like dial indicates the gap setting. Exair Corporation www.airnozzle.info/14/adjust.htm

This small Super Air Nozzle costs only $30. Installing it in place of one 1/4” copper tube can save you $592.80 per year.

Here’s how: A 1/4" copper tube is a common homemade blowoff off th that hat sure off consumes 33 SCFM when at a normal supply pressure 80 PSIG. EXAIR’s award winning Model 1100 Super Air Nozzle is 1/4 NPT and consumes only 14 SCFM at 80 PSIG. ozzle) = 19 SCFM 33 SCFM (copper tube) - 14 SCFM (Super Air Nozzle) ff is continuous. compressed air saved. For this example, the blowoff d cubic feet of compressed p Most large plants know their cost per 1000 standard air. If you don’t know your actual cost per 1000 SCF, 25¢ is a reasonable ble average to use.

SCFM saved x 60 minutes x cost/1000 SCF = Dollars saved ed per hour. In this case, 19 SCFM x 60 minutes x .25/1000 = 28.5 cents nts per hour. hou ur. 28.5 cents per hour x 40 hour work week = $11.40 per week. eek.. eek $11.40 per week x 52 weeks = $592.80 per year. eks. ks. The Super Air Nozzle pays for itself in just over two weeks.

For more information, visit www.exair.com/14/410.htm 14/4 410 10.htm If you would like to discuss an application, contact an Application Engineer at:


How do we turn more ideas into successful products?

The Siemens answer: PLM Software to build the right product — and build the product right. Escalating costs. Tighter schedules. Increased complexity. The challenge of turning more ideas into successful products has never been greater. You need a product lifecycle management solution that improves everything from design to manufacturing – and beyond. Find out how Siemens PLM Software can help your company stand out, no matter how tough the challenge. www.siemens.com/plm/answers.

Answers for Industry. © 2009 Siemens Product Lifecycle Management Software Inc. All rights reserved. Siemens and the Siemens logo are registered trademarks of Siemens AG. All other logos, trademarks or service marks used herein are the property of their respective owners.


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Gadget Freak®

Check Out Our New Blogs …

Calling all backyard inventors — check out our Gadget Freak files for profiles of past and present Gadget Freaks, watch videos and submit your own project. www.designnews.com/gadgetfreak

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Steve Ravet explains why MBED is the musthave tool for the non-embedded developer. http://designnews.hotims.com/23129-503

Sign up and get headlines delivered right to your desktop as soon as they’re published. http://www.designnews.com/rss/

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Supplements Go to www.designnews.com/archive to view our technology-specific supplements.

The Weird and Wonderful World of Wireless Wireless Guru Joel Young on the best way to connect an iPod into your car’s audio system. http://designnews.hotims.com/23129-505

Gearo Wolfe The driver of a beat-up cement mixer has big, no huge, problems on the road. http://designnews.hotims. com/23129-506

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Pilot John Loughmiller on the downside of modern instrument panels — and more. http://designnews.hotims.com/23129-502

Why aren’t consumers stampeding EV dealerships? http://designnews.hotims. com/23129-504

WEBCASTS BLOGS PODCASTS

Webcast: State-of-the-Art Materials for Rapid Prototyping Learn about the latest advancements in materials used in rapid prototyping processes as technical experts discuss the latest material formulations and state-of-the-art applications. Design engineers also will gain a better understanding of the properties and performance characteristics of some of the newest materials and material combinations available, specific design considerations, and tips and tricks for designing for rapid prototyping. http://designnews.hotims.com/23129-507

2010 GOLDEN MOUSETRAP AWARDS Don’t miss out on the biggest product contest of the year! Enter the most spectacular product or tool for design engineers your company designed in the past year and it could be featured in our special Golden Mousetrap Awards issue in April 2010. Deadline for entries is coming up fast — Jan. 15, 2010, so get your entry in today! Go to www.designnews.com/ mousetrap for an entry form and full contest details.

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Product Literature PEEK Metric Screws from Net Motion PEEK fasteners have advantages over stainless steel: about 20 percent the weight, dielectric properties, corrosion-proof, low thermal conductivity and anti-magnetic. Used in consumer electronics, medical equipment, chemical and fluid processing, aerospace and automotive industries, they offer one of the best price/performance profiles. http://designnews.hotims.com/23129-508

White Paper Improve 3-D CAD Productivity from PTC There are two mainstream, accepted approaches to 3-D design: parametric and explicit. Each approach is different and each offers its own benefits and applications. The trick is determining which is right for your company. This paper highlights the parametric, explicit and hybrid approaches and their differences. http://designnews.hotims.com/23129-509

Research Study From Robert Bosch: Are Motor Manufacturers Satisfying Engineers’ Criteria? In August, a study was conducted among design engineers to learn more about their usage of and satisfaction with the motors they incorporate into their designs. The study also examines how the motors they use or have used in the past measure up in comparison with their design requirements. http://designnews.hotims.com/23129-510

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Š2008 Moog. All rights reserved.

IT’S TIME TO CHANGE THE FUTURE OF MOTION CONTROL.

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THE

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Looking for Better Mousetrap Builders! Design News’ 2009 Golden Mousetrap Winners and Finalists Be sure to check out the companies who made the cut in 2009 at http://www.designnews.com/channel/Golden_ Mousetrap_Winners.php. And take a look at those who gave our winners a run for their money: http://www.designnews.com/channel/Golden_ Mousetrap_Finalists.php.

IN THIS ISSUE WE HAVE AN AMAZING

article by Senior Editor Chuck Murray about Larry Miller, an inventor who overcame enormous technical obstacles, funding problems, and outright institutional resistance to create a life-saving device. Today, it’s used by emergency personnel to administer fluids through the bones of patients who have lost significant amounts of blood. I found Larry’s story particularly compelling because it showcases the degree of technical expertise, creativity, and dogged perseverance that all great engineers possess and, frankly, require to get a new product to market — whether you are designing products that save lives or products that simply make someone’s life easier. It’s the latter type of product that we have been recognizing for the past seven years through our annual Design News Golden Mousetrap Awards, which showcase some of the best and most innovative technologies and tools that help design engineers do their jobs better and faster. In fact, I am extraordinarily proud of the efforts of the Design News team and the companies that have supported this program and the work they’ve put in to improve and expand it each and every year. Since we introduced the program in 2003, we’ve recognized the achievements of literally hundreds of engineers and developers who have created everything from leadingedge motion control systems to sophisticated electronic components to the latest software tools for engineers. The stories behind the development of these products and the designs themselves are always compelling, sometimes quite entertaining, which is one big reason our editorial team especially looks forward to reviewing the entries, which continue to increase in number each year. So, frankly, I am delighted to announce that we’ve moved the 2010 Golden Mousetrap Awards timetable ahead by a few months. The call for entries is now open

and we will be accepting submissions through Jan. 15, 2010 (better hurry!). All finalists and winning entries will be announced in our April 2010 issue and on our website, giving the award winners more time to promote their victory in the same calendar year they’ve received the accolades. Plus, winners will be getting a very cool plaque — complete with 3-D mousetrap — suitable for hanging in a place of honor in their company lobby. This year Golden Mousetrap Awards will be given in four major categories: Design Tools; Electronics; Materials/Fastening, Joining and Assembly; Motion Control/Automation, plus 20 sub-categories. Entries will be judged on the significance of the product to design engineers, the uniqueness of the design, and the creativity and innovation applied in the design effort. So, please, don’t wait to tell us about the spectacular new products your company has designed in the past year and the chance to get your engineering team some great recognition. You can get all the details — including the entry form, full contest rules, a list of previous winners and an FAQ — at www.designnews.com/mousetrap. This year, we’ve even added information on how former winners have effectively promoted their winning status. Read the article, for example, that Lori Appel, manager, Marketing Communications at Custom Sensors & Technologies and Kavlico, wrote on a finalist in this year’s Golden Mousetrap Awards and promoted in a company E-Newsletter. It generated the highest number of clicks in that installment of the E-Newsletter. Have questions? Our capable Executive Editor Liz Taurasi is heading up the 2010 Golden Mousetrap Awards so please feel free to ping her at elizabeth.taurasi@reedbusiness.com. Karen Field, Editor-in-Chief kfield@reedbusiness.com

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Made by Monkeys designnews.com/ »madebymonkeys

I Think I Feel an EMF Headache Coming on! I am agog at the number of websites springing up, like Toolsforwellness.com, offering a plethora of products to protect one against the common symptoms of EMF exposure, including headaches, fatigue, nausea and overall lack of energy. The jewelry is quite stylish, I must say! Feeling a little tired and a headache coming on, I thought I would consult Daryl Gerke, an EMI expert and co-owner of the consulting firm Kimmel Gerke Assoc., which specializes in Electromagnetic Interference and Compatibility, before I rushed online to order my own personal protection device. Since he’s been consulting on EMI issues for the past three decades, I figured he’d be the first one to drape himself with these products if they do indeed have any therapeutic benefit. He explained that concern over EMF issues dates back 20 or 30 years, when researchers did one of the first epidemiological studies on the impact of 60 Hz power lines on cancer rates. Nothing was ever proven, though, and Gerke says he believes that one study even suggested you might actually live slightly longer if you were born and raised under a power line! Some years ago Gerke ran into a fellow engineer who was doing consulting for the Electric Power Research Institute. He had become a kind-of clearing house for information on the topic. “So I said to him, ‘Okay I’m being asked about this stuff all the time, is it or is it not a problem?’” says Gerke. “He told me, ‘We’re spending millions of dollars to research this, and we’ve seen nothing that suggests there is any correlation.’” As for the emissions from cell phones, computers and other electronic devices, Gerke says he’s seen nothing to suggest that there is any direct cause/effect relationship. Further, he says, the FCC and OSHA have established safe levels of EMI fields, and these levels are basically well beyond what most of us are exposed to. “Maybe if you’re standing next to the antenna on a high-powered radio transmitter or climbing on the tower you could get in that range, but most of us never see those levels. The emissions that you get from a computer are millions, maybe even billions times lower than what you would get near a radio transmitter. And even there, the main concern is the cumulative effect,” he says. Gerke has done measurements for the Forest Service after concern was raised over the possibility that workers at a fire watch tower with antennas on the roof could be frying their brains up there. “It was actually kind of a fun project,” says Gerke. “We went and waved the magic wand and — nothing. There wasn’t enough power.” At this point, the idea that an EMF protection bracelet would get rid of my headache was beginning to sound more and more unlikely. And then, Gerke delivered his final verdict: “I am an engineer, and in spite of all the scientific studies, no threat has been proven. And even if there were a threat, I don’t think this kind of jewelry is a solution,” he says. “Some of the terms used to market this stuff, like ‘Diode Jewelry for EMF Protection,’ are just amazing. In fact, if you think about it, diodes would probably aggravate the problem since they kind-of splatter energy all over the place.” In the end, Gerke says he thinks the biggest threat these devices pose is to — Ding! Ding! Ding! — other devices. “And as far as fields go,” he says, “the one I worry about more than anything is the gravitational field. Jump off a bridge or a building and it will suck you right down to the ground.” If you’ve had a run-in with a product that failed to live up to your expectations, we’d like to hear about it. E-mail your examples to kfield@reedbusiness.com.


SolidWorks is a registered trademark of Dassault Systèmes. ©2009 Dassault Systèmes. All rights reserved.

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MAIL Readers Sound Off TESLA’S PERFORMANCE SPEAKS FOR ITSELF

Good call on honoring Tesla engineer JB Straubel, “Tesla Engineer Boosts EV Range to New Heights,” (DN 09.09, http://designnews.hotims.com/23129511). The Tesla is expensive but it only takes one ride, one 0-60, sub-four-second acceleration, to show that this car is in the top tier of high-performance automobiles and could be considered a bargain compared to a $400,000 Porsche Carrera GT. You won’t buy a Tesla using the cost-benefit analysis one does when buying a Honda Accord. Now, the analysis for paying $40K for an electric Chevy is another matter. Kevin Fullerton Litchfield Park, AZ EVS ARE NOT READY FOR PRIME TIME

From your response to the e-mail, “Was the Tesla Story ‘a Joke?’” (DN 11.09, http://designnews.hotims.com/23129512), I agree with your assessment of electric cars not being ready for prime time. I think there is another big issue besides the battery technology, infrastructure. How many businesses have electric outlets in the parking lots? The only ones I know about are in Alaska.

What about all the people who live in apartments? I don’t think the neighbors would like electric cords running all over the parking lots. And what do you do if you want to visit grandma who lives 300 miles away? It takes two days to get there because you have to stop for four to six hours to recharge and you need an outlet to plug into. And what if I forget to plug in every night? I can’t get to work the next day until I recharge. I believe most people would still need or want to keep a gasoline vehicle. These are not impossible issues to solve, but we are not there yet. In the meantime, the hybrids seem to be an adequate intermediate step. I like what I have read about the hydraulic hybrids. Although the applications are geared toward intercity trucks, two to three times the gas mileage sounds pretty good, even if it is diesel. And with the high start-off hp, we can satisfy Americans’ desire for big pickup trucks and SUVs for hauling boats and trailers. And you can still get to grandma’s house in one day. By the way, I would love to have a Tesla Roadster. Zero to 60 in four to five seconds, sounds like fun. I just can’t figure out how to get the whole family into it for the drive to grandma’s for Thanksgiving. Marc L. Howell Huntsville, AL TESLA STORY WAS A JOKE

The real “joke” in the current Design News article is the underlying presumption that carbon dioxide is a danger! Sure, CO2 is a greenhouse gas, but constitutes but .0365 percent of total atmospheric gases! But, 99 percent, diatomic nitrogen and oxygen, are not. 12

D E S I G N N E W S D E C E M B E R 2 0 0 9 [ w w w. d e s i g n n e w s . c o m ]

Blaming CO2 generation as a cause of a future calamity is like assuming that a little smudge on your window will affect your home temperatures! CO2 is a basis for human existence and attendant growth! Where does one think hydrocarbon fuels come from? In large part over billions of years of CO2 conversion to plant life by the sun. Market forces, free from government pressures, will determine what is truly “green.” If it is savings you want, do not be led down the path of suspending ones judgment and accepting arbitrary mandates. Herbert Heller Pittsburgh, PA TESLA’S RESULTS HAVE BEEN IMPRESSIVE

I would point out that Tesla is profitable now which is more then you can say for most auto companies. Developing a new technology, building a company, a factory and getting a new car approved by the government is a huge investment. You can’t take the up front investment and divide it by the first six months of production and say that is the cost per car. I think Tesla is up to around 800 cars now, actually, with most of them produced in the last nine months. Pretty good for a high-end sports car at a point where the car market has crashed. As to the $500 million that is a loan to build the Model S factory not for the roadster, I don’t believe they have actually received any of those funds yet. Stuart Koford Cincinnati, OH THE REAL REASON FOR DRAIN WIRES

In the November issue of Design News, you write, “The twisted-pair cable, A, has


MAIL Readers Sound Off a 100 percent aluminum-foil shield and separate ‘drain’ wires that connect to the shield and simplify a ground connection. These separate wires have a lower resistance than the foil alone,” “An Update on Shielding,” (DN 11/09, http://designnews.hotims.com/23129-513). The shield is not “100-percent aluminum foil.” No. Aluminum foil would be too delicate; it would tear if the cable was bent. Therefore, the so-called “foil” is actually Mylar plastic. Of course, Mylar is non-conductive and so would not be an effective electromagnetic shield at all. To make it into a shield,

high-frequency effectiveness of the shield because the thin drain wire is inductive at high frequencies. Therefore, the length of the drain wire must be kept as short as absolutely possible. A metal shield blocks an electric field. Even an ungrounded shield will do that. An electromagnetic wave consists of and requires both an electric and a magnetic component. A shield will block the electric field component of the electromagnetic wave and without its electric field component, the electromagnetic wave can’t go on. A typical shield on a shielded cable is very ineffective at blocking magnetic fields. Chuck Gollnick Beaverton, OR INCREASING THE HEFT?

I am interested to know if the handset for your industrial-strengthened phone has some additional “ballast,” “Heft: It’s the New Quality Attribute,” (DN 10.09, http://designnews.hotims. com/23129-514). Many years ago I opened up a non-working phone’s handset to find a slab of lead. At the time, I figured it was there to increase the heft, and therefore the perceived quality, but now I also wonder if it improved the reliability of the hook switch, allowing a stiffer spring on the switch. Ed Barney North Springfield, VT HEFTY PLASTIC

the Mylar plastic film is metallized with a thin layer of aluminum on one side. The drain wire serves two purposes: first, if the cable is bent particularly hard, the metallization at that point may crack and open electrically. The wire which runs along the outside of the Mylar film will provide a continuous path to bridge over the crack. Of course, the shield is no longer 360-degrees at that point and high-frequency performance is compromised. Second, the drain wire provides a way to connect to that thin aluminum layer for connectorization. It’s very hard to solder to aluminum at all and when it’s a whisper-thin coating on top of Mylar plastic, it’s impossible to solder to. Crimping is also not practical with good results. This connectorization is where most people undermine the effectiveness of a foil shield. Grounding through the drain wire seriously compromises the

I have friends in the phone industry, and remember when (gosh, I’m feeling old) the new model phones were starting to come out in the early 80s when the government broke up Ma Bell. They actually put a steel weight in the plastic handset so that it would have the “feel” that everyone had been used to. Bob Kovich Columbia, MD MORE U.S. MANUFACTURING, PLEASE

The ice cream scoop is a Hamilton Beach. I found a picture of the model 67 scoop (ours is model 66) on the Web at http://designnews.hotims. com/23129-515. I checked the Hamilton Beach website and

did not find the ice cream scoop, so I assume Hamilton Beach stopped making it, which is too bad! If I had the money, this is one of many products I would like to manufacture in the United States (under some kind of agreement with the original manufacturers). I would have to think up a clever name for the company, a name that denotes our country’s manufacturing and engineering design heritage, as well as solidly designedmanufactured-tested products. OK, for a start, the name of the company could be “USA_Designed_Built_Tested_Heritage_Products” or “USA_Heritage_Products.” Please let the manufacturing community know that my wife and I, and many other customers who frequent Sears, Home Depot and Williams-Sonoma, look for a U.S. flag or “made in the USA” on the box to identify a product made in the USA; however, many times we cannot find such a product. That is why Jill, my wife, bought a German Leifheit step stool from Williams-Sonoma for $80, when she could have bought many others for $20-$25. We have bought plenty of inferior products, only to have to eventually dispose of them because they are not worth fixing. Quality products such as this ice cream scoop and step stool will last for decades, becoming a superior purchase. Tom Scheffelin Gold River, CA ‘HEFT’ IS NOT NEWS

The picture you show in the October issue of Design News looks like a Dexter Russell S3A pizza cutter. Dexter Russell designs and sells its products to commercial kitchens where there is plenty of aluminum cookware, and no significant etching problem. So there must be more to the story than you got at first glance. This was not the main point of your piece, but you took a pretty hard whack at a high-quality manufacturer as an introduction to your point. To your point, of course “feel” is important in handheld products. It’s why BlackBerry markets some phones to men and

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MAIL Readers Sound Off some to women, and it’s why Canon and Nikon are able to both stay successful in a crowded marketspace; they have different, distinct feel and each one appeals to a different slice of the photographer population. There is no news in “heft” as a design parameter. I suggest that before your publication publishes an obvious bash, such as this, someone attempt to verify the story. Paul Malchodi Acton, MA AND WHAT’S WRONG WITH A LITTLE PIZZA?

In October’s Field Report, “Heft: It’s the New Quality Attribute,” (DN 10.09, http://designnews.hotims. com/23129-514), I immediately recognized the Dexter brand pizza cutter pictured as the same one I purchased some 20 years ago at a commercial restaurant supply company, and continue to use today, though mine lacks the NyLock fastener you mentioned. The manufacturer (Dexter) must have changed it after someone found a nut in their pizza! And why a nut and bolt instead of the usual rivet? Because it’s one of the few pizza cutters designed to allow the user to replace the blade. At one time, the term “commercial” quality meant that the product was built to withstand heavy-duty use. The domestic kitchen equipment manufacturers co-opted that term some years ago and have labeled just about everything commercial, hoping consumers would believe their products were tougher and would last longer. True, commercial food service equipment, such as ranges, do last longer and usually have a Spartan look. The lack of “bells and whistles” certainly contributes to their longevity … less frills … fewer problems! Your mention of the term “heft” recalls a story I heard many years ago … and one hopefully you can get confirmed (or find a denial). When Apple produced its initial “desktop” computer, and engineering

unveiled the prototype production unit it to the marketing staff, they passed it around and remarked: “It’s too lightweight! No one will pay for this… It feels empty…” Allegedly they inserted lead weights inside the case to give it some heft! A great story I thought … true or not. Marc R. Mann San Diego, CA LARGE, HEFTY ITEMS IDEAL FOR BIG HANDS

As a regular winner of who’s-got-the-biggest-hands contests at social gatherings, I usually go for large-handled and hefty items when it comes to small-hand tools, such as kitchen gadgets. Curiously, the oversized gadgets made for the elderly and otherwise challenged, fit my hands just about right. Regarding heft in telephones, telephone manufacturers have known of the heft desired in land line phones for at least 20 years. Exit the rotary dial and supporting hardware, touchtone phones were nothing but plastic shells with small circuit boards inside. It used to be common practice to weight a phone with a chunk of steel (usually a piece of bar stock clipped into place), almost always the base of a corded table top model, and usually the handset, as well. I’m sure that if any corded phones are even still made anymore, steel as a ballast has priced itself right out the consumer telephone. Greg Feneis Belmont, CA

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RANT Really Opinionated People DR. BIJAN K. SHAHIDI, PRINCIPAL CONSULTANT, ENGINEERING PRODUCTS INC.

