Charge-drift elimination in resonant electrostatic MEMS

We present a biasing technique and a novel oscillator architecture for the elimination of frequency drifts in resonant electrostatic MEMS that are caused by the motion of charge present within dielectrics. We demonstrate more than two orders of magnitude improvement in stability for a test device operating as a frequency reference at 1.077 MHz, reducing frequency drift from more than 100 Hz over 3 hours using traditional actuation, down to less than 1.5 Hz variation over 40 hours using the new technique.