A virtually floating dual-mass accelerometer

A novel microelectromechanical system (MEMS) for the measurement of acceleration is presented. It combines a new mechanical structure consisting of two masses with a novel readout principle. The differential-mode displacement of the two proof masses corresponds to the applied acceleration and is embedded in a force-feedback loop. A new readout circuit is presented to give a readout proportional to this differential-mode. In addition, this new readout circuit has a control mechanism to operate the common-mode displacement of this dual-mass structure at the pull-in point. This increases the mechanical and electrical sensitivity.As a proof of concept, a prototype was designed for the complete system. The accuracy of the system is 4.1μg/Hz, which corresponds to the mechanical noise floor of the mechanical structure.