An accelerometer comprising a first proof mass and a second proof mass which are coupled to each other with a coupling structure which extends from the first proof mass to the second proof mass. The coupling structure synchronizes the movement of the first and second proof masses so that the first and second proof masses may be linearly displaced from their rest position in the x-direction, rotationally displaced in opposite in-plane directions and rotationally displaced in opposite out-of-plane directions.

An accelerometer for measuring acceleration in the direction of a z-axis which is perpendicular to an xy-plane, where a first proof mass is suspended from a first side anchor point with a first suspension structure which allows the first proof mass to undergo rotation about a first rotation axis. A second proof mass is suspended from a second side anchor point with a second suspension structure. The second suspension structure allows the second proof mass to undergo rotation about a second rotation axis. The torsion elements in the first and second suspension structure lie further away from the center of the accelerometer than the corresponding side anchor points from which the masses are suspended.

A microelectromechanical accelerometer for measuring acceleration, comprising a first proof mass and ae second proof mass. The first proof mass is adjacent to the second proof mass. A suspension structure allows the first proof mass to undergo rotation out of the device plane about a first rotation axis and the suspension structure allows the second proof mass to undergo rotation out of the device plane about a second rotation axis. The first and second rotation axes are parallel to each other and define an x-direction which is parallel to the first and the second rotation axes and a y-direction which is perpendicular to the x-direction. The y-coordinate of the first rotation axis is greater than the y-coordinate of the second rotation axis by a nonzero distance D.

A microelectromechanical systems (MEMS) accelerometer comprises a compliant spring structure with a first beam, a second beam, and a rigid structure. One end of the first beam and one end of the second beam are coupled to the rigid structure and a proof mass is coupled to another end of the second beam. Further, a spring anchor is coupled to another end of the first beam. In response to the proof mass moving, an extension coupled to the rigid structure moves in an opposite direction to motion of the proof mass to contact the proof mass and stop the movement of the proof mass.

An inertial sensor includes a substrate, a first supporting beam being a first rotation axis extending along a first direction, a first movable member swingable around the first rotation axis, a second supporting beam being a second rotation axis extending along a second direction crossing the first direction, a second movable member swingable around the second rotation axis, a third rotation axis extending along a second direction, a third movable member swingable around the third rotation axis, and a projection, wherein the second and third movable members are line-symmetrically placed with a center line of the first movable member along the second direction as an axis of symmetry, a center of gravity of the second movable member is closer to the center line than the second supporting beam, and a center of gravity of the third movable member is closer to the center line than the third supporting beam.

An inertial sensor includes a substrate, a first supporting beam being a first rotation axis extending along a first direction, a first movable member swingable around the first rotation axis, a second supporting beam being a second rotation axis extending along a second direction crossing the first direction, a second movable member swingable around the second rotation axis, a third rotation axis extending along a second direction, a third movable member swingable around the third rotation axis, and a projection, wherein the second and third movable members are line-symmetrically placed with a center line of the first movable member along the second direction as an axis of symmetry, a center of gravity of the second movable member is closer to the center line than the second supporting beam, and a center of gravity of the third movable member is closer to the center line than the third supporting beam.

A microelectromechanical systems (MEMS) accelerometer comprises a compliant spring structure with a first beam, a second beam, and a rigid structure. One end of the first beam and one end of the second beam are coupled to the rigid structure and a proof mass is coupled to another end of the second beam. Further, a spring anchor is coupled to another end of the first beam. In response to the proof mass moving, an extension coupled to the rigid structure moves in an opposite direction to motion of the proof mass to contact the proof mass and stop the movement of the proof mass.

Described herein are accelerometers, apparatus and systems incorporating accelerometers, and techniques for electrostatically adjusting a stiffness of a spring system in an accelerometer. Embodiments featuring resonant and/or quasi-static accelerometers are described. In certain embodiments, an accelerometer is a microelectromechanical systems (MEMS) device including a proof mass, an anchor, a spring attached to the proof mass, a sense electrode, and a tuning electrode. The spring and the proof mass form a spring system suspended from the anchor. The sense electrode is configured to generate a signal indicating movement of the proof mass based on application of a first signal. The tuning electrode is configured to receive an electrostatic tuning signal, the electrostatic tuning signal being separate from the first signal and providing a negative contribution to an overall stiffness of the spring system. The electrostatic tuning signal can be used to adjust the stiffness based on a measured acceleration.

A microelectromechanical systems (MEMS) accelerometer comprises a compliant spring structure with a first beam, a second beam, and a rigid structure. One end of the first beam and one end of the second beam are coupled to the rigid structure and a proof mass is coupled to another end of the second beam. Further, a spring anchor is coupled to another end of the first beam. In response to the proof mass moving, an extension coupled to the rigid structure moves in an opposite direction to motion of the proof mass to contact the proof mass and stop the movement of the proof mass.

The present disclosure discloses a vertical superconducting magnetic mass-spring oscillator with an adjustable natural frequency, comprising: a proof mass, a negative-stiffness superconducting coil and a positive-stiffness superconducting coil; the negative-stiffness superconducting coil is mounted at an opening of a semi-closed space of the proof mass, so that a part of magnetic lines of the negative-stiffness superconducting coil are in a compressed state in a closed space of the proof mass, and the other part of the magnetic lines of the negative-stiffness superconducting coil are in an expanded state outside the closed space of the proof mass; a vertical magnetic repulsive force applied to the proof mass by the negative-stiffness superconducting coil varies with a displacement of the proof mass from an equilibrium position, with the variation magnitude proportional to the displacement and the variation direction the same as the displacement direction; and the positive-stiffness superconducting coil is mounted in the semi-closed space of the proof mass, and a vertical magnetic repulsive force applied to the proof mass by the positive-stiffness superconducting coil varies proportionally to the displacement of the proof mass from the equilibrium position, with the variation direction opposite to the displacement direction. The present disclosure realizes that the natural frequency of the superconducting mass-spring oscillator is adjustable, and meanwhile, the cross-coupling effect of horizontal and vertical degrees of freedom of the proof mass can be reduced.