Auto Industry’s Loss Is a Gain for Others TALENTED DESIGN ENGINEERS MOVE TO GREENER PASTURES DESPITE RECENT DECLINES IN THE

auto industry, today’s vehicles are certainly quieter, more durable and safer than 10 years ago. Much of this is due, in no small way, to increasing sophistication in the design and simulation tools available to engineers, particularly finite element analysis (FEA) software. In my years as a vehicle CAE manager, I personally witnessed the explosion of FEA capabilities and applications. The software helped my design and development teams model, simulate and analyze the behavior of automobiles under a wide range of loads and conditions. Our expertise evolved along with FEA, going from “classic” linear contact simulations to complex, nonlinear analyses such as those found in Abaqus fullbody noise and vibration (N&V), which simulates rolling tires, wind loads and more. Our CAE models’ fidelity became so good that over time we found less and less need to build physical prototypes for validation and comparison. High-quality simulation results helped us present realistic cost forecasts to our senior management before they signed off on any production go-ahead. Such simulation-driven advantages will continue to prove their worth to the automotive industry as it focuses on vehicle redesign as the foundation of its revival strategy. But the future potential of CAE is certainly not limited to automakers. Given today’s economic environment, manufacturing companies across the board are being pressed more than ever to improve engineering efficiency, lower development costs and accelerate product innovation. I see simulation playing an increasingly prominent role in helping every industry achieve those goals. As compute power goes up, the models get finer and finer and the software gets better aligned, you’ll

see much tighter integration all around. Eventually, you won’t see anything — except 3-D “reality” — at all. The automotive industry has certainly been one of the major staging grounds for large-scale use of FEA. The application of N&V analysis alone has grown tenfold in the last decade. And automotive engineers eager to share their results have spread the news of these capabilities at regional and global engineering conferences. The CAE “lessons learned” in automotive are feeding into other industries including construction, heavy vehicle, military, off-highway, aerospace and shipbuilding engineering. But newer, mechanized industries such as life sciences are learning that the design challenges they face in N&V control of machinery and devices — such as oxygen delivery breathing apparatuses or hearing aids — can also benefit from such knowledge. As a result of the automotive industry shedding talented engineers, we are likely to see an acceleration of FEA/N&V knowledge transfer to medical, pharmaceutical and other industries that are in a better position to hire skilled engineers. Those automotive companies willing and able to continue investing in realistic simulation technology and skilled staff will certainly benefit as they develop the next generation of green vehicles. But the cat is out of the bag: Engineers who excel at using N&V simulation technology will be in high demand elsewhere — as innovation leaders who can apply their knowledge of FEA across many other industries, as well. Dr. Bijan Shahidi was a technical expert, supervisor and manager of the CAE department at a major automotive OEM for 18 years. He is now principal consultant for Engineering Products Inc.

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hat is feasible and what is infeasible in a given set of circumstances? Can we say something about achievable performance of all possible designs? This is a fundamental engineering question. Central to the design of real systems are inescapable performance limitations that evolve from the laws of nature. The ability to identify performance trade-offs and limitations (at both the component and integrated-system level) and their sources, and quantify their impact, is essential in mechatronics design and control. This information helps one compare potential designs and then optimize a system design to either remove some of the limitations or stretch the bounds imposed by these limitations to a higher level. The importance of fundamental performance limitations in the design, analysis and control of mechatronic systems cannot be overemphasized. Unfortunately, this subject is rarely addressed in any academic courses. Professor Kamal Youcef-Toumi of MIT and Professor Karl Astrom of Lund University have been strong proponents, and the 1997 book â&#x20AC;&#x153;Fundamental Limitations in Filtering and Controlâ&#x20AC;? by M. Seron, J. Braslavsky and G. Goodwin is a key reference. A fundamental example of a performance limitation is given by the well-known Sampling Theorem of Shannon and Nyquist, which states the highest frequency that can be unambiguously represented by discrete samples is half the sampling rate. The X-29 flight control design, cited by Gunter Stein in his Bode Lecture, is an excellent example of the importance of knowing these fundamental limitations. At one flight condition, it was desired to have a 45-degree phase margin. Unfortunately, the system possessed an open-loop unstable pole and a nonminimum-phase zero, and a 45-degree phase margin was infeasible! Much effort was wasted trying to meet this design goal when clearly (at least to the well-grounded controls engineer) it was not attainable! These fundamental limitations typically take three forms. Some are in the form of algebraic equations, e.g., T(s) + S(s) = 1 holds at all frequencies, where T(s) and S(s) are the complementary and sensitivity transfer functions, respectively.

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One cannot achieve good disturbance rejection (s) and attenuation of measurement noise (t) both at the same frequency. Other constraints take the form of a frequenBY KEVIN CRAIG cy-domain integral on a closedloop transfer function such as S(s). Kevin C. Craig, Ph.D., The Bode integral constraint is an Robert C. Greenheck example. Reducing the sensitivity Chair in Engineering at some prescribed frequency range Design & Professor of results in large values of sensitivMechanical Engineering, ity at other frequency ranges. This College of Engineering, trade-off is worse in the presence of Marquette University. open-loop unstable poles and nonFor more mechatronics minimum-phase zeros. The third news, visit www.mechatronicszone.com. type takes the form of time-domain integral constraints on a system signal such as the feedback error. So what is the big picture here? The core of any mechatronic system design team will consist of mechanical, electronics and computer systems engineers. Control is pervasive and all need to thoroughly understand its benefits and application. Developing simple, integrated design models to evaluate concepts will necessarily involve physical system dynamics, and most likely compliance, as well as choices of sensor and actuator locations. This will be represented mathematically by poles and zeros of transfer functions. These locations, coupled with fundamental laws, will inform what is possible and what is not in performance. Ignorance is no excuse! My eyes have been opened wide to this most important aspect of mechatronic system design. The references are there and we are always on a learning journey. Visit the Mechatronics Zone for the latest mechatronics news, trends, technologies and applications: http://designnews.hotims.com/23129-516

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Regulations

PLAYING BY THE RULES A growing number of regulations are changing the way medical products are created BY TERRY COSTLOW, CONTRIBUTING EDITOR

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egulations and standards are playing a more significant role in medical system design every year. Design teams that were once only tangentially impacted by regulations must now consider a number of different rules throughout the design cycle. Regulators say there’s good reason for strengthening their focus on design. An FDA study of data from the late 1980s found that almost half of all medical device recalls stemmed from design flaws. Environmental watchdogs note that the components used in a large percentage of medical products have included too many materials that create environmental problems. The focus on the design side began back in the late 1990s, when the FDA began requiring companies to follow some design control principles. The 21 CFR Part 820 is one of the critical aspects of the FDA’s family, focusing on design controls. While this, and other FDA documents, set many of the rules engineers must follow, they aren’t the only ones. A host of environmental regulations now impact the majority of system designs, with standards bodies also creating specifications that engineers must integrate into their plans. MANY TECHNIQUES

Suppliers have a range of techniques for addressing these requirements. MasterControl of Salt Lake City, UT contends that using Web-based tools provides a holistic way to manage the design control process. This cloud concept ensures all data is stored in the same place, and it makes critical revision tracking simpler, making the audit process smoother. As these design concepts change, many OEMs are turning to contractors who can handle all aspects of the design. That’s another way to keep the entirety of the project in one place. “Over the past few years, we’ve seen more demand for turnkey outsourcing as companies look for outside help earlier in the design process,” says Dave Schiff, director of engineering for the Bresslergroup Inc., an industrial design firm based in Philadelphia, PA. Regardless of who does the engineering work, the medical [ w w w. d es ig n n e ws.c o m]

FDA regulations altered the way the Bresslergroup Inc. designed its needle guard and moved it into production.

industry is changing the way its products are designed. Companies as diverse as National Instruments and The MathWorks are urging companies to adopt model-based design and simulation to help ensure the requirement specifications are correct. When design ideas are validated in a virtual environment, errors can be spotted earlier in the process when they’re easier to fix. But simply using modeling won’t meet the demands of regulators who want lots of documentation on the reasoning behind the testing techniques. “The validation and verification processes need to be proven,” Schiff says. This approach also helps keep costs down, since fewer prototypes are needed. Using models also helps companies perform risk assessment. The Occupational Safety and Health Administration is putting more emphasis on risk assessment, urging designers to determine acceptable risks. This approach is being adopted fairly broadly as more engineers understand its benefits. “We’re doing more and more in failure mode effect analysis at the design phase,” Schiff says. “At each step in the usage scenario, we look at the likelihood of something happening and determine the impact of the problem. Then we figure out how to eliminate or mitigate the problem.” Using risk assessment helped the Bresslergroup find potential problems with a needle guard that protects caretakers from

D E C E MB E R 2009 ME DICAL TE CH NO LO GY / A S UP P LE ME NT TO DE S I GN NE WS S1


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inadvertent needle sticks. A spring plays a critical role, so the tolerances used to manufacture it have to be extremely tight. “If the spring isn’t molded appropriately, it might not snap over the needle. We specified a tolerance for the spring force and made that part of the verification test,” Schiff says. “A document that describes the tolerances for this spring are one part of the handoff that goes to manufacturing.” That’s a prime example of the way the designer’s role extends into manufacturing. Maintaining data integrity is another. Companies must first ensure that all the CAD files compiled during design are translated correctly when data is converted to the formats used in manufacturing. When either manufacturing or design teams make changes, each side must be sure the alterations don’t bring any unexpected consequences. Documentation and communication are key facets of this issue. “Everything has to be tightly tied to manufacturing,” Schiff says. “You also need much more of a paper trail.” FOLLOWING THE RULES

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While design engineers worry about documenting their side of the job, they also have to keep an eye on documents created by regulators and standards bodies. Keeping track of updates to standards is becoming an important aspect of design management. “There can be all kinds of catastrophic results from not having all the proper standards,” says Alison Ruger, business development director at IHS Inc. of Englewood, CO. If a product uses 10 standards and regulations that each update once a year, design teams with a quick 18-month development and approval cycle will need to factor in around 15 specification changes. If a material is banned or a specification is revised significantly, products could be barred from sale in some countries or lose market share because they’re out of date. In electronic designs, regulations like RoHS, REACH and WEEE continue to expand the number of banned substances that already includes lead, cadmium and mercury. More plastics are also being added, and the U.S. government is even proposing a bill that will make vendors keep track of where ore for tin and other materials was mined. “There’s a proliferation of environmental regulations,” Ruger says. Though engineers realize it’s important to document all the actions they take to create solid designs, it’s not something most of them want to do. “Bookkeeping and document management can be time-consuming, usually taking a dedicated full-time or halftime person,” Schiff says. “It can bog down a rapid turnaround project if the engineers are keeping track of documentation.” However, many product developers agree that while the paperwork issue is annoying, the concepts and techniques connected to them have worthwhile payoffs. “Good design controls lay the foundation for the healthy design and development of medical devices in general,” says Kathryn Kukulka, regulatory affairs director at Omnica Corp. of Irvine, CA. “Properly instituted, these guidelines provide the manufacturer with the opportunity to address and/or correct problems early in the process.” [www.d esignnews .com]


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Materials Processing

Molded Magnesium Parts Create Rugged Housing DynaVox wanted to combine light weight and toughness in its new Xpress device BY DOUG SMOCK, CONTRIBUTING EDITOR, MATERIALS AND FASTENING

The Xpress is a handheld device that allows users to choose photos that are translated to spoken words.

S O U R C E : D Y N AV O X

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njection molding magnesium? It sounds far out, but, in fact, it’s increasing in popularity as a way of solving many design engineering problems. Case in point: A Pittsburgh-based company called DynaVox Mayer-Johnson wanted a sturdy, but lightweight case to house one of its new speech communication tools — the DynaVox Xpress. It’s for adults who suffer from strokes, ALS and brain injury, children with autism and Down syndrome, and others with speaking disabilities. The case also had to provide EMI/RFI shielding and be cost-competitive. And the product needed to be designed and launched in a hurry — in time for back-to school this past September. “Part of the design goal was to make the Xpress as small and lightweight as possible,” says Rick Severa, director of product design at DynaVox Mayer-Johnson. “But we also have to allow for all of the functionality, including speakers.” The Xpress is designed so it can project conversations outdoors, in restaurants, classrooms and even school cafeterias. “One of the other big things for our

users is the battery capacity,” says Severa. “Laptop computers typically provide two to three hours of battery life. DynaVox devices require longer operating times. That means larger batteries.” Users of the speech communication tools have unique challenges. As a result, they must be rugged. “Children with autism and other conditions sometimes have behavioral challenges and will drop or throw devices. We need to make sure the device can stand up to everyday use in these environments,” says Jim Shea, vice president of marketing at DynaVox. DynaVox used a blend of polycarbonate and ABS for some early designs of its speech communication devices. The company’s design and production partner, Phillips Plastics of Hudson, WI, recommended it consider cases made with the thixomolding process, in which liquid magnesium is molded. Phillips Plastics is unusual in the molding world because it molds plastics, powdered ceramics, powdered metals and molten magnesium. “The magnesium moldings have thin walls and their strength-to-weight ratio is astronomical,” says Severa. The big advantage of thixomolding over die casting for magnesium is wall thinness, according to Dale Ek-Pangerl, the project engineer at Phillips Plastics’ magnesium injection molding facility. “You get lighter weight with thixomolding,” he says. “We can do thinner walls with less draft in the thixomolding process,

S4 M EDI C A L T EC HNO L O GY / A S U P P L E M E N T T O D E SIG N N E WS D E C E MB E R 2009

as opposed to magnesium die casting. Another big issue is that you can design the part as a plastic part and thixomold it. You have to redesign in order to die cast it.” DynaVox did in fact migrate a PC/ABS design from an earlier housing for use in the thixomolded housing for the Xpress. Housings made with plastic have thicknesses around 0.080 inch, or 80 mils (2.03 mm). More typical for molded magnesium is 0.060 inch, but in some applications gauge can drop to 0.030 inch. Severa also says the thixomolded magnesium walls hold tolerances very well. There are other advantages, as well. “We’re using the magnesium housing as a giant heat sink,” says Severa. “We attach the processor directly to the magnesium, and don’t use fans for cooling.” In addition to reduced weight, background sound is significantly reduced, he says. The magnesium housing retains electromagnetic fields within the Xpress and protects against outside fields. Plastic boxes require various sophisticated solutions for electronics’ shielding. For example, General Motors is debuting a new plastic case radio with insert-molded shielding on the Tahoe GMT900 family. In the patented innovation, steel mesh screens are robotically placed inside injection molds which are filled with 16 percent glass PC/ABS. Previous designs used a sheet metal case that required significant assembly. The Xpress is equipped with a standard battery pack that lasts approximately 31⁄2 [www.d esignnews .com]


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Materials Processing hours and weighs 1 lb 8 oz. An optional battery pack lasts approximately 8 hours and weighs 2 lb 1 oz. The battery packs are self-contained with their own magnesium housings. The battery compartment has a slide and latch mechanism, requiring an undercut and action on the tool. In all, there are three molded magnesium components per unit. Speakers are mounted to an IR transparent front grille made of polycarbonate. There are several other plastic components, which are primarily molded by Phillips Plastics from polyacetal. DynaVox Mayer-Johnson began in 1983 as a Carnegie-Mellon University student project to help a young woman with cerebral palsy communicate. A product called the EyeTyper allowed individuals to spell messages with their eyes. Messages were then “spoken” by a computerized voice. DynaVox now sells a full line of speech devices that address various physical and cognitive needs. The Xpress, for example, can be loaded with software to enable speech for people who suffer from autism, ALS (amyotrophic S O U R C E : D Y N AV O X lateral sclerosis or Lou Design goals for the Xpress led Rick Gehrig’s Disease), Severa, above, to select magnesium cerebral palsy, Down syndrome, neurological molded parts for the housing. conditions, stroke or traumatic brain injury. Autistic children, for example, choose images that are translated to spoken words. The devices can qualify for reimbursement from Medicare, Medicaid or private insurance. School districts may also buy devices for students. “DynaVox is the biggest company in the field and the market we’re addressing is only 5 percent penetrated,” says Jim Shea. “Many of the people who could use these devices don’t even know they exist.” Because the Xpress is a portable device with a large potential student market, market timing was critical. Phillips Plastics provided the design services, as well as prototyping, tooling and manufacturing for all of the relevant parts in the Xpress. Phillips Plastics is one of the largest custom magnesium injection molders in North America, with seven specially made injection molding machines ranging in clamping force from 220 to 850 tons. It’s a fast-growing business with applications coming in the medical and military, as well as various consumer applications. Temperatures and pressure are higher than plastics injection molding, requiring sturdy tools and presses. Magnesium melts at around 1,100F, compared to 300-400F for higher-level plastics. Designs are very close, but Ek-Pangerl recommends slightly more generous radii for magnesium parts to accommodate material flow. Check out Phillips Plastics’ full range of molding capabilities at www.phillipsplastics.com. [www.d esignnews .com]


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To manufacture an innovative device for relieving sleep apnea, Ventus Medical found a valuable partner in Phillips Plastics

I

n the U.S. alone, some 50 million people suffer from sleep apnea, a breathing obstruction that plays havoc with a good night’s rest, but there’s been a lack of treatment options to meet patient needs. Ventus Medical, a Belmont, CA, company, hopes to change that with PROVENT® Sleep Apnea Therapy, a tiny device that attaches discreetly over the nostrils and harnesses the user’s own breathing to create air pressure. When the user breathes in, PROVENT’s MicroValve opens completely, and a normal breath is taken. With exhale, the MicroValve partially closes, causing resistance and increased air pressure in the airway. Result: an open, stabile airway for improved breathing. The clinically-proven prescription device has already attracted the attention of the medical community and captured awards for design and innovation.

Unlike the continuous positive airway pressure (CPAP) device that includes a face mask and air pump, the tiny Ventus PROVENT therapy (left) attaches directly to the nostrils and harnesses the user’s own breathing to create air pressure.

Key goal: Cost-Efficient production Yet with a device that targets such a large potential market, Ventus faced the challenge of keeping costs under control for high-volume manufacturing. After developing an initial design, Ventus evaluated manufacturers with custom plastic injection molding and medical device manufacturing capabilities. The organization ultimately chose Wisconsin-based Phillips Plastics to manufacture PROVENT. “Phillips Plastics excels in plastic injection molding,” says Shapour Golzar,

senior manager of Operations and Supply Chain, Ventus Medical. “They also provide the technical expertise in medical device and contract assembly that we require.” John Fraboni, VP of Operations and Supply Chain at Ventus, adds that the PROVENT design was nearly complete when Phillips entered the picture, but the partnership between the two companies resulted in important enhancements to the product’s design for better manufacturability and automation.

Help for Harried Sleepers Millions of Americans are robbed of peaceful sleep by obstructive sleep apnea (OSA), a chronic disorder characterized by frequent pauses in breathing or shallow breaths during sleep. After such disturbances, normal breathing resumes, sometimes with a loud snort or choking sound. PROVENT is held in pace Those suffering from the condition often with a hypoallergenic move from deep to light sleep, resulting in adhesive. poor sleep quality that can make one tired or sleepy during the day. Untreated OSA can heighten the risk of high blood pressure, heart attack, heart failure, stroke, diabetes and obesity. It can also increase the likelihood of irregular heartbeats and driving or work-related accidents. The patented PROVENT® therapy offers a simple, noninvasive treatment for OSA. It features a novel valve design that attaches over the nostrils and secures in place with a hypoallergenic adhesive. Unlike the cumbersome continuous positive airway pressure (CPAP) machine, which requires a face mask and air pump, the compact PROVENT device is disposable, easy to use, and requires no cleaning or maintenance.

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S P E C I A L A DV E RT I S I N G S E C T I O N

Provent Assembly

Upper Valve Body

A Full-service Medical Resource

Flapper

Lower Valve Body

Phillips Plastics worked with Ventus Medical to develop an automated process to pick and place an ultrathin silicone part known as the flapper, which fits between PROVENT’s upper and lower valve bodies and helps regulate air flow.

