An inertia measurement device, which is used in combination with a satellite positioning receiver that outputs a positioning result at every T seconds in a positioning system equipped on a vehicle, when a Z-axis angular velocity sensor, a position error P[m] based on the detection signal of the Z-axis angular velocity sensor while the vehicle moves at a moving speed V[m/sec] for T seconds satisfies Pp ≥ P = (V/Bz) × (1 - cos (Bz×T) ) (where, a bias error of the Z-axis angular velocity sensor is Bz[deg/sec] and a predetermined allowable maximum position error during movement for T seconds is Pp[m]), and a bias error Bx and By of the Y-axis angular velocity sensor satisfies Bz < Bx and Bz < By.

A method for forming a MEMS structure for an inertial sensor from fused silica includes: depositing a conductive layer on one or more selected regions of a first surface of a fused silica substrate, and illuminating areas of the fused silica substrate with laser radiation in a pattern defining features of the MEMS structure for an inertial sensor. A masking layer is deposited at least on the one or more selected regions of the first surface of the fused silica substrate where the conductive layer has been deposited, such that the illuminated areas of the fused silica substrate remain exposed. A first etch of the exposed areas of the fused silica substrate is performed so as to selectively etch the pattern defining features of the MEMS structure for an inertial sensor.

Method for manufacturing a micro-electro-mechanical system, MEMS, integrating a first MEMS device and a second MEMS device. The first MEMS device is a capacitive pressure sensor and the second MEMS device is an inertial sensor. The steps of manufacturing the first and second MEMS devices are, at least partly, shared with each other, resulting in a high degree of integration on a single die, and allowing to implement a manufacturing process with high yield and controlled costs.

An oscillator drive circuit and a trim circuit are implemented inside an integrated circuit of a sensor. The drive circuit provides an oscillating drive signal at a resonant frequency to drive a movable mass of the sensor. The drive circuit includes a phase shift circuit having an input for receiving a first signal indicative of an oscillation of the movable mass and having an output. The phase shift circuit adds a phase shift component to the first signal and produces a second signal shifted in phase by the phase shift component. The trim circuit includes a first comparator for receiving the first signal, a second comparator for receiving the second signal, and a processing element. The processing element determines a phase lag between the first and second signals and produces trim code for use by the phase shift circuit, the trim code being configured to adjust the phase shift component.

The invention relates to a method of fabricating a micro machined channel, comprising the steps of providing a substrate of a first material and having a buried layer of a different material therein, and forming at least two trenches in said substrate by removing at least part of said substrate. Said trenches are provided at a distance from each other and at least partly extend substantially parallel to each other, as well as towards said buried layer. The method comprises the step of forming at least two filled trenches by providing a second material different from said first material and filling said at least two trenches with at least said second material; forming an elongated cavity in between said filled trenches by removing at least part of said substrate extending between said filled trenches; and forming an enclosed channel by providing a layer of material in said cavity and enclosing said cavity.

A headphone and an electronic device are provided. The headphone includes a gyroscope, which senses a bone conduction vibration and provides a quadrature error signal for reflecting the bone conduction vibration. Specifically, the headphone includes a transmission assembly that acts directly or indirectly on the gyroscope or an inertial measurement unit (IMU) including the gyroscope. The transmission assembly transmits the bone conduction vibration to the gyroscope to make the gyroscope strain, thereby causing the quadrature error signal of the gyroscope to change to detect the bone conduction vibration with sensitivity.

Inertial measurement apparatus arranged to be carried by a carrier vehicle include a chassis, a turntable mounted on the chassis, a first inertial measurement unit mounted on the turntable and connected to an electronic control unit connected to a motor for controlling turning of the turntable, and a second inertial measurement unit secured to the chassis. The control unit turns the turntable through one revolution with periodic alternating motion from a fixed initial angular position of the turntable. The control unit calculates the acceleration of the carrier vehicle from measuring the first inertial measurement unit while the turntable is stationary and from measuring the second inertial measurement unit while the turntable is moving. The control unit reconstitutes an inertial reference frame for each inertial measurement unit and compares the two inertial reference frames to determine a difference and takes account of this difference when calculating the acceleration.

Methods and systems for reducing stiction through roughening the surface and reducing the contact area in MEMS devices are disclosed. A method includes fabricating bumpstops on a surface of a MEMS device substrate to reduce stiction. Another method is directed to applying roughening etchant to a surface of a silicon substrate to enhance roughness after cavity etch and before removal of hardmask. Another embodiment described herein is directed to a method to reduce contact area between proof mass and UCAV (“upper cavity”) substrate surface with minimal impact on the cavity volume by introducing a shallow etch process step and maintaining high pressure in accelerometer cavity. Another method is described as to increasing the surface roughness of a UCAV substrate surface by depositing a rough layer (e.g. polysilicon) on the surface of the substrate and etching back the rough layer to transfer the roughness.

In a method for manufacturing a micro vibration body having a three-dimensional curved surface, a mold defining a recess part is prepared, and a plate-shaped reflow material is arranged on the mold so as to cover the recess part. Pressure of a space defined by the recess part covered with the reflow material is reduced, and the reflow material is deformed by heating from an upper surface side opposite to a lower surface facing the recess part and by means of the pressure reduced. When the reflow material is deformed, a part of the mold is heated and / or cooled. As another example, when the reflow material is deformed, a mold having a different heat capacity portion is used to generate a temperature gradient in the mold.

Methods for fabricating MEMS tuning fork gyroscope sensor system using silicon wafers. This provides the possibly to avoid glass. The sense plates can be formed in a device layer of a silicon on insulator (SOI) wafer or in a deposited polysilicon layer in a few examples.