High precision electrostatic MEMS actuators for in-plane Fabry-Pérot gas sensors

This paper is dedicated to the design, fabrication and characterization of MEMS electrostatic actuators. Two types of electrostatic MEMS actuators are described in detail: The first is a digital (8-bit) actuator, with bit-by-bit control of voltage and displacement. It is concepted for a linear drive characteristic, a large travel range of up to 4 μm with a driving voltage of less than 30 V. The second analogue actuator is designed to operate with the same driving voltage, has a smaller travel range (about 1.5 μm), however has a built-in capacitive displacement sensor. Both actuators are designed to precisely control a MEMS optical sensor, part of a MEMS-based, highly miniaturised and mobile spectrometer for the analysis of gases and gas mixtures.