REDUCING THERMO-ELASTIC DAMPING OF MEMS RESONATORS USING A VIRTUAL SPRING

We report on a MEMS resonator that can reduce thermo-elastic damping (TED) and increase the quality factor beyond the conventional TED limit. The TED reduction is attained by a virtual spring, which is a spring-like actuator enabled by electrostatic actuators. In the virtual spring, the restoring force is realized by applying position-dependent voltages to the actuator. In contrast to mechanical springs, the actuator shape is unchanged during the actuation. This enables to reduce the stress and hence the TED. We show by simulations that the quality factor can be increased by a factor of 30, compared to a reference mechanical resonator with the same resonance frequency. We also report on the structure dependence of the virtual spring quality factors.