A structure of angular acceleration sensor using silicon cantilevered beam with piezoresistors

A piezoresistive angular acceleration sensor is developed by micromachining. The proposed angular acceleration sensor consists of four identical silicon cantilevered beams with piezoresistors which are arranged at the circumference of the rotary machine. The value of the piezoresistor changes according to the acceleration. The fabrication method of the silicon cantilevered beams and the electrical characteristics of the piezoresistors are shown. The theoretical relation between the acceleration force and the resistance variation of the piezoresistor is derived in accordance with a geometrical model of the silicon cantilevered beam. The simple dynamical behavior of the piezoresistive cantilevered beam is also discussed. Then, the optimal arrangement of the uniaxial acceleration sensors for measuring the angular acceleration in the rotary machine is considered. Experimental results are shown and discussed