On the quality of quality-factor in gap-closing electrostatic resonators

We present analytic expressions for three common measures of the dynamic response in gap-closing electrostatic resonators. We show that peak gain, peak sharpness and logarithmic decrement are distinctively different and are not equal to the quality-factor of the unloaded system. We experimentally validate our theoretical predictions by characterizing the dynamic response of test devices. The significance of this work is that it clarifies the correct way in which the performance of MEMS resonators should be reported to avoid ambiguity.