Torsional Moving Electric Field Sensor with Modulated Sensitivity and without Reference Ground

Abstract

A MEMS electric field sensor is presented with wide measurement resolution and adjustable sensitivity. The sense membrane is mounted using torsional springs and employs opposite biased electrodes on its surface, causing rotation in presence of an electric field, enabling operation without reference ground. Control of electrode bias enables adjustable linear measurement range from V/m to MV/m. Compared to earlier works with vertical moving sense membranes, higher sensitivity is achieved for the same bias voltage. Employing on-board electronics to enable independent resonant operation, a noise limited resolution of 3 V/m was achieved.

Keywords

• MEFM
• electric field
• electric field measurement
• electric field mill
• MEMS