Design for Automation Perhaps the biggest challenge involved developing an automated process to pick and place a silicone part known as the flapper, a key component in regulating air flow within the device. Initially provided to Phillips from an outside supplier on sheets, the miniature, 0.003-inchthin flapper needed to be affixed to a roll stock for cost-effective automation. Phillips and Ventus worked closely with the flapper supplier to improve the roll-stock design and alter the makeup of the silicone for easier handling. In addition, the partners collaborated with other suppliers on equipment to assemble PROVENT’s components. The final automation design includes pick-and-place robots for handling the flapper and the adhesive subassembly, as well as bowl feeders for the device’s polycarbonate components. “What appeared to be a simple, straightforward device upfront turned out to be a very challenging program [ w w w. d e s i g n n e w s . c o m ]

The partnership that Phillips Plastics forged with Ventus Medical builds on Phillips’ more than 20 years of experience in producing tens of millions of parts for medical companies. During that time, Phillips has made an extensive commitment to the industry, including: • FDA registration both as a device manufacturer (21CFR part 820) and as a drug packager (21CFR parts 210 and 211). • Over 130,000 square feet of production space dedicated to medical, including extensive clean room facilities. • Dedicated engineering teams assigned to medical manufacturing. • Robust Quality Systems and production controls supporting the company’s medical operations. • Secondary operations, including sonic welding, spin welding, laser etching and ultrasonic cleaning. With these comprehensive facilities, Phillips has provided medical design, production and assembly services for companies ranging from start-ups to industry giants. Among the long list of devices Phillips has produced: • High-tolerance molded parts for pens and syringes used for insulin injections. • Infusion pumps, glucose meters and lancet devices for diabetics. • Surgical instruments for endoscopic and laparoscopic procedures. • A spinal surgery kit requiring more than 40 components. • An epinephrine injector for allergy suffers. • A hearing aid that blends fashion and cutting-edge technology. Phillips’ engineers stand ready to take on your project, providing services ranging from industrial and mechanical design to prototyping, tooling and volume production and assembly.

in order to automate flapper handling,” explains Phillips project engineer Steve Harmon. “Through due diligence, hard work, and close cooperation, Phillips and Ventus succeeded in developing a cost-effective, automated, and efficient manufacturing process for PROVENT® Therapy.” Among other important automation steps, Phillips determined that eight-cavity tooling would be the best solution for speedy, cost-effective production of the device’s upper and lower valve bodies. Such automation steps will help Ventus meet increasing demand for PROVENT Therapy in new geographic markets. Says Fabroni of Ventus: “Phillips Plastics has proven to be an extremely collaborative partner on this project. They have demonstrated the forward thinking that will get us to the volume, pricing, and performance targets required to make PROVENT® Therapy a success in the marketplace.” With solid manufacturing methods in place, Ventus can look ahead with confidence as interest builds for its new product. This year, PROVENT

won a coveted Medical Design Excellence Award from Medical Device and Diagnostic Industry magazine, as well as runner-up honors in The Wall Street Journal’s Innovation Awards. Ventus also cites new clinical data presented at the June annual meeting of the Associated Professional Sleep Society that further confirm the device’s utility in treating obstructive sleep apnea. “These new data offer additional evidence that PROVENT Therapy is clinically-proven and truly designed with the patient’s needs in mind,” said Philip Westbrook, MD, chief medical officer at Ventus and emeritus professor of Medicine at UCLA. For more information on medical design and manufacturing services at Phillips Plastics: http://designnews. hotims.com/23128-130

DECEMBER 2009 MEDICAL / A SUPPLEMENT TO DESIGN NEWS S9


Rapid Prototyping

Rapid Prototypes Speed Diabetes Equipment to Market

Pinching Element

Removable Cassete

Tubing

Motor Mount

Motor-Drive

Biorep uses an Eden250 to develop fast parts to test ideas and sell concepts to management

Housing Selector Disk Cam Disk

BY DOUG SMOCK, CONTRIBUTING EDITOR, MATERIALS AND FASTENING

The pinch manifold is mechanical rather than electromagnetic to avoid spills in the event of a power failure.

it didn’t exist in the market, so we had to design and build it.” Biorep, which was founded in 1995 as a pro bono engineering partner to the Diabetes Research Institute (DRI) in Miami, relied on its own machine shop to make prototypes. The workload grew, and included development of equipment used to isolate islet cells from the pancreas. This enabled advanced-stage diabetics to receive transplants, allowing them to live insulinfree. The work resulted in several honors for the president and co-owner of Biorep, Ramon Poo (pronounced Poe). Biorep then began to outsource models to service bureaus to cope with a mushrooming workload. “When we outsourced 3-D printed models, they were often more expensive than the cost to machine them in-house, and it wasn’t much faster,” says Echeverri. “We knew we could really accelerate our design productivity if we had the ability to print a part overnight, in our office.” Seventeen metal and plastic parts for the pinch manifold were prototyped on the Eden250, a smaller, entry-level machine. Eight polyacetal parts are used to pinch the tubing, shutting off the flow of fluids. There are also two parts made of Ultem, a polyetherimide engineering plastic developed by Sabic Innovative Plastics. Biorep had previously used Ultem in the Ricordi Chamber, which isolates and purifies insulin-producing cells from a donor’s pancreas. The two metals used in the manifold are stainless steel and anodized aluminum.

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medical device manufacturer in Florida is getting to market faster with better designs through use of a 3-D printing system to rapidly make prototypes. “One of the great things it has enabled us to do is test the proof of concept first without worrying about details such as manufacturing,” says Felipe Echeverri, engineering director of Biorep Technologies in Miami. “The other thing is that we can leave it unattended overnight.” The Eden250 3-D printing system from Objet Geometries was used extensively in the development of a patent-pending pinch manifold. Pinch valves are used in medical labs to keep fluids, such as blood, in silicone tubing from coming into contact with any equipment components. “There are many pinch valves out there, but none that are noncontact where you can select multiple tubes,” says Echeverri. “We knew

This illustration shows several parts for a pinch manifold made from stainless steel and aluminum that were first prototyped on an Eden250.


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Rapid Prototyping

Miniaturizing a Surgical Drill Using High-Energy Lithium Batteries BioAccess, which manufactures a cordless, single-use surgical bone drill, recently designed an alternative version to address the needs of orthopedic surgeons who prefer surgical equipment that is smaller, lightweight and ergonomically designed. The device utilized alkaline cells that performed well and offered excellent reliability. However, to reduce weight and extend the power ceiling of the drill, BioAccess chose a battery pack consisting of six Tadiran TLM1550-HP AA-size high-power lithium batteries, which delivered an open circuit voltage of 4.1V, 80 percent greater energy density and higher capacity than equivalent alkaline batteries, and were able to handle 15A high current pulses with 5A maximum continuous load. Converting from alkaline cells to TLM high-power batteries resulted in a 36 percent weight reduction. An equivalent alkaline battery pack would require 3 times the weight and 2.5 times the volume (requiring 15 AA-size alkaline batteries versus 6 AA-size TLM-1550-HP batteries). TLM batteries also permitted more active drill time (30 to 40 sec at a time, with 20 to 30 cycles), as well as more instantaneous power. These performance advantages have been validated by operating room surgeons who appreciate the increased power and ergonomic comfort, resulting in less fatigue and more efficient drilling cycles. BioAccess’ small bone drill was designed for single use at ambient temperature. However, these batteries can also withstand 125C temperatures required for autoclave and chemical sterilization cycles. These longlife batteries are ideally suited for medical devices such as automatic external defibrillators (AEDs) that can go unused for years, but must work reliably in life-threatening situations. Unique attributes such as high capacity, high energy density, extremely long life and an extended temperature range make Tadiran TLM cells an excellent choice for other medical applications, including cauterizers, CPR resuscitation equipment and handheld power devices used in hospitals, clinics or field responders. Tadiran http://designnews.hotims.com/23128-501

Fluids only come into contact with the tubing, which is disposable. The prototypes were used to sell the concept to management. Biorep’s manifold, which is now for sale, uses a series of cams and a motor to control fluids in multiple channels. Functional prototypes were machined, and at that time parts were designed for manufacturability (draft angles, gate locations and so on). Another technology developed jointly between DRI and Biorep is a silicone membrane petri dish. A standard Prototyped on an Eden250 3-D printing system, the plastic dish allows oxygen in silicone petri dish enhances oxygen permeability. from the top. Scientists at the Diabetes Research Institute wanted to test a dish in which oxygen could reach from the top and the bottom. “Silicone is permeable to oxygen, so we decided to try to create a silicone membrane petri dish,” says Echeverri. “DRI scientists developed a proprietary silicone blend that enhances oxygen permeability — we call the design the “Oxygen Sandwich” because it envelops the cells in oxygen from above and below.” Echeverri’s team (which includes eight design engineers and 11 seats of SolidWorks) prototyped parts on the Tubing Eden250. “The final design of the membrane Removable Cassete is just 300 microns thick — strong enough to be handled in a lab without Pinching Element getting damaged and taut enough to prevent sagging. We did a lot of prototyping with different configurations to arrive at that conclu- Motor Mount sion,” says Echeverri. It took just six Cam Disk months to go from concept to field testing. “Six months is an incredibly short time Selector Disk to get a medical device into field testing,” says Housing Echeverri. “Our ability to produce rapid prototypes in-house cut the development time Eight polyacetal components pinch the tubing, shutting in half.” off the flow of fluids.

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A D V E R T O R I A L


PROVEN

Cut the size. Raise the reliability.

25 YEAR OPERATING

LIFE Formerly powered by alkaline batteries, BioAccess cordless bone drills are now powered by TLM-1550-HP batteries that deliver an open circuit voltage of 4.1 V along with high current pulses of up to 15 A with 5 A maximum continuous load. An equivalent alkaline battery pack would require 3X the weight and 2X the volume (requiring 15 AA-size alkaline batteries versus 6 AA-size TLM-1550-HP batteries).

When BioAccess set out to make a lighter, more powerful cordless bone drill they chose Tadiran TLM-1550-HP batteries over alkaline cells. The result was a 36% weight reduction, greater torque and faster drilling speeds for ergonomic benefits such as reduced fatigue and more efficient drilling cycles, plus the improved reliability of a 25-year battery. This is just one example of how Tadiran Lithium batteries are performing miracles for pacemakers, AEDs, infusion pumps and a variety of handheld medical devices.

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Medical Technology

Q&A

Analog Front End Solutions SHRINK Ultrasound Equipment BY KAREN AU G U S T O N F I E L D, E D I T O R I A L D I R E C T O R

D

esign News talks with Scott Pavlik, marketing manager, Healthcare Segment Team, Analog Devices, about the company’s evolving analog front end solutions for ultrasound platforms. There have been some amazing advancements in medical technology over the last decade. What’s going on in the area of ultrasound equipment? Over the last decade one of the major trends in ultrasound from an equipment perspective has been the advent of portable systems, both cart-based and handheld devices. This has given health care providers unprecedented flexibility, including use of these devices in ambulances and field hospitals and by rescue crews. What are some of the biggest challenges that design engineers are confronted by in this area? As is the case with any evolving technology, what’s complicated for engineers is that they need to deal with a number of competing design goals simultaneously, including a longer battery life, better image quality through capabilities like fine resolution and deeper penetration, improved reliability and lower cost. For their designs to be competitive in the marketplace, there is a whole host of trade-offs and issues that they have to deal with. What is Analog Devices doing to help designers cope? In 2007, Analog Devices introduced the first device to integrate a complete eightchannel ultrasound receiver on a single chip, with a low-noise amplifier, variablegain amplifier, anti-aliasing filter and

a 12-bit ADC — which takes a direct signal into the digital domain. For engineers this was significant, as it allowed them to significantly reduce the footprint of the PC board, which obviously had an impact on the overall size and weight of the product, and it also allowed them to pack more measurement channels into a given area. That’s significant, because generally speaking, the higher the performance, the higher the number of channels. In addition, an integrated front end solution reduces the losses and inefficiencies that occur when laying out individual components on a board. A year ago Analog Devices expanded its offerings in this area with two new products, the AD9272 and the AD9273. What are some of the key features? These new devices are designed to maximize image quality and reduce power consumption. Some of the key features include a Serial Port Interface that allows engineers to customize the noise and power performance, low input noise current and high input dynamic range. Specifically, the AD9273 has power dissipation lower than 100 mW per channel @ 12-bits and 40 MSPS, which is instrumental in extending the battery life of portable ultrasound equipment. Where is the market evolving? Processor speeds will keep going up, and the design engineers will continue focusing on performance and adding new features. Reduced power and size will continue to be the key areas of focus moving forward. Now where have we heard that before?! [www.d esignnews .com]


Robotics

An Autonomous Device for Upper Limb Stroke Rehabilitation Realistic sensory feedback enables robot to customize its response BY JOHN WILLIAMSON, CONTRIBUTING WRITER

F

or the 400,000 people affected by stroke, rehabilitation is an important part of recovery. The goal is to improve function so individuals become as independent as possible. Companies focusing on medical technology are looking at mechanical devices that can do the work of therapists specializing in limb rehabilitation for stroke patients, thereby freeing therapists to serve more patients. One of these firms is Canadian-based Quanser Inc., and its work in developing haptic robotic technology to create interactive, intelligent devices and software. Working in partnership with the University of Toronto and the Toronto Rehabilitation Institute, Quanser is developing a commercial rehabilitation product for stroke victims — the Autonomous Upper-Limb Stroke Rehabilitation Device, or rehab robot. REPLICATING HANDS-ON THERAPY

Quanser’s device accurately replicates traditional rehab exercises by allowing patients to experience realistic forces and pressures traditionally applied through manual manipulative push-pull therapy that typically occurs in clinics. The rehab robot allows patients to conduct these exercises at home by pushing on the robotic arm, feeling resistance and watching results on a video monitor. The primary challenge in developing

the rehab robot was to provide realistic sensory feedback for the patient, while also enabling the robot to sense how to accurately respond to each patient. Quanser’s autonomous upper-limb stroke rehabiliThe solution was found in tation device consists of three components: the seamlessly integrating hardware robotic platform, the computer that runs the system and a screen to display the required user interface. with an artificial intelligence (A.I.) component. As described by Dr. Alex Mihailidis at the position of the robot. University of Toronto, the system is guided • Think: The current state of the rousing input from the various encoders bot and the previous state of the training located directly on the robot. Each degree allow the artificial intelligence to quickly calculate its next move. of freedom uses a high-quality MicroMo • Act: Once corrective or assistive forces motor that has great haptic specificaare calculated by the A.I., the informations. The encoders are mounted on the tion gets translated into the required motor which allows for high-resolution current for each servomotor to effectively joint position sensing. These positions are display the force back to the patient. then used to monitor the location of the Data from the robotic device is passed patient’s hand and react accordingly within the virtual exercise. to a “state estimator” that shows the state Input from these encoders is used of the patient, such as level of fatigue or ability to reach a target. This determines by the A.I. controller called a partially the progress of the user as a belief state, observable Markov decision process which is a representation of what the A.I. (POMDP), essentially the decisionmaker of the system. It is a typical “sense, controller thinks is going on with the think, act” sequence: patient and the completion of the exer• Sense: The position of the cise. A policy then maps the belief state patient’s hand is measured by utilizing to an action for the system to execute. the high-resolution encoders on each of This can be either setting a new target position and resistance level or stopping the two axes. The encoder information the exercise. is then used to calculate the kinematic

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Robotics

TYPICAL REHAB ROBOT SEQUENCE

• The system makes a decision on the starting point for the patient’s rehab session, including the starting level of resistive force to apply to the patient and the target distance the patient needs to hit. • The system provides a prompt to the patient with respect to the target that needs to be reached. • The patient performs the necessary movement using the robotic platform. • The system collects data from the motion just performed and compares it with the target values. • The system decides the next resistive force and target to be reached. • This process is repeated until the targets are met, or the system decides if the patient has become fatigued and then stops the exercise. Quanser’s team created the physical (robotic) and virtual (rehab simulation) interface between the user and the computer. The robotics stage provides realistic force feedback technology achieved through advanced mechanical design and careful selection of the motors, encoders and other components that are integral to the overall system. For example, motors and transmission ratios were calculated to achieve the required force specs. As with all haptic interface design, special care was taken to ensure the mechanism has low friction and

REHAB R O BOT

minimized inertia, and that it is easy to use. The rehab robot’s real-time control system algorithm was developed and tested using Quanser’s real-time control software and incorporated using the company’s Q4 high-speed I/O data acquisition board that responds to the patient and changes the experiment 1,000 times a second. The third component is the Java interface running a variety of virtual training sessions and communicating with the real-time robotic process via shared memory space. Patients are able to view their progress on a video monitor. An added feature is a software-driven gaming aspect, also displayed, which patients control through motions required during reaching exercises. One example is catching a bunny. Another is a labyrinth where patients move a ball through a maze by manipulating the robotic arm in the required directions. According to Paul Gilbert, Quanser’s CEO, the company is working with rehab institutes to ensure efficacy and affordability of a production-grade system that is portable and easy to use. Commercialization of the rehab robot is expected in 2011. Additional information can be found at http://designnews.hotims.com/ 23128-508. TH REE HAPTIC DEV ELOPMENT TOOLS Quanser’s open-architecture, real-time control development software for accelerated design and implementation

Quanser’s Q8 Hardware in the Loop Control Board

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Quanser’s Power Amplifier

Quanser’s robotic device relies on a real-time control system algorithm using real-time control software. A high-speed DAQ board responds to the user’s input to provide realistic sensory feedback. [ w w w. d es ig n n e ws.c o m]

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Medical Technology ADVERTORIAL

IN THE MARKETPLACE HAYDON KERK’S INTEGRATED STEPPER MOTOR LINEAR ACTUATOR AND CHOPPER  Available in size 17 single or double stack

 TADIRAN’S LITHIUM BATTERY WITHSTANDS -80C Supports medical cold chain Tadiran’s long-life 3.6V lithium thionyl chloride cells are capable of delivering continuous aroundthe-clock power for 20-plus years in temperatures as low as -80C. Currently utilized in data loggers and sensors, these batteries provide reliable power to ensure a continuous data stream to verify that consistent temperatures have been maintained in order to preserve tissue samples, transplant organs and pharmaceuticals that are frozen or packed in dry ice. Batteries modified for the medical cold chain are available in 1/2AA, 2/3AA, AA, C, D and DD cylindrical cells, as well as wafer cells and battery packs. Tadiran http://designnews.hotims. com/23128-502

Haydon Kerk’s MotoDrive™ PDE Captive Linear Actuator is available in size 17 single or double stack and comes with an integrated chopper drive, forming a compact system ideal for precision motion control applications. The MotoDrive system is capable of an output force of 220N (50 lb) for the single stack version and 350N (78 lb) for the double stack version. Haydon Kerk Motion Solutions Inc. http://designnews.hotims.com/23128-503

 KOFORD’S SLOTLESS 22-MM BRUSHLESS MOTORS Available in two- and four-pole designs with Hall sensors or sensorless Koford Engineering’s new line of 22-mm slotless brushless motors offers the highest power density and efficiency in their class. They are available in two- and four-pole designs with Hall sensors or sensorless, with power outputs 0.7 to 430W, speeds from 2,600 up to 201,600 rpm and efficiencies up to 92 percent. Autoclavable and non autoclavable versions are available. Koford Engineering LLC http://designnews.hotims.com/23128-504

THE LEE CO.’S NEW ATOMIZING NOZZLES  Precise atomization in a compact package The Lee Co.’s new atomizing nozzles, available in airless and air-assisted styles, generate a 50-degree hollow cone spray pattern and offer precise, controlled atomization in a compact package. The airless atomizing nozzles do not need an external air supply and will atomize with pressures as low as 15 psi (on water). The air-assisted nozzles utilize an external air source to control the atomization, allowing lower operating pressures (as low as 5 psi). The Lee Co. http://designnews.hotims.com/23128-505

 NEW 2009 MOTION SYSTEMS CATALOG OFFERED BY ANIMATICS ™ CORP. Expanded line of products and peripherals Animatics Corp. has published a new 145-page catalog on its expanded line of motion systems products and peripherals. It includes eight product segments fully detailing SmartMotor™ specifications, fieldbus protocols, brake options, connectivity, peripherals, power supplies, gear heads and software. Also included is an expanded dynamic fold-out selection chart comparing all the different SmartMotor frame sizes and lengths. Animatics™ Corp. http://designnews.hotims.com/23128-506

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Medical Technology

THE ORIGINAL MEDICAL PUSH-PULL CONNECTORS

ADVERTORIAL

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Imagine a cell phone that projects movies and animated graphics directly on to walls—or viewing highresolution, 24-bit color images through helmets or inside goggles. These are a few of the applications made possible through a family of miniature devices called FLCOS microdisplays.

increasing by at least 3X. Compare the two magnified images of fruit at a grocery store in Figure 2.

