Murata Manufacturing Co., Ltd.

Hannu Vesterinen

Matti Liukku

Anssi Blomqvist

Ville-Pekka Rytkönen

Jaakko Ruohio

The present invention relates to MEMS (microelectromechanical systems) accelerometers, in particular to an accelerometer designed to reduce error in the accelerometer output. The MEMS accelerometer includes a proof mass, which is capable of movement along at least two perpendicular axes and at least one measurement structure. The proof mass is mechanically coupled to the measurement structure along the sense axis of the measurement structure, such that movement of the proof mass along the sense axis causes the moveable portion of the measurement structure to move, and is decoupled from the measurement structures along an axis or axes perpendicular to the sense axis of the measurement structure, such that movement of the proof mass perpendicular to the sense axis of the measurement structure does not cause the moveable portion of the measurement structure to move.

MEMS accelerometer with mechanically decoupled proof mass

The present invention provides a high-accuracy low-noise MEMS accelerometer by using a larger, single proof mass to measure acceleration along two orthogonal axes. A novel arrangement of electrodes passively prevents cross axis error in the acceleration measurements. Novel arrangements of springs and a novel proof mass layout provide further noise reduction.

Low-noise multi axis MEMS accelerometer

A capacitive micromechanical accelerometer comprising a first proof mass, a second proof mass, a third proof mass and a fourth proof mass. Each proof mass is configured as a seesaw which undergoes rotation out of the xy-plane in response to z-axis acceleration. The four proof masses are suspended from the same central anchor point with torsionally flexible suspension arrangements. Errors introduced into the output signal by wafer bending can be automatically compensated in a differential capacitive measurement.

Robust z-axis acceleration sensor

A MEMS structure that provides an improved way to selectively control electromechanical properties of a MEMS device with an applied voltage. The MEMS structure includes a capacitor element that comprises at least one stator element, and at least one rotor element suspended for motion parallel to a first direction in relation to the stator element. The stator element and the rotor element form at least one capacitor element, the capacitance of which varies according to displacement of the rotor element from an initial position. The stator element and the rotor element are mutually oriented such that in at least one range of displacements of the rotor element from an initial position, the second derivative of the capacitance with respect to the displacement has negative values.

Growing community of inventors

Espoo, Finland

Hannu Vesterinen