Experimental Technique

1
Experimental Technique
Driving

• Bias voltage applied to the suspended structure
  and ground plane to increase the force applied by
  comb drives and reduce out-of-plane levitation
• 180 phase shift allows for each side of the comb
  drive to take turns pulling the suspended
  structure

Sensing

• Higher frequency carrier signal used to sense
  movement
• The current through DC bias is measured and with
  demodulation and filtering, the magnitude of the
  signal can be found (separate from the applied
  signal) therefore determining the magnitude of
  the rotation.

2
Non-linear Response of Resonators
Resonance Profiles at Varying Pressure

• Devices are run in vacuum environment where
  nonlinear response is observed.
• The diagram shows the transition with pressures
  ranging from 150 Torr to 36 mTorr
• Hard to pinpoint exact resonance frequency at
  higher pressures because of the wide resonance
  peak.
• When testing, devices were approached from below
  the resonance frequency and raised until the
  desired amplitude was obtained.

Pressure (Torr)