The basic concept is similar to a tiny back-lit color LCD screen. Most of those screens, however, are covered with a red, blue and green filter mask. When a selected pixel is active (transparent), white light from the backside passes through it and then through one of the color filters; obtaining a full-color image thus requires the light from several adjacent R, G and B pixels to mix and appear as one. There is optical loss through the filters so overall brightness is reduced, and since three or four pixels are needed to build one full-color pixel, effective resolution is reduced to a third or a quarter of the available pixel elements. Because color elements are spread over an area, this is known as spatial color technology.

Cary Eskow is director of LightSpeed, the solid state lighting and Figure 2 – Side by side comparison of spatial (left) and sequential (right) images

Apart from the image quality and color saturation, there are system-level issues to consider as well, such as implementation complexity, power consumption and physical footprint. A new division of Micron called Displaytech is producing sequential color displays fabricated using ferroelectric liquid crystal material, known as FLCOS. FLCOS makes them fast; power consumption is less than 100mW (a fraction of digital micromirror systems) and they operate at low temperatures—a challenge for most LCDs. Their miniature microdisplay panels have integrated image processing circuitry and directly interface to digital video signals in various formats.

LED business unit of Avnet Electronics Marketing. An ardent advocate of energy efficient LED-based illumination, he has worked closely with LED manufacturers, advanced analog IC and secondary optics vendors since his first patent using LEDs was issued two decades ago. LightSpeed works with customers through their national team of illuminationfocused engineers called

Figure 1 – Spatial color achieved with an RGB color mask overlay

“Illumineers,” experienced

A better way to accomplish this is with a sequential color system, using a fast-switching reflective pixel matrix and three high-brightness LEDs (one red, one green and one blue). Instead of a 60 Hz frame rate, the pixels are switched on and off at 360 Hz, in fields. Each field is comprised of only the red, green or blue active pixels; the others are off. During each successive field, one of the three HBLEDs is turned on and one of the three color-corresponding fields is activated (i.e., displayed). When the red HBLED is on, red light is reflected off of the active red pixels, when the green HBLED is on, its light is reflected off of the active green pixels, and so forth. This R-G-B sequence occurs so rapidly that the eye integrates the reflected red, blue and green components into a single highly saturated color. As a result, each individual pixel is bright and full-color (no lossy filters), with the effective image resolution

Figure 3 – The top, underside and relative size of a Displaytech module

Using Displaytech FLCOS modules for heads-up displays, VR glasses, viewfinders, pico-projectors and other applications is straightforward, but some system implementations will require significant optical design expertise. Displaytech has made their products available through Avnet, and I expect to see some very interesting customer applications in the coming months. Data sheets and other product information are now on the LightSpeed website.

in thermal, drive stage and optics design. Prior to LightSpeed, Cary was Avnet’s technical director and managed Avnet’s North American FAE team. To submit questions or ideas, e-mail Cary at LightSpeed@Avnet.com

As always, feel free to send me your questions, comments or inquiries at LightSpeed@Avnet.com Images in Figures 1-3 copyright 2008 Displaytech, Inc. and used with permission

To learn more about designing an LED-based illumination system, go to:

www.em.avnet.com/LightSpeed


FLASH

NEW AND NOTABLE PRODUCT DESIGN

By Terry Costlow, contributing editor 

Conserving electricity is a necessity in anything battery operated. The design engineers who develop portable equipment have to take every step they can to extend battery life as portable products gain use in myriad applications.  BOOKING ON LONG BATTERY LIFE The battle for dominance in the burgeoning digital book market is heating up, putting the spotlight on power management for portable readers. E Ink Corp., which supplies electronic paper displays for many e-readers including Amazon’s Kindle™ and Sony’s Reader, is teaming up with Marvell Technology Group Ltd. to trim power consumption and size. E Ink is using Marvell’s ARMADA 166E application processor, which extends battery life with a zero power hibernation mode. The System-on-Chip also provides a higher level of integration than E Ink had before, helping it make thinner, lighter devices. http://designnews.hotims.com/23129-517



 IT’S WHAT’S INSIDE THAT COUNTS Power consumption is becoming a critical part even for large, specialized systems like nondestructive ultrasonic testing instruments. Dapco Industries Inc. unveiled a tester and is shipping the first one to Union Pacific Railroad, which will use the equipment to peer inside railroad rails. The test system can also be used to examine high-pressure gas cylinders and many other critical metal products. Dapco picked Texas Instruments’ TMS320C6472, a six-core DSP chip, in large part because of its low power consumption. That paves the way for a portable product that’s currently moving toward production, while also reducing heat generation in existing systems. http://designnews.hotims.com/23129-518



 COMMERCIAL VAN PLUGS INTO PARTNERSHIPS Ford Motor Co.’s accelerated electric vehicle strategy will begin bearing fruit next year with the introduction of the battery electric Transit Connect BEV commercial van. Altering the popular European truck for fully electric operation required many close partnerships. Azure Dynamics is providing its proprietary Force Drive battery electric drivetrain, which was tapped in part because of its high power per kilowatt-hour ratings. Azure already provides power trains for some of Ford’s hybrid vehicles. Batteries come from the Johnson Controls-Saft collaboration. http://designnews.hotims.com/23129-519 18


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» designnews.com/sherlock

The Adventure of the Malfunctioning Modem

BY DENNIS COBURN, CONTRIBUTING WRITER Have you applied your deductive reasoning and technical prowess to troubleshoot and solve an engineering mystery that even the fictional Sherlock would find most perplexing? Tell us about it in 600 words and we’ll pay you $100 if we publish your case. E-mail Karen Field at: kfield@reedbusiness.com

At designnews.com: The Instance of the Ruined Radar Relays An engineer investigates the cause of aborted missions. http://designnews. hotims.com/23129-520

Sign up for the newsletter for this blog and get every Sherlock adventure delivered directly to your desktop at http://reg.designnews.com/newsletter/ subscribe.

20

Back when modems were gray plastic boxes that worked at the screaming rate of 300 baud, I was involved in the design and installation of an environmental monitoring system for the U.S. Army Corp of Engineering in Florida. The system was made up of a number of remote monitoring stations housed in fiberglass “coffins,” each consisting of a sensor package, a data recording device and a telemetry link. These packages were placed along a line roughly centered from East to West and running North to South along the length of Florida. The telemetry link included a 300 baud modem at each site connected to standard dial-up phone equipment. Each station was interrogated once a day and transmitted its stored data to a base station for processing. The system was solid in its operation — not having to cope with low temperatures (the recording device was an analog tape recorder converted for digital operation) and featuring its own battery-backed power supply running off of the local mains. However, after a number of months in operation, a problem arose that intermittently prevented the interrogation of some of the remote monitoring stations. By this time I had moved on from the company that was responsible for creation and installation of the system. Since no one was left at the company who knew much about the system, and since I had worked closely with the Army COE personnel during the development, I was called upon to analyze and repair the problem. Conveniently, I had just recently made a decision to quit my job and start my own consulting business. The Army COE contract was just what I needed. I packed up and left New Hampshire for Florida. Upon arriving at the first site of

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three that were malfunctioning, I discovered that the site was fully functional, and I found no way to make it fail. The second site proved to be the same. Whether it was the time of day or just luck, when I reached the third site I found it was still malfunctioning, much to my relief. Every engineer knows that it’s always easier to fix something that’s “broken.” However, the only potential problem source that I could identify seemed to be within the modem. So I tore into it, though I wasn’t really expecting to be able to repair it on site since it was provided by the phone company and I had no information on it at all. Still, I had to act as if I was doing something so I had at it. To my surprise and shock as I pulled the plastic cover off, I had an unpleasant surprise: Half a dozen 2½ -inch-long roaches scurried out of the box! It was then that I discovered both the cause of the problem and why it was intermittent. It turns out that roach feces, when fresh, at least, shorted out some of the modem’s circuitry. Apparently, when dried, depending upon the exact location on which it was deposited, the problem went away. The solution turned out to be pretty simple. I scrubbed the printed circuit board clean, dried it and reinstalled the cover. Then I taped up the entry way the pests had used to enter their favorite toilet. Lesson learned: It’s not always a “bug” in the software or hardware that causes trouble. Sometimes it’s what the bugs leave behind. Dennis Coburn is the owner of Coburn Engineering, an engineering consulting firm based in New Hampshire. You can reach him via our Sherlock Ohms blog comments at www.designnews.com/Sherlock.


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1`SObWdWbg?cOZWbg3f^S`WS\QSÂ&#x2014; ZZZSKLOOLSVSODVWLFVFRP LQIR#SKLOOLSVSODVWLFVFRP  Real life case studies are a click away: www.phillipsplastics.com/case_studies


STORY_ H A R S H WA R D H A N G U P TA , C O N T R I B U T I N G W R I T E R Have you applied your deductive reasoning and technical prowess to troubleshoot and solve an engineering mystery that even the fictional Gearo Wolfe would find most perplexing? Tell us about it in 600 words and we’ll pay you $100 if we publish your case. E-mail Karen Field at: kfield@reedbusiness.com

Gearo

Wolfe

The Adventure of the Typewriter for Heavy Hands M y first job after graduating from IIT Bombay was with the Design Centre of a large Indian company, which among other things like refrigerators, padlocks and forklifts, manufactured manual office typewriters. I joined the typewriter mechanism design group. A new model of the manual typewriter that had been introduced about a year prior to my joining was facing a lot of flak in the market for having an inordinately “heavy” touch. It was tiring out the typist very quickly, compared to the company’s previous models, and those from other competitors — who were rubbing their hands in glee! Quite a few changes had been made over the previous model in one go, and the entire production, quality and design teams were at their wits’ end as to which of those changes had caused it. All sorts of theories were being bandied about by everyone, some bordering on fantasy, some blaming it on the new generation of young typists as being more delicate than the old warhorses. Our design team’s chief had already begun work on redesigning the 6-bar linkage of the typing keys to a more efficient 8-bar linkage system. Having shown some spark as a design engineer, I was asked if I could bring some insight into the problem. The company had an internal standard for “good impression.” I then hunted around for a method or equipment to quantify the energy required to make that standard impression, but found none. So I devised a simple rig — a guided 0.2 kg weight falling from an adjustable height over a chosen key — and now I could measure and tabulate the potential energy required for creating a standard impression. Tests conducted with this simple device on various typewriters, including the old model, produced some startling data. Our new machine consumed three times the energy of its nearest rival, which was the old model. All competitors’ machines were more efficient than ours. The crucial parameter was not the 22

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force, but the energy required to type. Forces were comparable; energy consumed in our machine was much more. Here was the quantified proof! Now came the interesting part: Whodunit? Taking a cue from how IC engines are tested for their internal energy consumption, I started with removing the peripherals one by one: the ink ribbon feeder, the ribbon throw mechanism, the escapement to move the carriage … and repeated the impression test at each stage. I quickly found two culprits: The new ribbon advance consumed about 20 percent of the excess energy and the new universal bar consumed the remaining 80 percent! Here was the culprit! The universal bar is a rod placed below and across all the key levers, so if any letter or the space bar is pressed, this bar gets pressed down too. Its motion drives the ribbon advance, ribbon throw and carriage escapement. This bar is held up against the levers with a pair of springs. In the older design, the key levers and the universal bar were pivoted on the same axis, so there was no relative motion between the two when a key was pressed. In the new design, the axis of the universal bar had been shifted some distance away, and the key pivot, bar pivot and the contact point made up an almost equilateral triangle. So each pressing of any key made the top of the bar rub along the bottom of the key, and this sliding motion under the normal force of the springs consumed the energy. The solution was obvious — move the pivot back to where it belonged. That and other improvements were made, always measuring the energy, and we soon matched the competitors’ energy values. Harshwardhan Gupta lives in Pune, India, has a B.Tech from IIT Bombay and runs his own machine design studio. He has designed many world’s firsts in various custom machines. Visit his website at www.neubauplan.com.


We’re always working to understand your business. That’s why we’re changing ours.

Stephanie A. Burns, Ph.D. Chairman, President and CEO Dow Corning Corporation

“A spirit of innovation and passion for solving customer problems has always set Dow Corning apart. So as we enhance our global Dow Corning ® brand, keep counting on us for smart solutions to your biggest challenges. Through our collaborative, proven process, we can deliver custom silicon-based solutions like no one else. And it’s this kind of working partnership that we’re focusing on now more than ever with Dow Corning branded products and services.”

“Your needs for more options and convenience led us to develop the XIAMETER® brand, a more ef¿cient way to buy standard silicones directly. Through this innovative online model, you still get Dow Corning quality and reliability at market-based prices. Now we’ve expanded the XIAMETER brand to offer you more standard silicones, volume alternatives, and the option to order through your distributor. It’s another way we’re changing to give you more options and value.”

See how we’re changing to better meet your needs at dowcorning.com/transform

Dow Corning is a registered trademark of Dow Corning Corporation. We help you invent the future is a trademark of Dow Corning Corporation. XIAMETER is a registered trademark of Dow Corning Corporation. ©2009 Dow Corning Corporation. All rights reserved.


green

Scene

Environmental news engineers can use

BY ROB SPIEGEL, CONTRIBUTING EDITOR

Zipcar Campus Car-Sharing Program Booms Zipcar’s campus car-sharing brief road trips. program has expanded to Zipcar’s program has grown more than 140 campuses 75 percent in the past year, across North America and now serving a total student Great Britain. The program population of 1 million in 25 works by providing green cities. Using data from the cars on a shared basis to uni- Zipcar has expanded its car-sharing EPA, Zipcar estimates its program to 140 campuses worldversity communities where wide, significantly reducing carbon university programs have parking is a problem and car emissions. reduced carbon emissions by ownership is difficult and nearly 56 million lb annually, costly. University students and staff can equivalent to the annual emission of 4,800 passenger vehicles. use shared cars for off-campus errands and LEAD-FREE

Zone

Come to the Lead-Free Zone blog for answers and updates and to exchange ideas with RoHS expert Rob Spiegel at www.design news.com/Lead FreeZoneBlog

STMicro Transmitters Improve Motor Efficiency

STMicroelectronics’ 1200V IGBT Series of power transmitters was created to reduce the environmental impact of daily-use equipment such as home appliances, HVAC systems and industrial machines. The transmitter was designed to minimize two major sources of energy loss — conducting and switching. According to STMicro, the transmitter’s lower switching losses were engineered to allow a higher operating frequency, which in turn permits smaller and lower-cost components to power-control circuits. Its compact, industry-standard TO-247 package is intended to save component count by integrating the ultra-fast freewheeling diode required by most circuits. The IGBT was also designed to survive short circuits lasting up to 10 μsec, making them STMicro’s IGBT Series was resistant to common causes of created to help improve motor-controller failures such motor reliability and cut down as an error in the gate drive on the cost of repairs and replacement parts. signal, shorting at grounding and breakdown of motor

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phases-to-phase insulation. The goal is to improve motor reliability and save on repair and replacement costs.

San Francisco Tests Wave Energy BioPower Systems of Australia — a wave power company — has partnered with the City of San Francisco to investigate the generation of wave energy from the Pacific Ocean to light homes there. BioPower will work with the San Francisco Utilities Commission to assess the feasibility of a project located five miles off San Francisco’s western beaches. The project will consider installing a wave farm that can generate between 10 and 100 MW. BioPower’s BioWAVET system is designed to supply utility-scale, grid-connected renewable energy while being out of view and without affecting marine life. The system sways in time with the forces of the ocean and streamlines when extreme conditions prevail. Multiple BioWAVET devices, each with a capacity of 1 MW, would be installed as an undersea wave energy farm with the combined power output supply to the on-land grid via subsea cable.


Tempered for scorching heat and windchill factors

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Designing steel rolling mills and wind turbines both raise similar challenges. These applications are subject to extreme operating conditions. And both call for maximum uptime matched with minimal maintenance. With SKF Explorerâ&#x201E;˘ bearings, these demands can easily be met. Combined with SKF lubrication and sealing solutions, condition monitoring and service programmes, uptime can be extended even further. SKF Explorer is a performance class of bearings that has redefined the limits for rolling bearings. Service life and reliability are increased. Noise and vibration levels, friction and heat generation are substantially reduced and wear-resistance improved. With its higher dynamic load carrying capacity, SKF Explorer bearings also helps reduce environmental impact by allowing downsizing which lowers both lubricant and fuel consumption. To find out more, please visit www.skfusa.com.

The Power of Knowledge Engineering

www.skfusa.com


T I Pfrom S

TITUS

Unbelievably useful info on data measurement, collection and analysis from the test expert

JON TITUS CONTRIBUTING WRITER

Look Deeper at Shielding AFTER WRITING LAST MONTH’S COLUMN, “AN UPDATE

Noise Voltage (Vn)

on Shielding,” (DN 11.09, http://designnews. hotims.com/23129-521), I dug further and found the Audio Engineering Society AES48Jon Titus, a former 2005 standard that covers grounding and designer and chief electromagnetic compatibility (EMC). The editor of EDN and standard stresses the need to properly shield Test & Measurement cables to reduce coupling with noise sources. World magazines, It says in part, “the shield contact and the remembers when shell of the equipment connector shall have “fast” signals opera dc connection to the shielding enclosure ated at 10 MHz and via the lowest impedance path possible.” programs came on The AES strongly recommends designers paper tape. make this connection to the outside of the chassis or shielding enclosure. If a design lacks a shielded enclosure, run all grounds to a single ground point via low-impedance connections. Magnetic Shielding Is The 11-page Ineffective at Low Frequencies AES standard provides more Theoretical Shield Voltage (Vs) useful shielding information and examples of what 3dB 0.98 Vs not to do. I also contacted Henry W. Ott, an EMC consultant and author of Effective a text on EMC, Actual Vs Magnetic to ask for his Shielding thoughts about cable shielding. 5fc fc He explained a grounded shield Log of Angular Frequency protects against The voltage electrical fields, and grounding at one end induced on a prevents 60- or 50-Hz currents from flowing shield by a magin the shield and possibly coupling to the netic field drops rapidly below five shielded signals. According to Ott, this type times the shield’s of single-point shield grounding should occur cutoff frequency at the signal source end, because that ground (fc), which you is the reference for the signal. But if the can calculate source “floats” and has no ground connecfrom shield tion, ground the shield at the instrument end. characteristics. Ott notes that a shield, even one grounded

26

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at both ends, provides no magnetic-field shielding at low frequencies. To shield signal wires from high-frequency magnetic fields, Ott recommends grounding the shield at both ends. This type of shield grounding at both ends lets a magnetically induced current from the ambient noise source flow in the nonmagnetic (copper, aluminum, etc.) shield and return through a ground path. That current flow cancels the noise magnetically induced on the shielded signal conductors. Thus you want as low a resistance as possible in the ground loop. In fact, the amount of magnetically induced noise on a shielded signal is directly proportional to the shield resistance. Thus, you want a low-resistance shield. A shielded cable has a shield cutoff frequency (fc) (usually in the audio frequency band) below which the magnetic-field protection drops off quickly. At 5fc, the drop is about 2 percent, which means that below about 5fc the shield protects against electric fields only. According to Ott, shielded cables longer than 1/20th wavelength and with the shield grounded at only one end can act as efficient antennas. So, most shielded cables used above audio frequencies, as well as many used at or below audio frequencies, should have their shield grounded at both ends. The primary reason for grounding shields at both ends is to provide magnetic field protection. This protection only occurs at frequencies above the audio range. For More

REFERENCES

information

1. “AES Standard on Interconnections — Grounding and EMC Practices,” AES48-2005. Audio Engineering Society: http://designnews.hotims.com/23129-522 2. Ott, Henry W., “Electromagnetic Compatibility Engineering,” John Wiley & Sons, 2009. ISBN: 978-0-470-18930-6: http://designnews.hotims.com/23129-523


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Awash in Data

But don’t make it the new political weapon of the information age

W

ith a shiny new emphasis on Let me share an even simpler example of this hard data made possible by the phenomenon. The so-called nation’s report card IT revolution, public policy was issued in October. Nationally, less than 40 now has the potential to become percent of fourth- and eighth-graders demonmore rigorous and apolitical. Sadly, we find strated proficiency at mathematics — dismal news again and again that data seems to be just as po- for the leading technology country in the world. litical as the partisan opinions that have always Well, apparently I must have missed something, fed policy debates. We are indeed awash in data because the headline on my own state education — but are we any wiser? agency’s website reads, “Texas students shine on Just take the tech world’s ever-recurring NAEP math test.” The basis for the cheerleading? hot button issue: “Do we really have enough As poorly as my state performed, it was happily engineers and scientists?” This imporbetter than 40 other states. There’s some tant policy issue lingers on without a bragging rights when our kids’ education definitive answer because the variables is at stake! are so multidimensional that in the To compound matters, we just hands of a good analyst the data can learned from a new study entitled provide ammunition to just about any“Steady as She Goes? Three Generaone with a strong viewpoint. tions of Students Through the Science A case in point: the National Acadand Engineering Pipeline,” by researchGeoffrey C. Orsak ers from Rutgers and Georgetown, that emy of Engineering’s twin studies entitled “The Gathering Storm” and “Is top students in engineering and science are deAmerica Falling off the Flat Earth?” are some of fecting to other majors. The old adage of “look the clearest and deeply analytical works on the to your left, look to your right ...” still applies, subject of the engineering but it is increasingly the case that the kids who pipeline and global comleave aren’t getting washed out; they are actually “We should be ever petitiveness. The studies among the most able in our engineering classes. mindful to not let our not only make the case that So, what do we make of all these numbers and own agendas determine we are facing a shortage of competing reports? I’m reminded of the debate the truth hidden inside information age workers, over global warming where science was used as the piles of reports but more importantly, a surrogate for a deeply partisan fight driven available today.” those we are producing to- primarily by economics and ideology. I am heartday don’t necessarily have ened that the same temperature has not yet been the skills that will be important in the future. reached in the engineering workforce debate. Case closed, or so it would seem. However we should be ever mindful to not let Apparently not. In “What Engineering Shortour own agendas determine the truth hidden age?” — published in Tau Beta Pi’s summer maga- inside the piles of reports available today. Let’s not make data the new political weapon of the zine — Alan Brown makes the argument that we information age. actually have a strong supply of engineers in this country. The crux of his argument is economic Geoffrey C. Orsak is Dean of the SMU Lyle and simple — if there was a real shortage, we School of Engineering. He can be reached at would see skyrocketing salaries. Sounds reasondean@lyle.smu.edu. able (if not somewhat hopeful). 28

