At the end of my blog post about laser gryoscopes, I mentioned that pretty much every smartphone now has microelectromechanical (MEMS) gryoscopes or accelerometers inside its case, and that too was development funded by the US Department of Defense. It was pretty much a throwaway observation about I which knew nothing more, so it was very neat to see a whole chapter on government funding for MEMS in a new book from NASA, Historical Studies in the Societal Impact of Spaceflight.
As the chapter’s author, Andrew J. Butrica, explains, a lot of the early research into MEMS was done at and around Stanford University and its Integrated Circuits Laboratory in the 70s. One of the lab’s partners and funders was NASA’s Ames Research Center, whose interest was mainly in the opportunities to use MEMS instruments in biomedical research. Another was the National Institutes of Health, also interested in medical research, which put more than a million dollars a year into the Integrated Circuits lab. A third, and one who had been funding electronics research at Stanford since the 1940s, was the military’s Joint Services Electronics Program. The first MEMS accelerometer, described in a 1977 dissertation by Stanford electrical engineering student Lynn Michael Roylance, was funded for its first two years of development by the Joint Services Electronics Program and in part thereafter by a NASA grant.
What happened next would have seemed really weird if I didn’t already know about the winding path towards military use that the laser gyroscope took. One of the earliest widespread adopters of MEMS sensors was the automotive industry, which used MEMS pressure sensors to measure the air pressure in engine manifolds, MEMS accelerometers to trigger airbags in case of sudden deceleration, and MEMS gyroscopes to guide anti-skid and rollover detection systems. Automobile manufacturers liked MEMS sensors for their small size and reliability, which also made them good for use in guided munitions. Starting in 1990 or so, when the global market for MEMS devices had grown to $480 million (according to the March 1, 1993 issue of Aviation Week and Space Technology), development came full circle and MEMS sensors started turning up in weapons. A quartz tuning fork gyro was integrated into the Maverick anti-tank missile in 1990, while in 1995–6 automotive-grade MEMS components were used to build a prototype guided shell, the Extended-Range Guided Munition (ERGM), for the US Navy.
Interestingly, the sensors in the ERGM were built by Draper Labs, better known for designing extremely precise gryos and accelerometers for use in intercontinental ballistic missiles, who had used an initial government-funded investment in MEMS development to enter the automotive MEMS sensor market. (There’s a lot of good information on those developments, much of it written by Draper Labs staff, in this NATO paper collection.)
Obviously, the use of MEMS in cars and commercial electronics (like the Nintendo Wii and Apple iPhone) were not the only factor in continuing development. From 1992 on, the Defense Advanced Research Projects Agency (DARPA) invested in MEMS research through its Microsystems Technology Office. So did national labs like Sandia, and presumably many others – I’m sure I still only know a small slice of what was going on with MEMS in these years. Still, it’s interesting to see another case of what still strikes me as surprising – development coming full circle from speculative military research through commercialization to practical military use.