Micromechanical electrostatic voltmeter

The prototype for a microminiature, noncontacting electrostatic voltmeter (ESV) is discussed. The ESV works on the principle of intermittent shuttering and exposing a sensing electrode to an electric field between a remote electrode at a different potential from the sensing electrode. The resultant time-varying field at the electrode produces an electrical signal which can be used to monitor the remote voltage. The prototype ESVs hat have been made and tested have electrostatic-comb drives and shutters with areas ranging from 0.022 to 0.067 mm/sup 2/ that are suspended roughly 2 mu m above the surface of the silicon substrate. Initial tests on ESVs showed them to respond to voltages above 20 V for electrodes spaced 0.2 mm away. Sensitivity is expected to be greatly improved by redesigns that are already being investigated.<>