Patent ID: 8505380

Claim:
A micro-electromechanical systems (MEMS) device comprising: a substrate; one or more stators fixedly attached to the substrate, the stators comprising a plurality of tines having a surface parallel to a surface of the substrate, wherein the tine surface is at a first distance from the surface of the substrate; and a proof mass rotatably attached to the substrate, the proof mass comprising: a first end; a second end; a middle section for connecting the first and second ends and for connecting to the substrate via flexural supports; one or more rotors, the rotors comprising a plurality of rotor tines attached to an edge of the first and second ends of the proof mass, the rotor tines being interleaved with corresponding ones of the stator tines, the rotor tines comprising a surface parallel to a surface of the substrate, wherein the rotor tine surface is at a second distance from the surface of the substrate, wherein the first distance and second distance are unequal by a threshold amount, wherein the first end has a greater mass than the second end, wherein the first distance is less than the second distance if a direction of a to-be-sensed acceleration is in a direction from the substrate to the tines, wherein the direction of the to-be-sensed acceleration is perpendicular to a major proof mass plane; wherein the first distance is greater than the second distance if a direction of the to-be-sensed acceleration is in a direction from the tines to the substrate, wherein the one or more stators comprise drive and sense stators and the one or more set of rotors comprise drive and sense rotors corresponding to the drive and sense stators, wherein the sense rotors extend from first and second edges of the proof mass at the first and second ends, the first and second edges face towards the middle section and are parallel to a rotational axis defined by the flexural supports, the first and second edges are equidistant from a centerline of the proof mass, the centerline of the proof mass is perpendicular to the rotational axis, wherein the drive rotors extend from third edges of the proof mass at the first and second ends, the third edges face away from the middle section and are parallel to a rotational axis defined by the flexural supports.