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Enter xx at www.edn.com/info


INSIDE NEWS 36

Electronics

37

Materials & Fastening

38

Motion Control & Power Transmission

39

Design Tools

TRENDS BREAKTHROUGHS DEVELOPMENTS

NEWS

» ELECTRONICS THE HALL EFFECT Micromem’s Miniature Hall Cross sensors capitalize on high magnetic sensitivity. Page 36

» MATERIALS XEROX SPREADS ITS INK Using a new conductive silver ink, Xerox says electronic circuits can be directly printed on flexible or rigid plastic surfaces, shortcutting a requirement for silicon semiconductors. Page 37

» MOTION CONTROL ROCKWELL AUTOMATION FAIR Rockwell engineers discussed the benefits of a multidisciplinary approach to machine design during its recent automation fair. Page 38

Source: Oxford University and the University of New South Wales, Sidney, Australia

A tethered desert locust is subjected to smoke derived from heated Johnson®’s baby oil. The smoke was injected into a 3.3 ms-1 wind velocity generated by the wind tunnel. The body angle of the insect was set to 9 degrees, the optimum angle for long distance travel. This data, obtained with a high-speed Photron APX camera, validated the numerical data developed using the CFD tool. Watch video of the tethered desert locust at http://designnews.hotims.com/23129-524. A E R O S PA C E

» DESIGN TOOLS CAD-LIKE MULTIPHYSICS COMSOL Multiphysics Version 4.0 borrows from the CAD tool users interface to put multiphysics simulation within the reach of mainstream engineers. Page 39

Do Bio-Mechanics Hold the Key to Micro-Robot Flight? High-speed photography and computational fluid dynamics may allow engineers to emulate nature in flying micro-robots By John Loughmiller, contributing editor

Now, a little more than a century into the realm of powered flight, the door to natural flight and micro-robot duplication of bio-mechanical processes is opening a bit thanks to fascinating research into the flight dynamics of dragonflies, bumblebees and the desert locust. Consider the dragonfly: It’s fast, can change direction seemingly without effort, and can hover in an extremely stable manner. How can it do these things, and just as important from a research standpoint, why does it do these things? The why is to help it capture prey and avoid becoming prey. Less capable flyers, like mosquitoes and other small insects, are no match for its superior flying skills. And few birds, the dragonfly’s principle enemy, can compete. When the dragonfly sees doom approaching, it simply darts off to one side at the last moment, leaving the bird nothing D E S I G N N E W S D E C E M B E R 2 0 0 9 [ w w w. d e s i g n n e w s . c o m ] 3 1


N EWS AE RO SPAC E , C on t i n u e d

but empty air where it thought its next meal would be. But it’s the how of the aerobatic performance that takes a little getting used to. Z. Jane Wang is a professor of theoretical and applied mechanics at Cornell University who has done landmark research into the flight dynamics of the dragonfly. In an interview posted on Cornell’s Chronicle website, Wang says, “Dragonflies have a very odd stroke. It’s an upand-down stroke instead of a back-and-forth stroke. Dragonflies are one of the most maneuverable insects, so if they’re doing that they’re probably doing it for a reason.” “A dragonfly uses a lot of aerodynamic drag to carry its weight. That is weird,

because with airplanes you always think about minimizing drag. You never think about using drag,” Wang continues. When the dragonfly is moving forward, the two sets of wings are flapped in phase, generating lift and directional momentum. When hovering, however, the rear wings are intentionally flapped out of phase with both the angle of attack and relative position of the front wings which generates drag, preventing motion relative to the earth, but still generating lift. By decoupling one rear wing’s movement from the other, the insect can also move side to side. If these motions can be duplicated mechanically, they

could give a micro-robot the ability to move rapidly from one location to another and then hover for purposes of surveillance. All the while the micro-robot would be generating an extremely small visual and radar footprint, plus an equally small noise signature. Bumblebees Can Fly

Richard Bomphrey and Adrian Thomas, zoology professors at England’s Oxford University, have learned that brute force is enough to overcome all sorts of aerodynamic taboos associated with levitating a large object using small lifting surfaces. Their research determined that the bumblebee’s huge thorax, with its intrinsic muscle mass, plus energy-rich

nectar used for fuel, make up for an inefficient flying style. The Oxford duo also found that it’s as if the insect is split in half. Not only do its left and right wings flap independently, but the airflow around them never joins up to help it slip through the air more easily. Bomphrey says such an extreme aerodynamic separation between left and right wing is very unusual and adds to the insect’s inefficiency. But the bumblebee’s inefficiencies are not without a human flight counterpart: Every time NASA launches the space shuttle, enormous quantities of energy are expended for a relatively small payload. The bumblebee’s idiosyncrasies may eventually turn out to be useful in the


AE RO SPAC E , C on t i n u e d

robotic world, but for those trying to create an efficiency leap by use of bio-mechanical flight methods, better just give the bumblebee an award for unusual design approach and move on. The Year of the Locust

Ever since Biblical times, hoards of desert locusts have flown intercontinental distances non-stop for one purpose: to strip the vegetation bare, convert it to energy, and move on to the next victim. Engineers working on microrobots intended to stay aloft for long periods should be interested in recently published research into the locust’s bio-mechanics. John Young, a scientist with the University of New

South Wales, Australia, teamed up with Bomphrey and Thomas to try and unlock the locust’s secrets. In their research paper, “Details of Insect Wing Design and Deformation Enhance Aerodynamic Function and Flight Efficiency,” the men reported how they mapped the wing surface geometry of the locust using Gambit 2.4.6, a commercial meshing tool. More than 24,000 cells were mapped on the forewing, hindwing and the body. Kinematics were obtained using four highspeed digital cameras recording the deforming surface topography of the wings while the locust was tethered in a wind tunnel at its optimum long distance flight angle.

Source: Wikimedia Commons

N EWS

The dragonfly’s two front wings are in a stable position in this still frame and appear to be generating equal lift. The two back wings, however, do not match the position of the front wings nor do they match positions relative to one another. It appears this dragonfly is about to execute a lateral maneuver from a hover by inducing drag with the rear wings in unequal amounts. The resulting complex vortices being generated can only be analyzed using computational fluid dynamics.

The unsteady, incompressible Navier Stokes equations were solved using another commercial software package, Fluent 6.2.16. Gambit’s dynamic mesh feature was used to create a moving boundary layer mesh so that wing movement, microscopic wing surface deformations

and body interaction could be tracked throughout the wing beat cycles. When the simulations were run, they closely matched results obtained by injecting smoke into the wind tunnel’s air stream as the locust flapped its wings. The researchers achieved full fidelity modeling of


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the complex structure and movement of the locust’s wings for the first time. Using Gambit and Fluent CFD tools, Young, Bomphrey and Thomas proved that the locust has mastered the art of minimizing airflow separation on the wing’s leading edge and controlling vortices on the trailing edge — twin efforts necessary for long distance, low-energy flight. The locust’s dynamic changing of the angle of attack during the wing beats seems to be another key to success. But the researchers have found something else: The multitude of veins and individual cells that make up the wing structure are being deformed during the flapping of the wings. The types and magnitude of deformation depends on the task being executed. The resulting changes in the shape and smoothness of the lifting surface have a direct effect on the efficiency of the airfoil and represent one of the most difficult challenges for engineers trying to duplicate the locust’s amazing efficiency. The Road Less Traveled

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N EWS

There’s a good reason why powered human flight has evolved the way it has: It’s extremely tough to emulate natural flight mechanically. First, the stresses involved in accelerating, stopping and reversing the motion of a mechanical wing will cause a great deal of wear on the components. In a bio-mechanical system, the body simply replaces cells when they are damaged. Mechanical actuators also eventually wear out, but a damaged muscle will simply heal in an insect or bird. To solve these problems,

there will either need to be a breakthrough in component longevity or a mechanical insect will need to become self-repairing in a dynamic environment. There’s yet another aspect to consider which seems paradoxical at first glance: The lifetime for many insects is measured in weeks which is one reason evolution has selected the bio-mechanical methodologies it has. The paradox is the MTBF of an insect’s component parts is excellent because it’s limited by the finite lifetime of the creature itself. What will be considered an acceptable lifetime for a mechanical insect? Will it also be measured in weeks? Then there’s the control side of the equation. Because there are twisting motions, linear motions and deforming motions that vary with wing position and task, some sort of feedback network would have to be integrated into the flight surfaces and these data would have to be assimilated by computers programmed to provide three-dimensional wing geometry control as part of a complex feedback loop. All of this increases weight, and since the first use for this technology would appear to be flying micro-robots used for surveillance, operational weight adds significant complications because of the need for a payload that would support a camera and a signal transmission system. At the end of the day though, federal and local governments, as well as private industry, are very interested in the potential of bio-mechanics as a way to implement flying microrobots. As a result, large amounts of money will likely be made available to solve these problems.


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» ELECTRONICS

New Horizons for Hall Sensors Miniature Hall Cross sensors capitalize on very high magnetic sensitivity

By Al Presher, contributing editor The Hall Effect was discovered by Dr. Edwin Hall in 1879 and is used in everyday applications such as proximity switches, positioning, speed detection and current sensing. But now Hall Cross sensor technology innovation is making a comeback with miniature, printable Hall sensor arrays that offer concentrated sensitivity and open up new application areas. What makes the design of Hall Cross sensors from Micromem Inc. unique is an ability to provide very high magnetic sensitivity while at the same time increasing device density, reducing cost and simplifying manufacturing complexity. The design features a gallium arsenide (GaAs) substrate that optimizes sensitivity with cost and overall device size, and provides much higher electron mobility (sensitivity) than silicon and resistance to temperature drift due to a higher energy band gap. “Magnetic Hall sensor principles are

essentially a physical effect that happens in materials that are carrying current in a magnetic field,” says Steve Van Fleet, president of Micromem. “If you have a magnet and a Hall sensor, and pass bias current into a magnetic field, it will deflect the signal depending on the direction of the magnet. It is very sensitive to a magnetic field, and basically the current output can be used to determine the strength of the magnetic field.” A key innovation in the Micromem technology is an ability to array the Hall sensors to significantly reduce the signalto-noise ratio. “While everything in the past has been integrated circuits and chips put onto a PCB board, we now have custom arraying and are actually dissolving them into gallium arsenide ink and using three-dimensional statistical manufacturing,” Van Fleet says. “We have made a very, very small sensor and are using proprietary epilayer gallium

Micromem’s Hall Cross sensor design features a gallium arsenide substrate that optimizes enhanced sensitivity to magnetic fields with cost and overall device size.

arsenide to create a Hall sensor with concentrated sensitivity,” Van Fleet says. He says Micromem is partnering with Nano Opto and using a process called atomic layer deposition (ALD) to basically lay down one molecule at a time to design a concentrator. Because the ALD process is extremely smooth, they have been able to do magnetic modeling and develop an optimum shape to collect magnetic energy in very weak magnetic fields. “Our focus is to go after new and unmet needs,” says Van Fleet. “What we have found is that we can build cost-efficient sensors because, on a 6-inch wafer we get several hundred thousand of these, the cost of the sensors is micro pennies. Arrays open up a whole new opportunity for sensing technology.”

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Âť MATERIALS

New Xerox Ink May Shake up Electronics Manufacturing

Conductive ink can be printed on ďŹ&#x201A;exible ďŹ lm or moldings to embed electronic circuits.

Electronics can be easily incorporated in three-dimensional plastic parts for auto and other applications

By Doug Smock, contributing editor, materials and fastening A new Xerox technology could significantly expand applications for three-dimensional electronics components. The company developed a conductive silver ink that creates a low-cost method to add computing power to plastic and other surfaces. One potential application is a â&#x20AC;&#x153;smartâ&#x20AC;? pill box that tracks how much medication a patient has taken. There are also significant opportunities in automotive applications where electronics could be embedded into plastic structures, a long-sought technology. â&#x20AC;&#x153;For years, thereâ&#x20AC;&#x2122;s been a global race to find a low-cost way to manufacture plastic circuits,â&#x20AC;? says Paul Smith, laboratory manager, Xerox Research Centre of Canada. â&#x20AC;&#x153;Weâ&#x20AC;&#x2122;ve found the silver bullet that could make things like electronic clothing and inexpensive games a reality today. This breakthrough means the industry now has the capability to print electronics on a wider range of materials and at a lower cost.â&#x20AC;? Integrated circuits are made up of three components â&#x20AC;&#x201D; a semiconductor, conductor and a dielectric element. The new silver ink from Xerox is said to provide all three of the materials necessary for printing plastic circuits. Molecules precisely align themselves in the best configuration to conduct electricity in the ink formulation. â&#x20AC;&#x153;We will be able to print circuits in almost any size from smaller custom-sized circuits to larger formats such as wider rolls of plastic sheets â&#x20AC;&#x201D; unheard of in todayâ&#x20AC;&#x2122;s silicon-wafer industry,â&#x20AC;? says Hadi Mahabadi, vice president and center manager of Xerox Research Centre Canada. â&#x20AC;&#x153;We are taking this technology to product developers to enable them to design tomorrowâ&#x20AC;&#x2122;s uses for printable electronics.â&#x20AC;? One of the technical breakthroughs was development of a conductive ink with a melting point below that of plastic. The silver ink has a melting point of 140C, compared to 267C for polycarbonate, which is widely used for computer housings. Melting points for commodity plastics, such as polyethylene, are much lower and would not be used with the new inks. With the Xerox ink, circuits can be printed just like a continuous feed document without the clean room facilities required in current chip manufacturing.

Source: Xerox

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» MOTION CONTROL

Rockwell Extends Multidisciplinary Design Tools New software interoperability aimed at reducing cycle times

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vices from Rockwell and its partners. One theme Rockwell hoped to get across to the engineers who swarmed the aisles was the benefits of a multidisci-

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plinary approach to machine design and the tools it has developed to help facilitate a more integrated design environment. “One of the things we recognized in the past was that mechanical, electrical, controls and software engineers worked on their part of the design. Then they threw it over the wall,” said Michael Burrows, director of marketing development for Integrated Architecture. When the process works that way, according to Frank Kulaszewicz, vice president and general manager, Control Visualization Business, the design cycle is inefficient, with an over-reliance on physical prototypes to prove whether the design actually works. “It’s an expensive and time-consuming way to engineer a system, and it’s difficult to optimize the design as a whole. Another side effect is that engineers tend to over-design their aspect of the system,” he said. The idea of one design tool — in Rockwell’s case the RSLogix 5000 control system and configuration software — with interoperability with software such as CAD and a library of specific toolkits for functions such as motion control and process control, said Burrows, creates an immediate efficiency with less of a learning curve. Building upon this philosophy, Rockwell continues to extend its offerings. Noteworthy is the update to its Motion Analyzer Software, which engineers use to create a mathematical model to size and select an optimized motion system, which now provides interoperability with SolidWorks 3-D CAD software. This new capability allows users to create a profile in Motion Analyzer and visualize it in SolidWorks. Significantly, the motion profiles from Motion Analyzer can now be exported directly to the RSLogix 5000 programming software. “Engineers can now take the digital design of the motion system and add the controls and electrical to it faster and with less programming,” said Victor Swint, vice president and general manager, Motion Control Business. “Now the companies who have been saying that they cannot optimize their designs really can.” Read more from the Rockwell Automation Fair at designnews.com: • “Rockwell’s ‘Essential Components’ Program Speeds Design Cycle”: http://designnews.hotims.com/23129-525 • “MTS Linear Position Sensor Extends Performance”: http://designnews.hotims.com/23129-526


» DESIGN TOOLS

COMSOL Makes Multiphysics More CAD-Like Version 4.0 upgrade boasts Model Builder graphical programming tools, new user interface

By Beth Stackpole, contributing editor, design tools Aiming to put multiphysics simulation capabilities within reach of mainstream engineers and scientists, COMSOL has completely revamped COMSOL Multiphysics with a new user interface that takes a page from CAD tools. The centerpiece of the new COMSOL Multiphysics Version 4.0, due out by the end of the year, is Model Builder, a set of graphical programming tools that guide users from model creation to simulation results, while providing full control and oversight of their simulation tasks. Via its dynamic model configuration approach, users can build a model in the new environment by right-clicking to perform such tasks as importing CAD geometries, meshing, specifying specific materials properties, solving and plotting results. Despite growing recognition of the importance of early simulation as part of the product design process, many engineers still don’t have access to sophisticated multiphysics simulation capabilities, due primarily to the complexity of the offerings. “(With Version 4.0), if you know CAD, you know our tool,” says John Dunec, COMSOL’s vice president of sales. Philippe Masson, senior scientist with Advanced Magnet Lab and a long-time user of COMSOL Multiphysics, says Version 4.0’s new usability features will undoubtedly make the tool more accessible to engineers, especially those not that familiar with physics. “People get scared when there’s too much physics involved,” says Masson, who uses COMSOL Multiphysics for electro-thermal simulations of one-of-a-kind magnets used in physics and medical applications, among other uses. Along with the interface improvements, Version 4.0 supports expanded CAD interoperability with the new LiveLink for PTC Pro/ENGINEER, a tool that creates a seamless connection between the two environments. As a result, engineers can change a feature in a Pro/ENGINEER CAD model and have it automatically update the geometry in COMSOL Multiphysics, while retaining physics settings. There are versions of LiveLink already available for SolidWorks and Autodesk Inventor. Go to www.comsol.com for Multiphysics tutorials, webinars and applications.

Users perform the entire model setup — from geometry creation to visualization of the simulation results — in Model Builder in COMSOL Multiphysics Version 4.0.

39


COVER STORY

STORY_KAREN FIELD, EDITORIAL DIRECTOR IMAGE_PAVAN GROUP

The

Spaghetti

R

Wars

Two Italian manufacturers of dry pasta-making machines now dominate an exploding market. They got here by taking very different approaches to working the fundamentals of heat, mass and momentum transfer principles.

igatoni. Lasagne. Ziti. Bucatini. Rotelle. At 28 kg per person per year, Italians love their pasta, and they still reign as the top consumers of it today. But the rest of the world is aggressively playing catch up. Worldwide production nearly doubled between 1998 and 2006, from 6.4 to 11.7 million tons. Last year, dozens of high-capacity, dry pasta equipment lines were installed around the globe in countries as diverse as Hungary, South Africa, Saudi Arabia and Guatemala. These lines operate 24 hours a day for weeks on end, without interruption. Since pasta is practically in the DNA of Italians, it may come as no surprise that two Italian companies, FAVA S.p.A. and Pavan Group, own two-thirds of this rapidly expanding, $270M global market. In fact, they are practically next-door-neighbors in a region of Northern Italy with a long history and high concentration of skilled manufacturers of equipment for specific industries â&#x20AC;&#x201D; from pasta to packaging. The fascinating part of the story is how these two companies, both founded before 1950, came to dominate the market through the novel application of basic engineering principles and the ability to evolve and change in order to meet the demands of an industry in transition. Consider that just 30 years ago, there were 1,000 pasta producers in Italy. That number has fallen by an order of magnitude to just 100 companies today. This consolidation has led to growing demand for bigger plants with higher capacities and equipment with shorter cycle times and higher throughput. Meanwhile, the end product must continue to meet high customer expectations.

40

D E S I G N N E W S D E C E M B E R 2 0 0 9 [ w w w. d e s i g n n e w s . c o m ]


Pavan’s Drying Process T oC

120

Air Temperature C and RH%

100

S1 A2

80

A2

S2

A2

S2

P.M.%

30

S2

25 20

60 15 40

10

20

5 0

0 0

0.5

1.0

1.5 Time (Hours)

2.0

2.5

3.0

Source: Pavan Group

To achieve a high-quality end product, Pavan’s drying process, shown here for short cut pasta, alternates a series of drying (A1, A2) and stabilizing or annealing (S1, S2) steps, in which a wide range of temperature and air humidity values can be obtained.

