A microelectromechanical element is provided that includes a first device part and a second device part, and a motion-limiting structure having a first stopper bump and a second stopper bump. The first and second stopper bumps extend from the first device part toward the second device part. When one of the device parts moves toward the other device part in the out-of-plane direction and crosses a displacement threshold, the first stopper bump comes into contact with the second device part before the second stopper bump contacts the second device part, and the second stopper bump comes into contact with the second device part before the first device part contacts with the second device part.

An accelerometer includes a controller, a light source operatively coupled to the controller, and a bifurcated waveguide coupled to the light source and configured to receive light output by the light source. The bifurcated waveguide includes a first waveguide portion and a second waveguide portion. The accelerometer also includes a first resonator operatively coupled to the controller and configured to receive light from the first waveguide portion, and a second resonator operatively coupled to the controller and configured to receive light from the second waveguide portion. The first resonator includes a first proof mass, and the second resonator includes a second proof mass.

A microelectromechanical systems (MEMS) accelerometer that has high sensitivity to motion along the z axis is discussed. The device includes two symmetrical sets of bilateral, diametrically opposed high aspect ratio flexures that tether a movable proof mass to the frame of the device. The flexures are designed in such a way as to restrict movement of the proof mass along the x and y axes but readily allow motion along the z axis. More specifically, when the device experiences an acceleration along the x or y axes, the proof mass is restricted from moving because some of the bilateral, diametrically opposed flexures are in compression and others are in tension.

The invention is directed at an optical sensor device, comprising a sensing element for receiving an input action, an optical fiber comprising an intrinsic fiber optic sensor, and a transmission structure arranged for exerting a sensing action on the optical fiber in response to the input action received by the sensing element, wherein the optical fiber in a first connecting part thereof is connected to a reference body and wherein the optical fiber in a second connecting part thereof is to the transmission structure for receiving the sensing action, the first connecting part and the second connecting part of the optical fiber being located on either side of the intrinsic fiber optic sensor, wherein the transmission structure comprises a bi-stable spring having a first and a second stable deflection position and a negative stiffness range around an unstable equilibrium position between the first and second stable deflection position, and wherein the optical fiber between the transmission structure and the reference body is pre-stressed such as to be tensed, said optical fiber thereby acting as a spring having a first spring constant of positive value, wherein the optical fiber thereby counteracts a spring action of the bi-stable spring such as to operate the bi-stable spring in a deflection position range within the negative stiffness range, the deflection position range not including the unstable equilibrium position of the bi-stable spring.

An inertial sensor includes a proof mass spaced apart from a surface of a substrate. The proof mass has a first section and a second section, where the first section has a first mass that is greater than a second mass of the second section. An anchor is coupled to the surface of the substrate and a spring system is interconnected between the anchor and the first and second sections of the proof mass. The spring system enables translational motion of the first and second sections of the proof mass in response to linear acceleration forces imposed on the inertial sensor in any of three orthogonal directions.

Accelerometers as disclosed herein include a proof mass assembly and an accelerometer support. In some examples, a combined height and a combined coefficient of thermal expansion (CTE) of the materials of the accelerometer support is configured to substantially match a CTE of material of the non-moving member with a height substantially similar to the combined height of the accelerometer support. In some examples, the accelerometer support is configured to connect to a center raised pad of the proof mass assembly and maintain a capacitance gap between a capacitance plate on a proof mass of the proof mass assembly and a portion of the non-moving member.

An accelerometer includes a membrane, an energy source producing a laser beam which is directed at the membrane causing it to vibrate, and a transparent cap disposed at one end of the energy source. The accelerometer includes a first controller for adjusting an output power of the energy source in a first feedback loop, a second controller for controlling the wavelength of the laser beam in a second feedback loop, and a detector sensing a reflected portion of the laser beam. An acceleration signal is based in part on the frequency of the reflected portion of the laser beam.

An accelerometer includes a membrane; a laser source, the laser source producing a laser beam, the laser beam directed at the membrane causing the membrane to vibrate; a transparent cap, the transparent cap disposed between the laser source and the membrane; an antireflecting film disposed on an outer surface of the transparent cap; and a detector sensing a reflected portion of the laser beam, the reflected portion including a modulated intensity. An acceleration signal is based in part on the frequency of the modulated intensity of the reflected portion of the laser beam.

In a teeter-totter type MEMS accelerometer, the teeter-totter proof mass and the bottom set of electrodes (i.e., underlying the proof mass) are formed on a device wafer, while the top set of electrodes (i.e., overlying the teeter-totter proof mass) are formed on a circuit wafer that is bonded to the device wafer such that the top set of electrodes overlie the teeter-totter proof mass. The electrodes formed on the circuit wafer may be formed from an upper metallization layer on the circuit wafer, which also may be used to form various electrical connections and/or bond pads.

A sensor is disclosed. The sensor includes a substrate and a mechanical structure. The mechanical structure includes at least two proof masses including a first proof mass and a second proof mass. The mechanical structure also includes a flexible coupling between the at least two proof masses and the substrate. The at least two proof masses move in an anti-phase direction normal to the plane of the substrate in response to acceleration of the sensor normal to the plane and move in anti-phase in a direction parallel to the plane of the substrate in response to an acceleration of the sensor parallel to the plane. The at least two proof masses move in a direction parallel to the plane of the substrate in response to an acceleration of the sensor parallel to the plane.