A microelectromechanical device comprising a mass, an electromechanical transducer configured to convert, after damping the mass during a first damping period, displacement of the mass in the first and second directions into corresponding first and second electrical signals during corresponding first and second conversion time periods, a derivative unit configured to generate first and second control signals indicative of the velocity of the mass in the first and second direction, and a controller for providing the first and second control signals to respective first and second one or more electrodes of the electromechanical transducer for simultaneously damping the mass in the first and second directions with a first and second damping forces corresponding to the first and second velocity during the damping time period.

The MEMS device is formed by a substrate and a movable structure suspended on the substrate. The movable structure has a first mass, a second mass and a first elastic group mechanically coupled between the first and the second masses. The first elastic group is compliant along a first direction. The first mass is configured to move with respect to the substrate along the first direction. The MEMS device also has a second elastic group mechanically coupled between the substrate and the movable structure and compliant along the first direction; and an anchoring control structure fixed to the substrate, capacitively coupled to the second mass and configured to exert an electrostatic force on the second mass along the first direction. The anchoring control structure controls the MEMS device in a first operating state, wherein the second mass is free to move with respect to the substrate along the first direction, and in a second operating state, wherein the anchoring control structure applies a pull-in force on the second mass which anchors the second mass to the anchoring structure.

Linear accelerometer comprising a fixed part, a rotationally moving part in the plane of the accelerometer around an axis of rotation orthogonal to the plane of the accelerometer, the moving part comprising a centre of gravity distinct from the point of intersection of the axis of rotation and the plane of the accelerometer, means forming pivot link between the moving part and the fixed part, means for detecting the displacement of the moving part with respect to the fixed part, means for viscous damping the displacement of the moving part in said plane, said viscous damping means comprising interdigitated combs, at least one first comb on the moving part and at least one second comb on the fixed part (2), the first comb and the second comb being interdigitated.

Embodiments of multi-frequency excitation are described. In various embodiments, a natural frequency of a device may be determined. In turn, a first voltage amplitude and first fixed frequency of a first source of excitation can be selected for the device based on the natural frequency. Additionally, a second voltage amplitude of a second source of excitation can be selected for the device, and the first and second sources of excitation can be applied to the device. After applying the first and second sources of excitation, a frequency of the second source of excitation can be swept. Using the methods of multi-frequency excitation described herein, new operating frequencies, operating frequency ranges, resonance frequencies, resonance frequency ranges, and/or resonance responses can be achieved for devices and systems.

Mechanical low pass filters for motion sensors and methods for making the same are disclosed. In an implementation, a motion sensor package comprises: a substrate; one or more viscous dampers formed on the substrate; one or more mechanically compliant metal springs formed on the substrate; and a sensor stack attached to the one or more metal springs, the sensor stack overlying the one or more viscous dampers and forming a gap between the sensor stack and the one or more viscous dampers and channels between the one or more viscous dampers and metal springs, wherein the one or more metal springs and the one or more viscous dampers provide a mechanical suspension system having a resonant frequency that is higher than a sensing bandwidth of a motion sensor in the sensor stack and lower than a resonant frequency of the motion sensor.

Mechanical low pass filters for motion sensors and methods for making same are disclosed. In some implementations, a motion sensor package comprises: a substrate; one or more mechanically compliant dampers formed on the substrate; one or more mechanically compliant metal springs formed on the one or more dampers and the substrate; and a sensor stack attached to the one or more metal springs, wherein the one or more metal springs and dampers provide a mechanical suspension system having a resonant frequency that is higher than a sensing bandwidth of a motion sensor in the sensor stack and lower than a resonant frequency of the motion sensor.

In one embodiment, a sensor includes a rigid wafer outer body. A first cavity is located within the rigid wafer outer body, and a first vibration isolating spring is supported by the rigid wafer outer body and extends into the first cavity. A second vibration isolating spring is supported by the rigid wafer outer body and extends into the first cavity, and a first sensor packaging is supported by the first vibration isolating spring and the second vibration isolating spring within the first cavity.

A physical quantity sensor includes a substrate, a support portion fixed to the substrate, a movable body which is displaceable in a first direction with respect to the support portion and has a movable electrode provided therein, and a fixed electrode fixed to the substrate. The fixed electrode includes first and second fixed electrode fingers positioned on one side of the support portion, third and fourth fixed electrode fingers positioned on the other side thereof. The movable electrode includes first to fourth movable electrode fingers which face the first to fourth fixed electrode fingers in the first direction, respectively.

A resonant sensor including a support, a proof body suspended from the support and having a resonant frequency ?a, an element that measures a force including at least one resonator of resonant frequency ?.sub.rn, the force being applied by the proof body, and a mechanical decoupling structure interposed between the proof body and the resonator. The decoupling structure includes a decoupling mass, a first connecting element between the decoupling mass and the proof body, a second connecting element between the decoupling mass and the resonator, the decoupling structure having a main vibration mode whose resonant frequency ?.sub.d is such that ?a<?.sub.d<?.sub.rn, the decoupling structure forming a mechanical low-pass filter between the proof body and the resonator.

A capacitive accelerometer including: at least one additional fixed capacitor electrode with a plurality of additional fixed capacitive electrode fingers extending along the sensing direction. The proof mass comprises a plurality of moveable capacitive electrode fingers extending from the proof mass along the sensing direction and arranged to interdigitate with the plurality of additional fixed capacitive electrode fingers of the at least one additional fixed capacitor electrode. A means is provided for applying a voltage to the at least one additional fixed capacitor electrode to apply an electrostatic force to the plurality of moveable capacitive electrode fingers that acts to pull the proof mass towards the at least one further fixed capacitor electrode and thereby reduces the lateral spacings between the movable capacitive electrode fingers of the proof mass and the first and second sets of fixed capacitive electrode fingers that provide electrostatic forces for sensing purposes.