Source: Pavan Group

Over the past 70 years, the process of making pasta has evolved dramatically — from small, handmade batches of pasta cooked fresh to today’s high-tech, high-throughput machines designed to pump out anywhere from 500 to 6,000 kg/h for long and short cut pasta. “It’s a convenience food that is cheap, easy to store and easy to prepare,” says Luigi Fava, managing director and general manager of FAVA S.p.A, describing the reasons behind the growing market demand for dry pasta. A third-generation Fava involved in the family business, which was founded in 1937 and has sold more than 2,250 pasta lines since, he’s excited about the future. “Out of almost 7 billion people in the world, less than 1 billion eat pasta today. In a way you could call it a new food,” he enthuses. At 64 years old, Fava’s main Italian competitor, Pavan Group, describes itself as “the youngest” of the three major competitors (the third is a Swiss company). Dr. Luca Zocca, Pavan’s corporate marketing manager, is no less upbeat about the future. “Pasta has considerable potential in large countries such as the U.S., where the per capita consumption today is just 10 kg per person per year,” he says. He notes that the Atkins Diet, legendary for shunning carbs, “pretty much crippled” the U.S. market five years ago. But sales are roaring back, enough so that Barilla recently opened a plant here with a 60,000 ton capacity. The goal of a dry pasta machine is to produce an end product with a moisture content of 12 percent, a figure mandated by legislation. At this level, the water activity is sufficiently low to

35

R.H. %

A1

Pasta Moisture %

From Small to Large Batches

guarantee no growth of microorganisms, while the finished product will retain its shape. While on the one hand it might seem to be a fairly straightforward process, the exact thermal conditions to which the pasta is subjected during the drying phase have an impact on its structure and porosity, which in turn affects its mechanical strength and texture during cooking. Four basic parameters influDry pasta samples are ence pasta quality: Processing evaluated at Pavan’s lab at temperature, humidity and its headquarters in Galliera time, and the residual moisture Veneta, Italy. gradient in the final product. As engineers seek to strike the right balance in their process to achieve the highest quality final product, drying cycles are getting more sophisticated. And here’s where FAVA and Pavan have been particularly innovative in their approach.

Source: Pavan Group

Drying: A Complex Process

A modern, multi-million-dollar dry pasta production line consists of a mixer/extruder, pre-dryer, dryer, cooler and packager. Capacities have been consistently growing, with examples like this new Barilla facility in the U.S. pumping out 60,000 tons of finished product per year.

A typical, modern production line consists of five main process components — a mixer/extruder, pre-dryer, dryer, cooler and packager. The pre-drying and drying sections represent the most complex and biggest chunk of the cost (around 65 percent) of these multi-million dollar machines. With inside temperatures reaching upwards of 100C (and high relative humidity), the components must be carefully engineered to sustain the thermal expansions generated by the temperature change. Traditionally, pasta was dried at temperatures less than 50C for long periods of time — 20 to 30 hours. Over the past two decades, the industry has gradually taken temperatures up to around 100C, which has had a significant impact on processing time. Current drying cycles range from five to six hours for long pasta — a number everyone agrees is close to the limit. “Drying cycles at low temperatures, at high temperatures, and at ultra-high temperatures and the advantages of each type of cycle have all been discussed for a long time,” says » D E S I G N N E W S D E C E M B E R 2 0 0 9 [ w w w. d e s i g n n e w s . c o m ] 4 1


Fava. “At the end of the 1980s, the race towards applying ultra-high temperatures and short drying cycles was being proposed as the ideal solution by some of the competitors. However, results demonstrated that top-quality pasta is not done in ‘a hurry,’ and there is no advantage in promoting fast drying cycles at ultra-high temperatures.” Today, Fava says, the correct drying cycle is clear to everybody. That may be so, but engineers at the two companies have taken very different approaches to working the fundamentals of momentum, heat and mass transfer to achieve the final moisture content and optimal cycle time. They’ve even hired academic researchers and technical experts at institutions like the Milan University, the Ministry of Agriculture and the National Research Institute for Food and Nutrition in Rome to weigh in on the science. Two Ways to Heat-Treat the Pasta

Zocca says that Pavan revolutionized the market 20 years ago with a patented drying process that drastically reduces drying time without altering the properties of the pasta. He says his company currently has the fastest drying cycle — five hours — for long cut pasta. In its process, Pavan applies high temperature at the initial phase of the drying process, which it says blocks enzymatic activity (thereby maintaining the nutritive properties) and enhances product color. Because the high temperature quickly decreases the water content, it also reduces processing time to that magic under-six-hours figure. Low air humidity at this stage, they claim, also protects the pasta’s delicate starches from swelling. The pasta then goes through a series of alternating stages of fast-drying and stabilizing — this second step essentially involves remoistening the outer layer of the pasta while holding a constant temperature. Zocca says that this process, basically annealing, eliminates any residual stresses that could lead to cracking in the final product and provides a stable product

Temperature H% Pasta

30

80

20

60 15 40

5 0

Temperature oC

H% Pasta

120 100

25

PreDryer Zone

20 Dryer Zone 50

100

Stabilization Zone 150 200 250 Time (Minutes)

300

350

0 400

Source: FAVA S.p.A.

To achieve a high-quality end product, FAVA’s drying process, shown here for short cut pasta, is based on gradual cooling and a long stabilization period to eliminate any residual stresses.

42

Long cut pasta machines like this are designed to pump out as much as 6,000 kg of pasta per hour.

suitable for immediate packaging. To tightly control the conditions and adjust the variables in each zone and produce pasta with the desired texture and color, the drier is divided into a number of zones with independent controls for air temperature, relative humidity, heat exchanges and exhaust ports. “Our competitive advantage is that our process allows us to take lower grade flours (than durum wheat) and obtain a finished product of higher quality than could be achieved through traditional processes,” says Zocca. FAVA’s technology involves an engineered sequence of operations, which Fava says guarantees maximum drying flexibility and ease of operation. The company’s website also states that the process of gradual cooling and then stabilization represents one of the most important innovations in the production of long pasta. Rather than a series of alternating dryer and stabilizing phases, the process consists of a relatively intense pre-drying phase, followed by a quick-drying cycle of 160 minutes in which the pasta reaches a maximum temperature in a short time. It is then quickly lowered. The third and final stage is the stabilization zone, which brings the pasta to a uniform moisture content to eliminate any stresses. The entire process is tightly controlled by PLCs to produce the desired characteristics in the end product. Continuous Innovation, Overcooked Pasta

FAVA’s Drying Process

12 10

Source: Pavan Group

COVER STORY

D E S I G N N E W S D E C E M B E R 2 0 0 9 [ w w w. d e s i g n n e w s . c o m ]

Though they have chosen to take very different approaches in their process, both companies clearly produce a quality end product — they each own a 35 percent share of the global market and have lines operating in plants all over the world. And they’re not resting on their successes to maintain their dominant position in the future. Both say they are investing a lot of time, energy and resources in R&D to improve the production process and the quality of the product. One thing about these Italians, though, they do tend to be a bit, well, snobbish when it comes to pasta: “It’s overcooked all over the world,” Fava insists. Which makes one wonder why these companies are spending so much engineering time and effort ensuring that a highquality product comes off the end of the line, if we’re all just going to cook our spaghetti until it’s limp. Fava has the answer: “Even an overcooked pasta,” he says, “is better than a badly made one.”


7

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Source: Vidacare Corp.

STORY_CHARLES J. MURRAY, SENIOR TECHNICAL EDITOR, ELEC TRONIC S

Paramedics typically use EZ-IO to infuse fluids into the tibia, near the knee. Here, inventor Larry Miller performs the procedure on a patient.

Anatomy of a

Life Saver Inventor Larry Miller overcame technical issues, patent problems and institutional resistance in the course of creating a successful medical product

N

o one knows how many lives Larry Miller’s drill has saved. Tens of thousands for sure. Maybe hundreds of thousands. But from the first day Miller conjured up the vision for his medical product while attending a standing-room-only funeral in Texas seven years ago, the path to success has never been easy. By most accounts, it should have been a slam-dunk. Miller, an emergency room physician, had an eminently logical idea: To restore fluids in patients who have lost massive amounts of blood during life-threatening

emergencies, he wanted to use the body’s bones. Bones, it seems, transport blood to the heart quickly, just as our veins and arteries do. The difference is that bones don’t collapse when blood pressure plummets. “The vision was, ‘There are thousands of people who are dying because we can’t get into their veins,’” Miller recalls. “So I said, ‘If we can develop a needle and a mechanism to get into their bones, it would save lives and be a big hit.’” In retrospect, Miller’s vision was dead-on. Since he launched Vidacare Corp. in 2001, the company has shipped more than a half-million

needle sets and treated more than 350,000 patients with its hand-operated bone drill. Approximately half the ambulances in the U.S. now employ the technology. In a few years, the company’s annual revenues have climbed to more than $20 million. Moreover, Vidacare is moving into a new medical arena this month by launching a drill that will take much of the pain out of bone biopsies for cancer patients. For engineers, though, the real story of Miller’s success is one of persistence. During the past seven years, Miller’s product has become a monument to the kind of staying power that’s needed by every wouldbe inventor. In the course of achieving success, Miller tried nail guns and drills, worked with thousands of cadaver bones, tested more than 100 needle tip designs, struggled with patent problems, hunted for funding and battled institutional indifference, before finally realizing some measure of success. “It was astronomically difficult getting this accepted,” says Scotty Bolleter, a flight paramedic for San Antonio AirLife and a nationally known educator familiar with the technology. “It’s always very, very difficult gaining acceptance in the medical industry, and this technology was no exception.” Tragic Inspiration

Miller’s journey began after a friend and paramedic, Nick Davila, died in an auto accident. At the scene of the crash, ground paramedics tried desperately to start intravenous (IV) fluids, sticking Davila unsuccessfully nearly 20 times before he fell into cardiac arrest. Although paramedics say Davila’s death

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»


BONE DRILL

Source: Vidacare Corp.

a dynamic flow. I can measure it with a pressure transducer. I can hook up a bone and show you the blood pressure inside it.” Getting “Knocked Down”

Vidacare’s engineering staff tried more than 100 different designs for the needle tip, which must drill into the bone and enable an IV line to be attached.

a few minutes later was not caused by the lack of an IV, the emotional trauma of the event planted the seeds of an idea in Miller’s mind. He was determined to find a more reliable way of administering fluids. “I went to the funeral and there were thousands of people, standing-roomonly,” Miller says. “Standing there, I said, ‘This should never happen.’ It was a moment of truth for me.” Indeed, it was a moment of truth for Miller, largely because he understood from previous experience the value of using bones as a conduit for fluids. A decade earlier, Miller tried to launch a product called Osteoport that administered cancer drugs through a connection to the hip bone or tibia. Although the company never took off, the experience served as a lesson for him. “That’s when I first learned about the capability of bone marrow to transfer drugs and fluids,” Miller says now. Indeed, his experience with Osteoport gave Miller a unique perspective, especially in light of his 30-plus years as an emergency room physician. After years at Chicago’s Cook County Hospital (the hospital where the NBC drama “ER” was set), he had seen victims of virtually every imaginable illness, accident and violent crime, and had struggled countless times to stick IVs into patients whose traumas had caused their veins to collapse. “It’s a cruel law of nature that the worse a patient needs an IV, the harder it is to find the vein,” he says. That’s where Miller’s idea came into play. Although bones had rarely been used to transport fluids, emergency medical technicians and physicians knew that they could do the job. “Coming out of the bone, you find veins, running into bigger and bigger veins,” says flight paramedic Bolleter. “It’s 46

Within days of Davila’s funeral, Miller hooked up with biomechanical engineers in the prototype lab at the University of Texas Health Science Center at San Antonio. There, he began work on the sticky problem of finding a mechanism to deliver fluids to the center of a bone. “We got cadaver bones and started trying different things,” Miller recalls. “We shot the bones with a nail gun. That seemed to be a good idea until one of the engineers shot himself through the finger.” Miller subsequently began working with drills, but learned that when he pulled the drills out of the bone, he couldn’t locate the hole for the IV. He tried putting funnels into the bones, but that didn’t work either. After more than a year of research, a solution emerged. Growing up in Ypsilanti, MI, as the son of an automotive engineer, Miller had been exposed to manufacturing technology. Eventually, his memories from those days kicked in. “I woke up one night and had the answer,” he says. “I remembered my dad had a tiny, hollow, oil-cooled drill. I figured we could use that kind of drill and hook an IV to it.” The hollow drill worked, largely because it provided an avenue for fluid travel. Miller could now keep the drill tip engaged in the hole, while connecting the IV to it. As the design evolved, Miller applied Engineering Advice for Start-ups Turning a crude invention into a successful product takes a strong but simple idea, a will to improve, and a staff that’s willing to do it all, say Vidacare engineers. “I look for resumes that say, ‘I’m really good at one thing, but I can also do a lot of other things,’” says Bob Titkemeyer, senior director of quality assurance and regulatory affairs for Vidacare. A few other suggestions from Titkemeyer and Vidacare founder, Larry Miller: 1. Look for strong manufacturing partners. 2. Be willing to continuously improve your product. 3. Look for ways to expand your market. 4. Look for team players who are willing to share credit for successes. 5. Be open to new ideas from other engineers and customers. 6. Be willing to wear multiple hats.

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for a patent. But here, obstacles appeared. Earlier searches for so-called “intraosseous” infusion products (products that inject fluids into bone marrow) had yielded nothing. But after countless hours of research, patent attorneys told Miller that there was another such product that hadn’t been noticed previously because it spelled intraosseous with a dash (“intra-osseous”) and had therefore evaded earlier computer searches. “When you’re inventing a new product, you have to be ready to get knocked down,” Miller says now. “But when I saw that, I said, ‘No one will ever invest in us now.’” Worse, the patent was about to expire for lack of payment because the owner had given up on the idea. Still, Miller wasn’t ready to quit. He tracked down the patent’s owner, a retired pediatric emergency doctor in Detroit, and traveled to Michigan to visit him. “I said, ‘We don’t have money but I need your patent and I can give you some shares in our company.’ So the patent became ours.” Refining the Design

With the patent reinstated in his name, Miller started looking for funding. But potential investors were dubious. “I took it around to investors and told people I had this little device that looked like a Dremel drill,” Miller says. “I showed them the hollow needle and demonstrated how you could hook an IV to it. But it was too crude. The investors looked at me and said, ‘A Dremel drill won’t work for this.’” Miller still wasn’t giving up, though. Deciding he needed a more refined prototype, Miller traveled to a medical design show in Anaheim, CA and searched for engineering contract firms that could build one for him. He found five companies, mailed out requests for bids, and waited. “One company in Colorado wanted $80,000 and six months to complete it, another wanted $40,000 and three months, a third just wanted to do the CAD drawings,” he recalls. “Finally, a fourth one — BC Tech in Santa Cruz, California — called and said they wanted $14,000 and told me they could do it in two weeks.” Miller chose BC Tech’s bid and, sure enough, had a prototype in hand two weeks later. With the refined prototype, which was about the size of a glue gun and powered by a 9-V battery, he began


Trabeculae

Osteon Periosteum

to attract investors. “It’s amazing how close today’s product is to that first prototype,” Miller says.

Haversian or Central Canal

Source: Scotty Bolleter

Compact Bone

Dealing with Resistance

At that point, though, the real engineering was just beginning. Miller, now teaming with a design engineer and a quality engineer, soon realized his product needed more power to go though bone more efficiently. Over the course of the next year, Miller and the engineering team tried more than 100 different types of needle tips. They learned that minor changes in pitch — as little as 3 degrees — could dramatically affect the torque, as well as the time it took to reach the center of a bone. They tried various hollow tips, including twist drill tips and paddle tips, along with different shapes, angles and materials, including 316 and 304 stainless steels. Ultimately, they settled on a uniquely shaped, hollow 304 stainless-steel tip manufactured by K-Tube Corp., machined in the U.S. then sent outside the country for injection molding of two pieces of the attached hub. In concert with the needle design, Vidacare engineers also developed the drill’s electromechanical driver. The company won’t provide names of vendors or the details of the design, but Miller does say that engineers selected a 30,000-rpm offthe-shelf electric motor and linked it to a planetary gearbox to reduce the speed to about 1,200 rpm. The speed reduction prevents it from getting bogged down and stalling as it bores through a patient’s bone. “We had to have a certain amount of torque and a certain amount of speed to make this drill work,” says Bob Titkemeyer, senior director of quality assurance and regulator affairs for Vidacare. “To find a motor-gearbox that was reliable and that we could afford in high volume — that was a chore in itself.” The U.S. Food and Drug Administration, however, was not impressed by any kind of motor-gearbox. “They told us it was dangerous to put a needle into bone using a powered device,” Miller says. “We had to do studies showing it was actually safer using power.” After FDA approval in 2004, there was still skepticism. Many in the medical community insisted that drilling would cause infection. “Immediately after FDA approval, we conducted a study on our first 250 patients, and it worked like a charm,” Miller says. “It had a 97 percent success rate, saved lives, and had no infections and no complications.” But even after studies had proven the value of the drill, uptake of the technology was still slow, say experts. “We in medicine change very slowly,” Bolleter says. “We don’t adopt new ideas easily. Most people didn’t realize the importance of this technology at first.” Growth Potential

In 2005, however, the medical world began to see the wisdom in Miller’s device, which by that time had been dubbed EZ-IO Intraosseous Infusion System. “There were some early adopters — people who ‘got it’ immediately,” Bolleter says. “Since that time, some of the most prominent physicians and nurses in the country have rallied behind it and written articles about it. But it went slow at first.” Indeed, EZ-IO appears to be taking off now. In 2008, it won The Wall Street Journal’s Gold Technology Innovation

EZ-IO works because veins and arteries pass blood in and out of bones.

Volkmann Canal

Award and during the first half of 2009, revenues jumped 30 percent over the previous year. Sales of the device also recently topped the 500,000 mark. Still, the little company’s engineering staff continues to improve the device. To eliminate the possibility of batteries degrading over time, engineers recently switched from eight AA-sized alkaline batteries to AA-sized lithium units, which provide about 20 times as much life. Vidacare engineers say they got the idea for the battery pack and other improvements from users in the field. “You’ve got to be willing to do continuous improvement,” Titkemeyer says. “We’ve done an extraordinary job of putting the product out there and then saying, ‘That’s not good enough.’” Recently, the engineering staff has begun taking the technology to new medical fronts. This month, Vidacare rolled out a drill-based product known as the OnControl Biopsy System, which enables doctors to shorten painful bone marrow biopsy procedures from seven minutes to about five seconds. “Patients who have leukemia have to get biopsies four or five times a year, and they hate it,” Miller says. “With this, we cut the length of the procedure down to 15 seconds at worst. The patients like it better and so do the oncologists.” The company says it will continue to innovate. Miller is considering branching into areas involving orthopedic surgery, dental care and even veterinary medicine. “We’re still very early in the game,” says Philip Faris, the firm’s CEO. ”We have a high amount of growth potential left.” Vidacare’s staff members say if the business grows fast, they’re ready. In his office, Titkemeyer keeps a photo of a paramedic, a smiling mother and her child, who was saved by EZ-IO after nearly drowning in a pool. “When I’m working, I look at that picture,” Titkemeyer says. “Then I know why I’m putting in all the long hours.” • Watch an animated video of EZ-IO at work: http://designnews.hotims.com/23129-531. • Go to http://designnews.hotims.com/23129-532 to watch a video of an IV being fused into a tibia. • Watch Miller perform a knee aspiration with EZ-IO: http://designnews.hotims.com/23129-533. • Watch a demonstration of the power and ease with which the EZ-IO can penetrate bones as fragile as an egg: http://designnews.hotims.com/23129-534. • This fluoroscopy video demonstrates in real time fluids reaching the heart using the EZ-IO inserted into the humerus bone: http://designnews.hotims.com/23129-535. • Watch an actual demonstration of the EZ-IO being inserted into the humerus: http://designnews.hotims.com/23129-536. D E S I G N N E W S D E C E M B E R 2 0 0 9 [ w w w. d e s i g n n e w s . c o m ] 4 7


BY JOHN LOUGHMILLER, CONTRIBUTING EDITOR

Emerging Technologies: Distributed Electro-Hydraulic Systems A zonal approach to hydraulic systems has great potential benefit for airliners, if design engineers can overcome the technology and bureaucratic barriers

E

ntrenched technologies are often thought to be flywheels of infinite mass: You can’t change their speed or direction. Throw in a federal bureaucracy with absolute power over approval of a replacement technology and you have something that veteran engineers are very familiar with: A project with technical obstacles compounded by bureaucratic delays.

