A novel method for fatigue testing of MEMS devices containing movable elements

TL;DR

This paper introduces an electronic circuit that estimates the position or capacitance of MEMS electrostatic actuators using a switched capacitor technique, enabling sensing without additional sensors.

Contribution

It presents a novel capacitive divider circuit that allows for actuation and sensing of MEMS devices without extra sensing elements, compatible with analog feedback and digital oscillators.

Findings

Effective position estimation of MEMS actuators achieved

Circuit is compatible with existing analog and digital systems

Potential for simplified MEMS device integration

Abstract

In this paper we present an electronic circuit for position or capacitance estimation of MEMS electrostatic actuators based on a switched capacitor technique. The circuit uses a capacitive divider configuration composed by a fixed capacitor and the variable capacitance of the electrostatic actuator for generating a signal that is a function of the input voltage and capacitive ratio. The proposed circuit can be used to actuate and to sense position of an electrostatic MEMS actuator without extra sensing elements. This approach is compatible with the requirements of most analog feedback systems and the circuit topology of pulsed digital oscillators (PDO).