High sensitivity single-axis MEMS accelerometer with bilateral flexures

An apparatus comprising:

• a proof mass;
• a first set of flexures on a top side of the apparatus;
• and
• a second set of flexures on a bottom side of the apparatus,
• wherein the first set of flexures is a bilateral set of flexures, the second set of flexures is a bilateral set of flexures, and the first and second sets of flexures each include at least one diametrically opposed pair of flexures,
• wherein the first set of flexures is arranged symmetrically with respect to the second set of flexures,
• wherein the first and second sets of flexures are configured to allow the proof mass to move along a first axis and restrict motion of the proof mass along second and third axes perpendicular to the first axis, and
• wherein a portion of the proof mass juts out along at least one of the second and third axes between opposing ones of the first set of flexures and the second set of flexures.

A microelectromechanical accelerometer for sensing acceleration along a z axis, comprising:

• a frame;
• a proof mass;
• a first set of flexures on a top side of the microelectromechanical accelerometer;
• a second set of flexures on a bottom side of the microelectromechanical accelerometer;
• and
• a plurality of electrodes,
• wherein the first set of flexures is a bilateral set of flexures, the second set of flexures is a bilateral set of flexures, and the first and second sets of flexures each include at least one diametrically opposed pair of flexures,
• wherein the first set of flexures is arranged symmetrically with respect to the second set of flexures,
• wherein each flexure is anchored to the frame at a first end of each flexure and connected to the proof mass at a second end of each flexure,
• wherein a first portion of the proof mass juts out in a plane orthogonal to the z axis between opposing ones of the first set of flexures and the second set of flexures,
• wherein a second portion of the proof mass juts out in the plane orthogonal to the z axis between opposing electrodes of the plurality of electrodes,
• wherein the proof mass is displaced along the z axis in response to at least one of a voltage applied between the opposing electrodes and a first external acceleration along the z axis, and
• wherein the first and second sets of flexures are arranged such that a second external acceleration in the plane orthogonal to the z axis places at least some of the flexures in tension and at least some others of the flexures in compression.