Distributed Versus Centralized Systems

Air loads on modern airliner flight surfaces and landing gear are high and mass is great so force multipliers –– high pressure hydraulics –– are the control systems of choice and have been for decades. However, because of the weight and complexity of the engine-driven, centralized system, fluid power companies are working on an alternative: A squadron of electrically powered Hydraulic Power Packs (HPPS) located near the actuators they drive, but far away from the rotating components of the jet engines. Operationally, this means that hydraulic systems become zonal (see bottom figure, page 49), with long runs of vulnerable tubing eliminated along with many of the manifolds and significant quantities of hydraulic fluid. If access panels are intelligently co-located with the HPPS, maintenance time is reduced as well. Catastrophic failure modes are better controlled, system pressure losses are minimized, and a weight savings of around 15 percent is projected. As an example of the current approach, the new Boeing 787 Dreamliner hydraulic system (see top figure, page 49) features a primary pump on each engine plus a third, slipstream driven RAT (Ram Air Turbine) to operate the actuators in an emergency. Separate, dedicated pumps cycle the landing gear. Filters, manifolds and flow directors are part of the system, and 48

D E S I G N N E W S D E C E M B E R 2 0 0 9 [ w w w. d e s i g n n e w s . c o m ]

hydraulic fuses are employed to sense and seal problems in any of the three branches. These standard systems work well, but are complex and hardware-intensive. And because there’s so much high-pressure hydraulic tubing used, leaks are a frequent maintenance issue. So it’s no surprise that companies have been working on an alternative. “Adoption of zonal hydraulics will have a definite effect on the design of airplanes,” says John Halat, chief engineer, Advanced Development at Eaton Aerospace Group. “Most of the major hydraulics suppliers have development activities in this area.” The hydraulic industry’s trade organization, the National Fluid Power Assn., believes the technology has potential once specific uses (such as zonal systems for airliners) have been identified and the technical challenges overcome. As a consequence, it has been working with its members to develop a road map for success in this area. Airliner Technical Challenges

Engineers are no doubt busy working on the technical challenges, which inevitably will involve some wrestling with trade-offs in the choices to be made. Halat says he feels that one of the principle airliner challenges is to increase the capability of the current HPP electric motors by a factor of 10 without increasing the weight by anything near that amount. “Today’s 5 to 10-kW HPP motors are sufficient to operate many of the flight control actuators, but it takes from 50 to 100 kW to cycle the landing gear,” he says. There may be another way to skin this cat, though. Dr. John Hansman, a professor of aeronautics at MIT where he teaches aircraft system design, suggests another approach would be to charge up accumulators and use the stored energy to over-


Today: Typical Centralized Hydraulics System RAM Air Turbine

Hydraulic Pump

Hydraulic Pump

Left Engine

Hydraulic Pump

Right Engine

adds weight, it may be unavoidable in some cases. Halat and Hansman share an enthusiasm for the technology. They both think the use of HPPS would cut down on assembly time and total parts count, which the airframe manufacturers would love. But how much of a weight reduction will occur is up for debate. Halat says he believes a 15 percent reduction in weight will result from eliminating many of the manifolds and the need to run redundant hydraulic tubing throughout the wing and tail structure or fore and aft in the fuselage. Hansman, on the other hand, thinks some weight reduction may result but he’s not sure how high the percentage might be. “It depends on the execution of the design. It certainly saves weight to run electrical cables instead of hydraulic tubing,” says Hansman. “But if you have to use up portions of the weight reduction budget compensating for other problems — like the HPPS noise issues or the landing gear motor size — the 15 percent reduction probably won’t be realized.”

Hydraulic Systems Switching Aux Power Unit

Hydraulic Pump

Manifolds

Actuator Controllers

Hydraulic Actuators

Primary pumps on each engine, plus the APU (auxiliary power unit), can supply high-pressure hydraulic fluid to the actuators. A RAT (Ram Air Turbine) can be lowered into the slipstream to supply emergency hydraulic power via a fourth system. Separate pumps power the landing gear and pressure from the RAT can also be routed to the landing gear in an emergency.

come the power shortage. In Hansman’s view, this makes the instantaneous power requirements much lower, with the same results. Another challenge for engineers is coming up with a strategy to manage the reaction of hydraulic fluids to high altitudes. Jet airliner systems require fluid reservoirs to be pressurized, because at high altitudes hydraulic fluids outgas and foam. In a centralized system that’s easy to manage, as there is only a few large reservoirs. But in a distributed system there is a large number of small reservoirs that will need pressurization. “The physics is the same for the small HPPS, but if you pre-charge the reservoirs and you have good seals, the hydraulic fluid isn’t likely to foam,” says Hansman. The solution would require fitting all the HPPS with pressurized reservoirs and then monitoring the state of the air charge so that a pressure loss would be shown on the cockpit system status displays as an early indication of impending loss of a HPPS. No breakthrough technologies are required, but a wellexecuted design approach would be needed. Another challenge is coping with the noise generated by multiple HPPS Flight Control Devices constantly cycling on and off. Halat and his group believe the best design approach is to locate the HPPS as far from the passengers as possible and acoustically shield those that have to be placed near the fuselage. Hansman agrees. “Placement of the HPPS as far away from the seating areas as feasible is critical, so the short rise time noise of the HPPS turning on and off doesn’t frighten the passengers,” he says. He also agrees that although acoustic shielding

The FAA: Biggest Obstacle of All?

Given enough time and money, engineers are likely to solve all the technical challenges. But since a distributed hydraulic system has never been done before — at least not in airliners — convincing the FAA to certify it may prove to be the biggest challenge of all. In order to be successful, fluid power companies and airliner manufacturers will have to work hand in hand. Tomorrow: Conceptual Distributed Electro-Hydraulic System Left Flap

A

Actuators Flow Diverter

Control Logic Input To Flap and Aileron Flow Diverters Left Aileron

B Normal and Backup Control Logic

Actuators Flow Diverter

AC Power

Control Logic Input

A

B

Hydraulic Pump

Hydraulic Pump

AC Motor

To HPP Control Electronics

AC Power

C

AC Motor

Hydraulic Pump AC Power

Pressure Sensors A,B,C

Position Sensors A,B

Flight Control Commands

AC Motor

Control Electronics

Control Electronics

Control Electronics

Primary Flap HPP

Primary Aileron HPP

Back Up Aileron/Flap HPP

Pressure Sensors Position Sensors

Control Logic Input

In this simplified drawing, flight control inputs from the cockpit are fed to a control logic unit which commands the proper HPP to pressurize its actuators. In the event of primary HPP failure, the pressure sensors detect a problem and the control logic unit automatically flips the flow diverter which substitutes the backup HPP for the failed unit. D E S I G N N E W S D E C E M B E R 2 0 0 9 [ w w w. d e s i g n n e w s . c o m ] 4 9

»


Emerging Technologies: Distributed Electro-Hydraulic Systems

According to FAA airworthiness inspectors contacted by Design News, the provisions of the rules governing aircraft certification, (Federal Air Regulations, Part 21 and its subparts), indicate that an airframe manufacturer seeking an aircraft type certificate is ultimately responsible for policing the suitability of parts used in a new airliner. The inspectors also point out that the parts manufacturers must adhere to the relevant provisions of the same FARs. Both hurdles have to be cleared. FAA certification personnel demand that any new way of doing things is, at minimum, as safe as the technology it’s replacing. It matters not whether the new idea might save lives. Until proven that it will not place more lives in danger than the old technology, it’s a non-starter. Computer simulations will help, but the fluid power companies and aircraft manufacturers must both demonstrate that they have

Dedicated HPPs for Industry: Same Coin, Reverse Side The fluid power industry trade group, the National Fluid Power Assn. (NFPA), has concluded as part of its technology road map that different types of zonal hydraulic solutions need to be identified and made available so that hydraulics is competitive against electromechanical solutions in the next decade. Zonal Hydraulic Power Pack Systems (HPPS) solutions for airliners are unique compared to many — if not most — industrial requirements. While airliner operational needs provide an excellent reason to compartmentalize hydraulic systems, industrial advantages tend to be found in the ability to support specialized requirements. Moog Industrial Group refers to the zonal HPPS approach as EHA which stands for “Electro Hydrostatic Actuation.” The name relates to the device being self-contained with the control electronics, motor, pump, accumulator and actuator considered one assembly. To Moog, “zonal” is a use for the technology whereas “EHA” is the technology. Dave Geiger, hydraulic systems engineering manager, says he believes that in industry application the secret is matching needs to capabilities. He says there are five core needs related to industrial application of HPPS systems: • Actuators that require high-energy efficiency and environmentally friendly solutions. • High cycles applications that see a significant amount of impact shock. • Solutions requiring actuation with greater then 25 tons output force and 4 inch/sec velocities. • Replacement hydraulics in applications that require a high level of environmental awareness (e.g., energy saving, clean, less components). • Replacement hydraulic actuation for systems that have difficulty working in harsh environments such as high ambient pressure, temperature extremes and high levels of shock and vibration. Moog’s engineers believe that finding customers with needs in at least one of these five areas is the key to achieving accep-

50

D E S I G N N E W S D E C E M B E R 2 0 0 9 [ w w w. d e s i g n n e w s . c o m ]

rigid testing programs in place: programs that stress discovering potential failure modes, achieving repeatability of results, demonstrating adequate safety margins and use of redundancy where required. And the aircraft manufacturer has to demonstrate that the new system works in concert with the other aircraft systems and that it’s at least as safe as the current centralized system. But there’s a good prospect of gold at the end of the rainbow. The requirements for certification are spelled out in the FAA’s rules. If the fluid power companies and the aircraft manufacturers keep a copy of that guidance handy and keep the FAA advised of their actions every step of the way, there’s no reason for this technology to remain characterized as “emerging.” In a few years we could instead be calling it “Leading Edge.” John Loughmiller is an engineer, commercial pilot, flight instructor and a lead safety team representative for the FAA. tance of the new approach. To test one such need, Moog recently embarked on a project to validate some of the assumptions driving the technology. Geiger explains: “The research project was based on an actuator that would tilt a high-speed train car as it advanced around a bend. The actuator had a 15-ton capability with maximum velocity of 3 inch/sec and was benchmarked against an electromechanical actuator. We later determined that this was not a good benchmark because the output level required was within the capabilities of electromechanical solutions. “We need to be in output ranges of greater then 25 tons and 4 inch/sec velocity to be more attractive than electromechanical actuator solutions. The major advantage is that the mechanics are more robust, so the system can take much higher levels of impact shock. Also it’s very easy to build in fail-safe functionality.” Even though the test was not perfect, engineers obtained extremely valuable data and Moog believes the time and money were well spent. According to Geiger, although the technology is ready for deployment in situations like those listed above, there are some issues that need addressing. “Because EHA technology has not been adopted by the industrial segment, there are barriers, such as being able to reach cost targets without having any critical volume to drive down the costs,” he says. “Also technicians are not trained in EHA technology. Today’s technicians are trained in electromechanical or classic hydraulic solutions,” he adds. Moog has developed documentation that explains the HPPS technology developed by its industrial group and its sister company, the aircraft group: • Industrial Applications: http://designnews.hotims.com/23129-537 • Aircraft Applications: http://designnews.hotims.com/23129-538 • National Fluid Power Assn. — engineers may want to contact the NFPA and request the report that shows the results of the technology roadmap: http://www.nfpa.com/


TREND WATCH • DESIGN

MOTION CONTROL

APPLICATIONS

Monitoring Machine Performance Plant floor to enterprise connectivity is easy with KEPServerEX

Source: Kepware

O

racle®, the world-leading database company, developed plant floor analytics — a new solution specifically oriented to the manufacturing marketplace. The Manufacturing Operations Center (MOC) is a stand-alone solution that delivers real-time operational intelligence with its own S95-based data model (separate from ERP). Architected to be ERP agnostic, it is designed as a unified plant data repository with integration to ERP, MES, data historians, SCADA and other types of shop floor systems. To gather real-time streaming data from plant equipment and control systems, Oracle enlisted a key partner, Kepware Technologies, the world leader in communication software for automation. Kepware offers a unique experience in both OPC and embedded device communications. Since 1995, Kepware has focused on the development of communication drivers to automation controllers, I/O and field devices. Operating system support includes Microsoft Windows Desktop, Windows Server and Windows Embedded (Windows CE and Windows Embedded NT/XP). Today, Kepware delivers connectivity to thousands of devices through more than 130 communication protocols.

KEPServerEX delivers MOC to equipment integration.

Performance Testing Objective

The selection of an external partner for connectivity solutions demanded close scrutiny of usability, performance and overall support. Testing communication partners and PLCs in both real-world and exaggerated scenarios occurs at the Oracle Manufacturing Operations Center Lab by a third party, Geometric, which specializes in the domain of engineering solutions, services and technologies. Under high data intensity and volume, KEPServerEX OPC Server exceeded the normal response time to handle high frequency data with extreme accuracy. The performance testing demonstrated flawless functions between the two products, enabling optimum manufacturing operations. Conclusion

Kepware now ships Oracle Manufacturing Operations Center’s Connectivity Suite that can be configured to collect specific device tags in real time and transfer them over to Oracle Manufacturing Operations Center.

D E S I G N N E W S D E C E M B E R 2 0 0 9 [ w w w. d e s i g n n e w s . c o m ] 5 1


2009

BEST OF THE ENGINEERING MARKETPLACE

B E S T

52 53 54 55

P R O D U C T

A W A R D S

Winner

E l e c t ro n i c s Fluid Power Materials/Fastening M o t i o n C o n t ro l

®

Compiled by Elizabeth M. Taurasi

»

ELECTRONICS

SHOCK & VIBRATION

SOLUTIONS Silent Feet ®

SMT version features gold-plated phosphor bronze contacts. The THM version incorporates tin-plated phosphor bronze contacts and the heat-resistant nylon housings. The THM types mount directly on PCBs and are securely positioned during wave soldering and placement. Both holders accept 1/3N 3-V cell lithium batteries from major manufacturers and are part of the company’s continuing growth selection of battery hardware specialties. Keystone Electronics Corp.

http://designnews.hotims.com/23129-542

STDK’S DIN RAIL POWER SUPPLIES Operate with three-phase ac inputs TDK-Lambda’s new series of ac-dc DIN Rail-mount power supplies has outputs rated from 120 to 480W that operate off a three-phase ac line input from 340 to 575V ac. They are ideal for factory automation, industrial control systems and test and measurement equipment. Each series is available with the most popular output voltages: 12 and 24V dc outputs are available in the DPP120 series (rated at 120W), and 24 and 48V dc outputs are available in the DPP240 series (rated at 240W) and the DPP480 series (rated at 480W). An important feature of these new units is their bi-phase operation; under a dropped phase condition they will continue to operate with the output power derated to 80 percent.

Using advanced Sorbothane® polymer technology, Silent Feet,® vibration isolating pads, absorb harmful and noisy vibrations caused by appliances such as washing machines and dryers. TheVibrationSolution.com. Sorbothane® is the ultimate isolation material for absorbing shock and vibration. No other material can dissipate energy as effectively. Engineers worldwide choose Sorbothane® for applications requiring shock absorption, vibration isolation and damping.

MADE IN

U.S.A.

TDK-Lambda Americas Inc.

http://designnews.hotims.com/23129-541

KEYSTONE ELECTRONICS’ 1/3N LITHIUM BATTERY HOLDERS

s RAPID PROTOTYPING s LOW-COST TOOLING s FAST TURN AROUND ®

SHOCK & VIBRATION

SOLUTIONS

800.838.3906 www.sorbothane.com

With durable, heat-resistant housings With the introduction of a new selection of rugged, 1/3N Lithium Battery Holders for surface or through-hole mounting, Keystone Electronics Corp. continues to expand the availability of premium battery holders. These new battery holders are supplied with durable, heat-resistant, UL 94V-0-rated nylon housings ideal for all soldering and reflow operations. The

SPOSITRONIC™’S HIGH-DENSITY COMBO D CONNECTORS For low to midrange power applications Positronic™’s Combo D connectors offer signal, power, coax and high-voltage contacts mixed within a single connector package, and are available in all six standard D-sub shell sizes. They also offer a multitude of contact variants. Positronic’s CBDD series offers size 16 power contacts for low to midrange power applications. These new configurations allow increased density not previously achieved in combination connectors. CBDD size 22 contacts have a contact resistance of 0.010 for open-entry design and 0.005 for closed-entry design. Closed-entry contacts can also be used for low power requirements and are rated at 5A nominal. Standard size 16 power contacts have a contact resistance of 0.0016 and are rated at 28A per UL 1977. High conductivity options offering higher current ratings and lower contact resistance are available. Positronic™ Industries

http://designnews.hotims.com/23129-543


ELECTRONICS, Continued

from a universal input of 85 to 264V ac, providing tightly regulated single outputs of 3.3, 5, 9, 12, 15 or 24V dc. Standard features include universal 85 to 264V ac inputs, filtering to EN55022, input/output isolation of 3,000V ac and very low leakage current. All models are protected for over-temperature and short-circuit faults. The MPM-03S is RoHS-compliant and has a Class II input (IEC61140), which means it can be used without an earth ground connection. Each model is specified for operation over the wide operating temperature range of -25 to 71C (ambient). MicroPower Direct LLC

http://designnews.hotims.com/23129-545

»

FLUID POWER

SOSRAM’S MINI LASER BARS Application-specific product families The new generation of mini laser bars from OSRAM Opto Semiconductors offers exceptional brilliance in the wavelength range from 910 to 1,020 nm. They are cost-effective, durable and can be easily adapted to meet the requirements of different applications thanks to their small size. In contrast to conventional fiber-coupled diode laser systems, the new bar structures allow more costeffective beam-forming concepts to be used for fiber coupling. The associated reduction in system costs is a major factor in making diode laser systems more attractive for direct material processing — particularly in comparison with alternative laser solutions. Mini laser bars are available in various application-specific product families, with fill factors of 10 to 20 percent and typical efficiencies of up to 65 percent. In addition to pumping fiber lasers, the laser bars are also used for direct micro-material processing, such as marking and micro-welding.

SQOSINA’S ZERO DEAD SPACE SYRINGE Minimizes waste, maximizes product Qosina now has a 1 ml male luer slip, two-piece syringe featuring an extended plunger with zero dead space. This eliminates pharmaceutical waste and the positive safety stop protects against accidental spills. The polyethylene plunger and polypropylene barrel offer more chemical resistance than conventional rubbertipped syringes and contains no DEHP, latex, silicone oil or Styrene. The syringe has scale markings to the hundredths for enhanced accuracy. Custom sourcing service is also available.

