US Patent 7204162 Capacitive strain gauge

A strain gauge for sensing strain is provided and includes a support substrate, and first and second electrodes supported on the substrate. The first and second electrodes include first and second capacitive plates, respectively. The first capacitive plates are movable relative to the second capacitive plates responsive to strain. The strain gauge further has an input electrically coupled to one of the first and second electrodes for receiving an input signal, and an output electrically coupled to the other of the first and second electrodes for providing an output signal which varies as a function of the capacitive coupling and is indicative of sensed strain.