A flexure based guidance system for precision motion control includes a base that is fixed in position, a carriage that can move relative to the base, an actuator provides the force to move the carriage relative to the base, and one or more flexures arrays that each comprise two or more leaf flexure elements. The actuator causes the carriage to move relative to the base, which causes the flexure elements in the flexure array to flex. The leaf flexure elements are thin, compliant and deform, bend, or deflect in a deterministic manner when mechanically stressed. In some embodiments, stiffeners can be added to the flexures. The guidance system can be integrated into a varifocal head mounted display (HMD) to adjust a location of one or moveable elements in an optical system of the HMD to control a location of an image plane.

The present invention discloses a micro-electro-mechanical system silicon on insulator (MEMS SOI) pressure sensor and a method for preparing the same. The pressure sensor includes a bulk silicon layer, a buried oxide layer, a substrate, a varistor, a passivation layer, and an electrode layer. The varistor is obtained by means of photolithography and ion implantation on a device layer of an SOI wafer. The passivation layer is SiO.sub.2 formed by means of annealing treatment on the SOI wafer. An annealing atmosphere is one of pure O.sub.2, a gas mixture of O.sub.2/H.sub.2O, a gas mixture of O.sub.2/NO, a gas mixture of O.sub.2/HCl, and a gas mixture of O.sub.2/CHF.sub.3. By means of the annealing treatment, the damage to a surface of the buried oxide layer as a result of over-etching during formation of the varistor by means of photolithography is eliminated and the unstability of the sensor caused by body and interface defects of the passivation layer and trapped charges thereof is resolved. A trench is formed at the buried oxide layer and the bulk silicon layer directly below the varistor, which helps overcome defects as a result of doped impurities entering the buried oxide layer below the varistor, and helps improve the sensitivity of the sensor.

A capacitive sensor includes a first conductive structure; a second conductive structure movable relative to the first conductive structure in response to an external force acting thereon, wherein the first and the second conductive structures form a first capacitor having a first capacitance that changes with a change in a distance between the first conductive structure and second conductive structure, wherein the first capacitance is representative of the external force; and a diagnostic circuit configured to detect a first leakage current in the capacitive sensor by measuring an first electrical parameter that is affected by the first leakage current and comparing the measured first electrical parameter to a first predetermined error threshold, wherein the diagnostic circuit is further configured to generate a first error signal in response to the measured first electrical parameter being greater than the first predetermined error threshold.

An MEMS microphone is provided, comprising a substrate and a vibration diaphragm supported above the substrate by a spacing portion, the substrate, the spacing portion, and the vibration diaphragm enclosing a vacuum chamber, and a static deflection distance of the vibration diaphragm under an atmospheric pressure being less than a distance between the vibration diaphragm and the substrate, wherein: a lower electrode forming a capacitor structure with the vibration diaphragm is provided on the substrate, and an electret layer providing an electric field between the vibration diaphragm and the lower electrode is provided on the substrate

A micromechanical sensor device and manufacturing method. The micromechanical sensor device is provided with a cap substrate, which has a first front side and a first back side, and which has a through-opening as a media entry region; and with a sensor substrate, which has a second front side and a second back side, and which has, on the second front side, a sensor region that is embedded in an island-like region suspended on the remaining sensor substrate. The island-like region is mechanically decoupled from the remaining sensor substrate by a lateral stress-relief trench and by a cavity situated in the sensor substrate, underneath the island-like region. The first back side is bonded to the second front side so that the through opening is situated above the sensor region. The sensor region is covered by a gel, which fills the through-opening and the stress-relief trench at least partially.

The disclosure describes a z-axis gyroscope where a proof mass is suspended from a peripheral suspender and a central suspender. The peripheral suspender forms a truncated triangle around the proof mass, and the central suspender extends through the truncated corner of the triangle formed by the peripheral suspender. The proof mass is driven into a primary oscillation mode by one or more piezoelectric drive transducers located on the peripheral suspender. One or more piezoelectric sense transducers located on the base of the peripheral suspender are configured to detect the secondary oscillation mode of the proof mass.

Described herein are accelerometers, apparatus and systems incorporating accelerometers, and techniques for controlling sensing operations in an accelerometer. In certain embodiments, an accelerometer is a microelectromechanical systems (MEMS) device including a proof mass, an anchor, a spring between the proof mass and the anchor, a drive electrode, and a sense beam. The anchor is located in an opening defined by a body of the proof mass. The spring and the proof mass form a spring system suspended from the anchor. The sense beam is configured to oscillate at a particular resonance frequency that changes according to a force generated by movement of the proof mass in response to acceleration. In some embodiments, a support structure couples the anchor to the spring and operates as a stress decoupling area that prevents or limits propagation of stress from the anchor to the sense beam and the spring system.

Disclosed herein are embodiments of a mass flow control apparatus, systems incorporating the same, and methods using the same. In one embodiment, a mass flow control apparatus comprises a flow modulating valve configured to modulate gas flow in a gas flow channel, a sensor device, such as a micro-electromechanical (MEMS) device, configured to generate a signal responsive to a condition of the gas flow, and a processing device operatively coupled to the flow modulating valve and the sensor device to control the flow modulating valve based on a signal received from the sensor device.

A sensor element includes a piezoelectric body, a plurality of excitation electrodes, and a plurality of detecting electrodes. The piezoelectric body includes a frame and a driving arm and detecting arm which extend from the frame within a predetermined plane parallel to an xy plane in an orthogonal coordinate system xyz. The excitation electrodes are located on the driving arm. The detecting electrodes are located on the detecting arm enabling detection of a signal generated by bending deformation of the detecting arm in a z-axis direction. The detecting arm includes first and second arms. The first arm extends from the frame in the predetermined plane. The second arm extends from a front end side of the first arm toward a frame side within the predetermined plane. An end part of the second arm on the frame side is formed as a free end.

An optical scanning device comprises a scanning structure, an anchor, and a drive unit. The drive unit includes a first drive unit and a second drive unit. The first drive unit includes a first drive beam, an electrode interconnect, paired supports, and a thin film magnet. The first drive beam has a first fixed end connected to the support and a first drive end connected to the scanning structure. The electrode interconnect is formed on the first drive beam. The supports are connected to the anchor and disposed to sandwich the first drive beam. The thin film magnet is disposed on each of the supports. The thin film magnet is disposed in such a manner that a magnetic line of force is generated in a direction intersecting a direction in which the electrode interconnect extends.