OSRAM Opto Semiconductors

Qosina Corp.

http://designnews.hotims.com/23129-544

http://designnews.hotims.com/23129-546

MICROPOWER DIRECT’S MPM-03S SERIES OF SINGLE OUTPUT, 3-W SWITCHING POWER SUPPLIES

CLIPPARD INSTRUMENTS’ NEW PUSH/PULL VALVES

In an ultra-miniature DIP package MicroPower Direct’s MPM-03S series is a family of single output, 3-W switching power supplies. These low-cost modules include a universal ac input, full safety approvals, robust filtering and miniature DIP packaging. Six standard models operate

With operating temperature of 32 to 140F, 0-115 psig operating pressure Clippard Instrument Lab. Inc.’s new line of manually operated Push/Pull Valves are available in both three- and four-way configurations. Available in detent or momentary versions, these new valves provide the flexibility for unlimited applica-

tions, and have an operating temperature of 32 to 140F and an operating pressure of 0-115 psig. Clippard Instrument Lab. Inc.

http://designnews.hotims.com/23129-547

KNF’S NF600 DIAPHRAGM PUMP Compact solution for dosing liquids KNF’s new NF600 self-priming diaphragm pump for dosing or transferring liquids incorporates advanced four-diaphragm technology to promote smooth and continuous flow, low pulsation and vibration, quiet-running performance and maximized efficiency. This compact solution (as small as 135 x 111 x 105 mm) can deliver a nominal flow rate of 6/min, suction height of 8.8 inch Hg and pressure up to 15 psig. They are well-equipped for medical diagnostic analyzers, dialysis liquid circulation, water treatment and analysis, ink-jet printers and semiconductor operations, among other applications. NF600 pumps are available in three motor types (ac, brush-commutated dc or brushless dc) and can provide stable pumping action over a potential service life exceeding 50,000 hours. The pumps require minimal maintenance and are designed without tubing to eliminate possible pump failure due to tubing fatigue or rupture. KNF Neuberger Inc.

http://designnews.hotims.com/23129-548

SINSERTA® BALL VALVES For use in challenging environments Inserta® Ball Valves are now available with an optional Electroless Nickel Plating of all exterior surfaces for use in challenging environments. Electroless Nickel Plating offers significant corrosion resistance at a fraction of the price of stainless steel. In many instances these valves are available to ship within 48 hours after receipt of order. Inserta®

http://designnews.hotims.com/23129-549

D E S I G N N E W S D E C E M B E R 2 0 0 9 [ w w w. d e s i g n n e w s . c o m ] 5 3


»

M AT E R I A L S / FA S T E N I N G

TEVONIK’S TROGAMID® MYCX Available as a granulate and as a transparent, colorless film Evonik Industries AG has expanded its TROGAMID® CX range to include the new TROGAMID myCX, which stands for a new premium brand of microcrystalline high-performance polyamide and was improved specifically for the manufacture of sports glass and sunglass lenses. Evonik also offers plastic films made of TROGAMID myCX, which are clear as glass and suitable for laminating and decorating optical parts. It is permanently transparent, allowing a light transmission of 92 percent. Because of the low density and the high break- and scratch-resistance of the high-performance polyamide, sunglass lenses made of this material are not only exceptionally light, but safe. The films come in standard thicknesses of 125 and 400 micrometers. Other thicknesses can be provided upon request. Evonik Degussa AG

http://designnews.hotims.com/23129-550

MASTER BOND’S THERMAL ADHESIVE FILM

Kep-O-seal䉸 Adjustable Relief Valves Available as in-line or cartridge insert types, these valves feature the industry proven Flexible Seal Seat娃 design which provides dependable control of liquid or gas. Direct operating and spring loaded, they are designed for applications requiring fast acting relief performance and tamper-proof pressure adjustment. Fully adjustable 50 to 2000 psi. For details visit: www.kepner.com

With quick-cure ability at moderate temperatures Master Bond’s thermal adhesive film FL901AO is formulated to function as the preferential heat-transfer path between heatgenerating components and heat sinks or other cooling devices. The 100-percent solid, B-stage adhesive preform provides a high bond strength, no-mess solution to electronic assembly and other industrial bonding and sealing operations. It can cure quickly at moderate temperatures, e.g. 1 hour at 250F (125C) or 30-40 min at 300F (150C). It also features high resistance to thermal shock, vibration and impact. Master Bond Inc. http://designnews.hotims.com/23129-551

TFUJIPOLY’S SARCON® GR-SD THERMAL GAP FILLER PAD Conforms to protrusions, depressions Fujipoly announces the availability of Sarcon® GR-Sd, one of the industry’s lowest compression force thermal gap filler options. It is engineered to efficiently transfer heat from its source to a


TBECKHOFF’S VERSAVIEW™ DROP-IN REPLACEMENT PANELS

M AT E R I A L S , C o n t i n u e d

nearby heat sink in applications that require extremely low force on the component, as well as a high adhesion characteristic. Sarcon GR-Sd easily conforms to protrusions and depressions on components to make complete, reliable physical contact. The gap filler pad is available in 2.5- and 5.0-mm thick sheets up to a maximum 200 x 300 mm. The physical characteristics of this product also allow it to act as a low-pressure vibration absorber and electrical isolation material for bare leaded applications. Fujipoly America Corp.

http://designnews.hotims.com/23129-552

»

MOTION CONTROL

Modified enclosures permit quick replacement To provide a low cost and reliable alternative for VersaView™ panels, Beckhoff Automation now offers control panels for quick replacement of 12- and 15-inch VersaView displays. Beckhoff has designed variants of CP6xxx series control panels and panel PCs with modified enclosures to permit simple drop-in after removal of Allen-Bradley™ VersaView panels from machines and electrical cabinets. The front side is rated with IP65 protection and the rear side with IP20. Beckhoff Automation

http://designnews.hotims.com/23129-555

SPECIALTY MOTIONS’ X-TREME™ PRECISION STAGE

W AUTOMATIONDIRECT®’S LED SENSOR CABLES Available in six lengths AutomationDirect® has extended its sensor cable offering to include quickdisconnect and patch cables with LED indicators. The new patch cables have a right-angle M12 female plug with an LED indicator on one end and an axial male connector on the other. Available in six lengths ranging from 0.3 to 10m, the cables feature a polyurethane jacket for dependable use in oily and direct sunlight applications. Prices for patch cables with LED indicators start at $10.75. Also added are quick-disconnect cables with an LED indicator to confirm signal presence. Fitted with industrystandard M12 right-angle female plugs, these cables can be used with patch cables to extend distance. They are available in 2-, 5- and 10-m lengths. AutomationDirect®

http://designnews.hotims.com/23129-553

WAGO’S BLUETOOTH® RF-TRANSCEIVER MODULE For applications from robot controls to high bay warehouses WAGO Corp.’s 750-644 Bluetooth® RF-Transceiver module provides fast, bi-directional, wireless communication between I/O nodes. Within 10 ms, the 750-644 exchanges data up to 1,000m (line-of-sight) or 100m (within buildings), providing control engineers with a cost-effective wireless solution. This makes the 750-644 ideal for a wide range of applications from robot controls and high bay warehouses to both renewable and traditional energy applications, such as oil fields. One 750-644 master can communicate with up to seven slaves on a Personal Area Network (PAN), also known as a piconet, via Bluetooth 2.0+EDR radio technology. Slave-to-slave data transmission is possible indirectly through the master.

Compact envelope, low-profile design Specialty Motions Inc. has added X-TREME™ Nano-translation Cross Roller Stage to its family of linear motion systems. This compact, high-performance stage is capable of accuracies up to .14 nm at industry-leading speeds up to 6.5m/sec. It is currently one of the smallest of its class, touting a compact envelope and low-profile design with load-bearing capacities up to 1,100 lb based on 2 mil inch travel. Specialty Motions Inc.

http://designnews.hotims.com/23129-556

Phone: (516) 328-3662 Fax: (516) 328-3365

THE NEW V110 CATALOG • Air Springs • Circular Cable Isolators • Constant Natural Frequency Mounts • Seismic Mounts • Thermal Conductive Silicone Products • Wedge Levelers • Foot Mounts

...adds hundreds of new items to our extensive product line available in the V100 catalog

WAGO Corp.

http://designnews.hotims.com/23129-554

www.vibrationmounts.com 55


L I T E R A T U R E

P L U S

Get the latest in design guides, catalogs and other product information from every part of the OEM.

Please enter reader service number at www.designnews.com/info for additional information from manufacturers. TO ADVERTISE CALL 800-387-3469

BOKERâ&#x20AC;&#x2122;S FREE 2010 WASHER CATALOG

SHOCK ABSORBERS

Washer Catalog features over 24,000 nonstandard flat washer sizes available with no tooling charges. ODs of 0.080â&#x20AC;? to 5.140â&#x20AC;?, a range of IDs and thicknesses, as well as 2,000 material options provide endless washer possibilities. Materials include numerous carbon steels, stainless steels, aluminums, brasses, coppers and non-metallics. ISO 9001:2008 Registered.

New ACE Controls catalog on its full line of industrial and safety shock absorbers, as well as feed controllers. Products include: award winning Magnum Group and SC2 Heavyweight Series and new SC High-Cycle Series for decelerating loads, preventing impact damage, dampening noise and increasing cycle speeds. Self-compensating and adjustable models.

Bokerâ&#x20AC;&#x2122;s, Inc.

ACE Controls Inc.

T: 888-927-4377 â&#x20AC;˘ F: 800-321-3462 Email: sales@bokers.com Web: www.bokers.com/dnlw

T: 800-521-3320 â&#x20AC;˘ 248-476-0213 Email: shocks@acecontrols.com Web: www.acecontrols.com

Go to http://designnews.hotims.com/23457-6000

Go to http://designnews.hotims.com/23457-6001

ADVANCED CERAMIC SOLUTIONS

POSITION TRANSDUCERS

Astro Metâ&#x20AC;&#x2122;s unique advanced ceramics provide cost effective solutions to material performance problems in a wide range of demanding applications. â&#x20AC;&#x153;Amalox 68â&#x20AC;? a 99.8% alumina ceramic and â&#x20AC;&#x153;Amzirox 86â&#x20AC;? a yttria stabilized zirconia provide superior wear resistance, corrosion resistance, high temperature stability, low thermal expansion, high stiffness to weight ratio, biocompatability and high dielectric strength.

 PAGE%NGINEERING'UIDEDESCRIBESHOWTO select and use InductosynÂŽ and ElectrosynÂŽ position transducers for demanding applications. Rotary InductosynÂŽ and ElectrosynÂŽ transducers provide absolute and incremental position information accurate to Âą0.5 arc SECONDS OR BETTER 2ESOLUTION TO  BITS Linear transducers are accurate to Âą40Îź inches or better, with sub-Îź inch resolution.

Astro Met, Inc.

Valhalla, NY USA 4  s&   E-mail: sales@ruhle.com Web: www.ruhle.com

Cincinnati, OH 45215 T: 513-   H -772-9080 Web: www.astromet.com

Farrand Controls

Go to http://designnews.hotims.com/23457-6003

Go to http://designnews.hotims.com/23457-6002

LP1

PRECISION ALUMINUM EXTRUSIONS

NEW ELECTRIC HEATER CATALOG

NEW! An informative brochure from MINALEX, the leader in precision shapes to 3½â&#x20AC;? circle size with tolerances to Âą.001â&#x20AC;? and walls down to .008â&#x20AC;?. Brochure illustrates a wide variety of typical applications and describes capabilities including short and prototype runs. MINALEX, the quality leader of the industry, delivers on time, every time.

Hotwatt manufactures electric heaters including cartridge, air process, immersion, strip and finned strip, tubular and finned tubular, band, crankcase, foil, flexible glasrope and ceramic heaters. We have been manufacturing resistance heating elements since 1952 and offer a wide variety of heaters for OEM, industrial, commercial, medical and military applications.

MINALEX

Hotwatt, Inc.

Web: www.minalex.com

4  s&   E-mail: sales@hotwatt.com Web: www.hotwatt.com

Go to http://designnews.hotims.com/23457-6004

Go to http://designnews.hotims.com/23457-6005


ELECTRIC ACTUATORS

PEEK fasteners have a number of key advantages over stainless steel: about 1/5 the weight, di-electric properties, corrosion-proof, low thermal conductivity, and anti-magnetic. Used in mobile phones, consumer electronics, radiation and medical equipment, chemical and fluid processing, aerospace and automotive industries, PEEK offers one of the best price/performance profiles.

RACO Ball & ACME screw Electric Actuators cover a broad range of applications, are environmentally friendly, robust & low maintenance replacements for hydraulic/ pneumatic cylinders. The modular system design allows for Straight/Right-Angle/CDesign variations. Thrust up to 225,000 lbs, speeds up to 30”/sec, and strokes up to 20 feet. For fast linear movements up to 400”/sec RACO produces a belt driven LM-Actuator.

NetMotion, Inc. T: 510-578-2808 • F: 510-743-4130 Email: sales@netmotion.com Web: www.netmotion.com

RACO International, L.P.

T: 1-800-BUY-RACO Web: www.racointernational.com

Go to http://designnews.hotims.com/23457-6006

SPIRAL RETAINING RINGS & WAVE SPRINGS Smalley’s complete product line is now available in one easy to navigate catalog. The new catalog includes over 7,000 standard wave springs, spiral retaining rings and snap rings. Smalley’s new catalog offers simplified part selection, special design and engineering tools and the latest applications of Smalley products.

Smalley Steel Ring Company T: 847-719-5900 E-mail: info@smalley.com Web: www.smalley.com/catalog.asp

Go to http://designnews.hotims.com/23457-6008

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SMART MARKETING ALWAYS includes positive editorial about you or your company

L I T E R AT U R E P L U S

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SEAL MASTER INFLATABLE SEALS, ACTUATORS & GRIPPERS Solve difficult, awkward design problems with Seal Master® Inflatable Seals. Custombuilt, fabric reinforced, and fully molded, these elastomeric seals and other pneumatic specialties offer close tolerance capability and resistance to compression. Use for imaginative production / processing applications too. Design assistance offered.

Seal Master Corporation T: 800-477-8436 • F: 330-673-8242 Email: info@sealmaster.com Web: www.sealmaster.com Go to http://designnews.hotims.com/23457-6009

L I T E R A T U R E P L U S ADVERTISERS INDEX ACE CONTROLS, INC. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . LP1 ASTRO MET, INC. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . LP1 BOKERS, INC. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . LP1 FARRAND CONTROLS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . LP1 HOTWATT, INC. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . LP1 MINALEX CORPORATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . LP1 NETMOTION, INC. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . LP2

The YGS Group 800.290.5460 x100 rbi@theYGSgroup.com The YGS Group is the authorized provider of custom reprints and content licensing from Reed Business Information.

RACO INTERNATIONAL L.P. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . LP2 SEAL MASTER CORPORATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . LP2 SMALLEY STEEL RING CO. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . LP2 PUBLISHER DOES NOT ASSUME ANY LIABILITY FOR ERRORS OR OMISSIONS IN THIS INDEX. LP 57 2


CALAMITIES

Tr u e S t o r i e s

The Case of the Buckled Brace “One size fits all” does not apply here TITANIUM IS A DESIGN ENGINEERS’ DREAM AND A

process metallurgists’ nightmare. The strengths and ductilities of titanium alloys are comparable with those in steels, but the density is over a third less. This weight savings is crucial in aerospace applications where high-strength titanium forgings made jumbo jets possible. Titanium, like aluminum and chromium, reacts with air to form a very thin protective oxide film. The resulting corrosion resistance makes titanium alloys competitive with stainless steel for many applications. Unfortunately, titanium is nearly a universal solvent and dissolves almost everything it contacts. This reactivity makes it very difficult to process. Even though titanium ores are fairly abundant, the refined metal is expensive. Titanium costs about as much as premium steak; stainless steel costs about as much as peanut butter. This case involves the failure of a titanium alloy leg brace. The alternative materials would have been stainless steel or aluminum alloys. Apparently, the lighter weight of titanium made it preferable to stainless steel. Titanium is much stronger than aluminum, so it could be used to produce a less bulky brace. The brace broke at the knee joint, causing the wearer to fall and suffer serious injury. I was retained by one of the defendants in the case. We were limited to strictly nondestructive testing, and not even a minimally invasive 58

D E S I G N N E W S D E C E M B E R 2 0 0 9 [ w w w. d e s i g n n e w s . c o m ]

KENNETH RUSSELL PROFESSOR EMERITUS, MIT CAMBRIDGE, MA

hardness test was allowed. I suspected fatigue failure, but the parts of the brace were too large to fit in the scanning electron microscope (SEM). (See “The Case of the Jelly Roll Blues,” DN 04.23.06, http://designnews.hotims. com/23129-539.) We had to use replication of the surface to study the fracture. A plastic dental replicating compound was spread on the fracture surface and allowed to harden. The replica was then shadowed with a very thin layer of metal to make it electrically conducting, and studied in the SEM. Study of the replica revealed the fine striations characteristic of fatigue failure. Fatigue failure occurs under cyclic load. A crack starts at an irregularity known as a stress riser and proceeds little by little with each stress cycle. Finally the crack weakens the piece enough that sudden catastrophic failure occurs. In this case, walking provided the cyclic stress and the sudden final failure caused the injury. This case was peculiar in that both sides of the brace had undergone the same amount of fatigue damage. Most fatigue failures are started by nicks or dings that are unlikely to occur on both sides of the brace. But the brace clearly failed, and my job was to figure out why. Could the brace have been made of faulty titanium? The brace was made of rolled strap, and rolled material is rarely defective. The material in the brace was a very small part of a large batch of strap. If one piece was defective, the whole batch probably was. It appeared that the brace may have been under-designed. I asked my client if the plaintiff was large. The answer came back yes, she weighed some 300 lb. She was one of the last of the pre-Salk vaccine polio victims. The case settled shortly after my study and I never learned any more about the matter. My suspicion, though, was that the brace was designed on a “One Size Fits All” basis and was suitable for some “average” 150-lb user. Such a brace would not be suitable for a user twice this weight. On the other hand, a 90-lb user would be carrying around a heavier brace than she needed. Calamities is picked up regularly in our Made by Monkeys blog. Go to www.designnews.com/madebymonkeys to comment on this article and read more cases.

Ken Russell (kenruss@mit.edu) is professor emeritus of Metallurgy and Nuclear Engineering at MIT. He specializes in physical metallurgy, forensic metallurgy and failure analysis. Cases presented here are drawn from his actual forensic files.


PRODUCTMART

ADVERTISERS IN THIS ISSUE Page

Page

55

Advanced Antivibration Components

35

Mouser Electronics

59

Aero Tec Labs. Inc.

27

National Instruments

C-3

Allied Electronics

36

Northwire Inc.

C-4

Autodesk

30

Numatics Inc.

2

Automationdirect.com

1

OMEGA ENGINEERING Inc.

17

Avnet Electronics Marketing

32-33

Opto 22

59

Bird Precision

10

Paneloc Corp

43

Bishop-Wisecarver Corp.

21

Phillips Plastics Corp.

34

Boker's Inc.

19

R&D Bladder Prototypes Pneumatic Bellows

Proto Labs Inc. Accumulator

44

BuyerZone

54

Press Bladder

Specialists In Bladder Tanks And Inflatables

Clippard Instrument Lab.

6

Condensate Collector

Quality Transmission Components Bio-Fuel Bladder

29

Pipe Plug

Robert Bosch LLC

C-2

Digi-Key Corp.

4

Siemens PLM Software

23

Dow Corning

25

SKF Group

34

Enertrols Inc.

39

Smalley Steel Ring Co.

3

EXAIR Corp.

11

SolidWorks

54

Kepner Products Co.

52

Sorbothane Inc.

37

MicroStrain Inc.

38

Stock Drive Products/Sterling Instrument

8

Moog Inc.

15

TURCK Inc.

Publisher does not assume any liability for errors or omissions in this index.

Compensator Diaphragm

Aero Tec Laboratories Inc. Ramsey, New Jersey 07446-1251 USA Toll Free 800–526–5330 Fax 201–825–1962 e-Mail: atl@atlinc.com

www.atlinc.com

To ADVERTISE in the PRODUCT MART section of

Please contact 800-387-3469 59


GADGET FREAK ONLINE

THE GADGET FREAK® FILES CASE #155

Check Out Gadget Freak Case #152: Tesla Turbine Puts Points on Pesky Pencils Design improvement sharpens pencils at 2,200 rpm: http://designnews.hotims.com/23129-540

Get Wrapped up in Christmas Lights

ADVERTISEMENT “DECK THE HOUSE” Amt

he holiday season brings two questions: “Isn’t it time to put up the Christmas lights?” and “When do we take down the Christmas lights?” Edward Nauman designed retractable icicle lights that go up or down with a flick of a switch. He used rotating lengths of metal conduit to wrap up lights and keep them out of sight behind a facia board. Ed’s invention brought peace to his holiday season. The design involves a bracket, a motor, microswitches, conduit and a few other Check Out the Retractable odds and ends, plus some metalIcicle Lights in Action at www.designnews.com/GadgetFreak working experience.

T

ARE YOU A GADGET FREAK?

Design News and Allied Electronics would like to send you a check for $500 to spend on Allied’s website at www.alliedelec.com/gadgetfreak or anywhere you please. And don’t forget to supply us with a video file of your gadget in action. E-mail Design News your proposed project (must incorporate electronic components and involve sensing, motion, timing and/or networking elements) to jontitus@comcast.net, along with a description of how it works, a parts list, schematic, photos and video. If your project is featured, you’ll receive a $500 check from Design News and will be featured in an upcoming issue of the magazine or at designnews.com with your invention.

60

D E S I G N N E W S D E C E M B E R 2 0 0 9 [ w w w. d e s i g n n e w s . c o m ]

Part Description

Allied Part #

1

NKK DPDT Toggle Switch (on-none-on)

870-0410

2

Microswitch, Honeywell (SPDT)

642-2171

1

Alectron dc Power Connector

283-2551

1

Stancor Plug-in Power Supply, 12V dc at 1A

928-9746

1

Tyco 7-pin Male Connector (211400-1)

512-8603

1

Tyco 7-pin Female Connector (211398-2)

512-0606

Additional Parts Required For a complete list of parts, schematics and build instructions go to www.designnews.com/GadgetFreak

Get Gadget Freak delivered to your desktop: • Newsletter: http://reg.designnews. com/newsletter/subscribe • RSS: http://www.designnews.com/rss/ For parts information, call (800) 433-5700 or go to www.alliedelec.com/gadgetfreak SPONSORED BY »

Photo: Cat Gwynn


10% off all Hammond product solutions @ alliedelec.com.*

For All Your Hammond Enclosure Solutions

THINK ALLIED

SM

1.800.433.5700 © Allied Electronics, Inc 2009. ‘Allied Electronics’ and the Allied Electronics logo are trademarks of Allied Electronics, Inc.

An Electrocomponents Company. * Online only through December 31, 2009.


AUTODESK INVENTOR TAKES YOU BEYOND 3D TO DIGITAL PROTOTYPING

AutodeskÂŽ InventorÂŽ software creates a single digital model that enables you to design, visualize, and simulate your products. Inventor helps you to reduce product costs and get innovative designs to market faster.

Find out more about Autodesk Inventor and how it can take you beyond 3D to Digital Prototyping.

www.autodesk.com/beyond3d

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Design News December 2009  

Design News December 2009

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