Patent ID: 8205497

Claim:
A micro electromechanical (MEM) inertial sensor, comprising: a substrate; a bridge which extends across an opening formed through the substrate; a proof mass located in the opening and formed, at least in part, from the substrate; a pivot located between the proof mass and the bridge to support the proof mass at a midpoint of the bridge; at least one transmission grating located proximate to the proof mass near an outer edge thereof; at least one, each laser corresponding to one of the at least one transmission grating to provide light which is transmitted through the one corresponding transmission grating and reflected off of a surface of the proof mass to generate a diffracted light pattern which changes with a movement of the proof mass in response to a sensed acceleration directed along a z-axis perpendicular to the substrate or at an angle to the z-axis; and at least one plurality of photodetectors, each plurality of photodetectors located proximate to one of the at least one laser to detect the diffracted light pattern corresponding to that laser and to generate electrical output signals to provide an indication of the sensed acceleration.