Modeling the Electromechanical Properties of the MEMS Element of a Thermoelectric Infrared Sensor Based on the Dynamic Seebeck Effect

In this work, we studied the electromechanical properties of the MEMS (micro-electro-mechanical system) element of an infrared (IR) sensor with nanoscale switchable thermocouples for two promising types of its design, depending on the geometry of the electrodes on a square dielectric membrane, controlling its electrostatic displacement - when they are placed on opposite sides of the membrane (design 1) and along its perimeter (design 2), respectively. From the simulation it follows that the threshold voltage corresponding to the contact of the surface of the membrane and the bottom of the cavity in the substrate, as a result of which the heat accumulated in the membrane by IR radiation is dissipated and the microsystem is switched, is almost 5 times lower for the second design of MEMS element than for the first one. It makes the second design more promising not only in terms of energy consumption, but also speed, due to the larger contact area of the membrane with the heat-conducting layer, which reduces the reset time required to return the MEMS element to its original state. The results obtained can be used to create a new generation of matrix photodetector devices operating in the infrared range.