A key issue for sustainability of MEMS manufacturing is currently only aging fabs are being used. If a dedicated new fab were built, the returns may never be enough to justify in the bookkeeping. MEMS would need to be as ubiquitous as microprocessors or memory to justify this level of investment. In turn, that means MEMS production costs need to go down. This vicious cycle may not get off the ground in time.
As the sensors become inexpensive, they should be used in sensors to prevent injuries (and document accidents) in industry and sports, to assist the handicapped, and to augment existing devices. Airbags for football players, autofocus glasses for reading, external airbags on cars, or tactile feedback guidance devices for the blind. We ought to be looking at a broader scope for these technologies. In 20 years we'll be looking back and it will all seem so obvious.