BFP: Nature inspired terrestrial robot

Bachelor Final Project

Designing a new DBL project: Nature inspired terrestrial robot

BFP BY SJOERD NARINX WRITTEN BY JANKATIRI BOON

Introduction

For this Bachelor Final Project interview, I spoke with Sjoerd Narinx, who is a 5th year student. He has recently completed his BFP at Microsystems, under supervision of Ye Wang, where he got the opportunity to review and come up with a new challenge for the DBL Peristaltic pump. This BFP was awarded with a 7.5. Sjoerd already had an interest in micro actuators, so doing a BFP revolving around those would be ideal. Another factor for him was the current limited access of most workplaces and laboratories at the University. He did prefer to physically work on something and not have it be very theoretical. In the end, a list of interesting projects was presented and this is the one he chose. The goal of this BFP, was to come up with a new case for the DBL which currently revolves around the peristaltic pump and create a working prototype. The case should change, but the general manufacturing process and materials should remain the same however. The goal behind it though, which is to introduce freshmen to the Microsystems research group and create a general feel for engineering, should not change. This DBL is currently given to freshmen in the third quartile, and it has been part of the curriculum for the past 4 years. It was a replacement for the then Propellor DBL.

Figure 1: The first design

The first steps

At Microsystems, they work a lot with cilia. Which are small slender appendages, found naturally but also made synthetically. These cilia are also used a lot within pumps, so an obvious first step was to investigate how these can be integrated in a new case. Being limited to around the same materials that are used with the regular peristaltic pump DBL, Sjoerd started by collecting said materials and brainstorming about how he could transform these raw materials into something fun and functional, keeping the main goal still in mind. It started really simple, but from one idea came another and eventually this also reflected in how the idea came to realization. It would be fun to create a robot, so we need at least a couple legs, so those should be able to move, etc.

Iterative design

Pretty quickly, Sjoerd started to work in Siemens NX to create a digital drawing of what the robot should look like. He also needed to make a drawing so the components themselves could be lasercut. As advised by his supervisor, Sjoerd created many iterations of the robot. This is useful for data comparison, which would better fundament your conclusion. Every time you create a new version, you find new challenges which you need to overcome, which also keeps you busy. At first, for example, it was becoming obvious that the robot could not walk really straight, because he drilled certain holes by hand. For the following designs the holes were also lasercut, which drastically improved the performance, even though it was a simple problem with a simple solution.

Figure 2: The upgraded appendage

Creative freedom

The background knowledge that you need for a project like this is already really complete within the research section. Since the new case for the DBL had to be created, it was not clear if the project would end up working in the end, but to make sure that the robot would be able to walk the way it was intended, Sjoerd had to keep looking for improvements in the design of the robot to make sure that every iteration would add something to the end result. What Sjoerd really liked was the freedom he got during this BFP. If he needed a simple tool or a screw, he just got it. He was really let loose and could just do his own thing, which he really felt impacted the process of this BFP very positively.

Figure 3: Comparison between the first and final design

The final design

At first the robot had four legs, since in the DBL you also got four servos. Sadly, this resulted in the robot simply tipping over during movement, which needed to be resolved. The final robot ended up with six legs. This improved the maneuverability, but it was mostly important for the stability. The only drawback was that you needed an extra power supply, but that had only very little impact on the maneuverability and stability.

Conclusion

At first Sjoerd thought that a BFP would be really theoretical, but the opposite turned out to be true. At some point it even became kind of a hobby for him. During the Christmas break he returned home and started working on the project with a very enthusiastic dad that wanted to help him where he could. In the end, Sjoerd is not sure if his actual design will make it to the next version of this DBL, but the final design will definitely be based on his prototype. A slight problem is that you don’t want to spoon feed the freshmen with final designs, so something that is for certain is that it will not be presented in the first case supporting lecture. Sjoerd does think that this current case is more fun than the previous, while still keeping the initial fun elements of the previous case, where you basically get presented with a bag of components and the option to lasercut and they then wish you good luck.