Simulation, fabrication and characterization of a three-axis piezoresistive accelerometer

This paper presents a miniaturized three-axis piezoresistive accelerometer using bulk micromachining technology. The accelerometer consists of a highly symmetric single-crystalline silicon crossbeam structure with 12 conventional two-terminal p-type piezoresistors diffused on the surface of the beams. The die size of the acceleration chip is 3 mm × 3 mm. In addition, it is significantly smaller than those of previously presented approaches. It measures three components of acceleration up to ± 10 g on three orthogonal axes simultaneously. The average measured sensitivities of the fabricated sensor for accelerations A x , A y , A z on the X , Y , Z axes are about 1.14, 1.15, 0.98 mV (V g ) −1 respectively. The measurement results show a cross-axis sensitivity of <4%. This sensor is designed for use in biomechanical research applications such as human gesture recognition systems.