2000s
AFOSR: Turning Scientific Discovery into Air Force Opportunity
Super Oil-Repellent Surfaces Research Against Chemical/ Biological Agents, Leaks, and Coffee Stains (2006-present) AFOSR has funded investigations into super oilrepellent surfaces because of their potential utility in cleaning up jet fuel spills and protecting aircraft or rocket parts from fuel absorption. Massachusetts Institute of Technology (MIT) professors of engineering Drs. Gareth H. McKinley and Robert E. Cohen have been exploring man-made and natural surfaces that keep gasoline and oil from soaking in and spreading out over a surface. The challenge is the low value of the surface tension of many oils, which makes them spread over surfaces very easily. Surface tension is a measure of the attraction between molecules of the same composition. The researchers’ goal is to design new solid surfaces with very low interfacial energies that can repel oily liquids. McKinley noted that, “Nature has developed a lot of methods for waterproofing, but not so much oil-proofing.” After studying the water-repellent surfaces of lotus leaves, McKinley and Cohen created a microfiber fabric that can be deposited onto aircraft surfaces via a process known as electrospinning. The microfibers contain fluorinated nanoparticles, FluoroPOSS, which are synthesized by Dr. Joe Mabry and colleagues at Edwards Air Force Base, Calif. Dr. Charles Lee, AFOSR Program Manager for this project, noted that many people are addressing materials that repel water, but few are researching oil repellents, a research topic that is important for many Air Force systems. This collaborative research, involving scientists at MIT and Edwards AFB, will be important for making
future systems more maintenance free. The graduate student who worked on this project at MIT, Dr. Anish Tuteja, continued to conduct research in this area after becoming a faculty member at the University of Michigan. He developed fabrics that have opposite surface properties: one repelling water but not oil, and the other repelling oil but not water. Tuteja was able to demonstrate that this combination of fabrics acts as a filtering membrane by separating an emulsion of oil and water into its pure components simply by the force of gravity. This work may lead to protective coatings for airplane parts, which are vulnerable to fuel leaks, as well as the creation of new fuel-line gaskets that are immune to significant swelling when they absorb gasoline. In their latest research, the Tuteja team demonstrated surfaces that effectively perform as “chemical shields against virtually all liquids, using a nanoscale coating that is approximately 95 percent air, which, in turn, repels liquids of any material in its class, causing them to literally bounce off the treated surface. This program is of particular interest to the Air Force and the DoD, as it can be useful for self-cleaning surfaces (in particular, integral breathable protective chemical/biological warfare defense in uniform clothing and sensor systems), improvement of thermal management efficiency in phase change cooling systems, fuel purification, and the control of oil and fuel leakages in rockets and airplanes. Not to mention protection against the everyday coffee spill.98
Transparent Transistors (2005-2009) AFRL scientists have demonstrated world-record performance of transparent transistors created from thin-film nanocrystalline zinc oxide, which can function, undetected, on clear surfaces such as glass or plastic. Lead investigator Dr. Burhan Bayraktaroglu of AFRL's Sensors Directorate and his team are responsible for developing and testing these transparent transistors under support from AFOSR. A combination of high channel mobility, mechanical flexibility, and high optical transparency at room temperature make the transparent transistors excellent candidates to support a wide range of future Air Force electronics needs and applications. Dr. Kitt Reinhardt, the initial AFOSR Program Manager for this effort, said potential applications include: video image displays and coatings for windows, visors, and windshields; electrical interconnects for future integrated multimode, remote sensing, focal plane arrays; high-speed
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