MEMS and sensors

What is the damping called that arises when a MEMS movable plate moves toward a nearby fixed surface and squeezes out the gas between them?

  1. ADielectric relaxation
  2. BSqueeze-film damping
  3. CCoulomb friction
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Answer: B. Squeeze-film damping

When the gap between a movable plate and a fixed surface is narrow, gas is pushed out and drawn in with each movement, creating large viscous resistance. This is called squeeze-film damping. It is used to tune accelerometer response but lowers the Q of resonators. It is adjusted with perforation holes or by sealing in vacuum.

  • A. Dielectric relaxation is the delayed response of polarization in a dielectric.
  • B. Correct. It is damping from gas flowing in and out of the gap.
  • C. Coulomb friction is solid friction at contacting surfaces.
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