A self-resonant MEMS-based electrostatic field sensor

An electric-field sensor is presented for applications such as xerography. The sensor combines a vibrating MEMS structure with synchronous-detection electronics. The sensor architecture has three major blocks: a MEMS shutter, a sense interface, and a self-resonant drive loop that feeds back to the MEMS shutter. The self-resonant feedback loop is the enabling technology that provides the improved performance reported here. Prototyped in the iMEMS3 process at Analog Devices, the noise floor is 4.0 V/m/radic(Hz) and the integral nonlinearity is 20 V/m over a range of plusmn700 kV/m, which is an order-of-magnitude improvement over existing MEMS devices