Electro-mechanical chopping & modulation of acceleration: The geometry-modulated accelerometer

This paper reports, to the authors' knowledge, the first MEMS accelerometer capable of modulating the acceleration signal from DC to AC frequencies: the geometry-modulated accelerometer. In this innovative scheme of operation, the geometry of the movable mass is changed during operation by means of electrostatic actuation, resulting in the modulation of the moment of inertia and thus of the inertial force. A first prototype of an in-plane geometry-modulated accelerometer having -0.3 fF/g sensitivity for an in-plane area of about (500 μm × 500 μm) is presented and demonstrated.