Six-beam piezoresistive accelerometer with self-cancelling cross-axis sensitivity

A novel six-beam piezoresistive accelerometer with self-cancelling cross-axis sensitivity was constructed using a unique porous silicon micromachining technique. The comparatively low sensitivity of a six-beam structure, due to the additional beams, can be simply overcome using a summing circuit. Moreover, the cross-axis sensitivity can be significantly reduced. A sensor with a summing circuit can exhibit a sensitivity of 0.68 mV/g with a nonlinearity of <2.0% up to 8 g, a cross-axis sensitivity of <1.0%, and a first resonant frequency of ~4.24 kHz