A PIEZORESISTIVE ACCELEROMETER

摘要

Disclosed is a force-balanced piezoresistive 3-axis accelerometer. An exemplary accelerometer (100) comprises a proof mass (104) which is coupled to a plurality of meanders (103), which further couple to a plurality of anchor pads (102) that extends out from each meander (103). The proof mass (104), meanders (103) and anchor pads (102) are integrally fabricated multilayer construct which comprises a base silicon layer (201), insulator 1 (202), insulator 2 (204), metal 1 (203) and metal 2 (205) arranged in an intermittent fashion and fabricated through CMOS compatible fabrication process. Piezoresistive sensing means is used in detecting acceleration in three degree of freedoms or directions in which piezoresistors (206) embedded within the multilayer construct are used to sense the movement of proof mass (104) and meanders (103) upon external force which exerted on the proof mass (104). Electrical signals upon the sensing are then generated and processed by electrical circuitry to provide DC biasing on respective anchor pads (102) to produce x-, y- and z-direction acceleration data in terms of magnitude and direction. The accelerometer is also designed with self- test capability in which the meanders (103) perform self-test by bending at least one meander while keeping other meanders stationary and measuring z-displacement. The resulting accelerometer has the potential for low power consumption due to DC biasing, low cost and high-accuracy operation over wide temperature range due to additional Wheatstone bridge circuit embedded within the multilayer construct.