Comment by sowbug

There's one basic question I couldn't figure out from the article. Where is the spring that you wind up and that stores the "power reserve of about 60 hours"? Is it part of the silicon? Or is it external? I figured out that the three crescent-shaped parts are springy ("flex laterally to provide a restoring force as the oscillator vibrates through six degrees of amplitude"), but it doesn't look like there's anything else that could stretch/relax over 60 hours. My sense of intuition is useless, of course, at this scale and with these materials.