MEMS Array Tactile Sensors with a Self-Calibration Structure

In this paper, we propose a self-calibration technique for MEMS array tactile sensors based on the demand for high precision and high performance of tactile sensors in robotics applications. The chip is fabricated using the piezoresistive principle with high sensitivity and low nonlinearity. The area of the sensitive part is no larger than 5mm x 5mm, and the chip includes 16 groups of silicon beams for measuring x-axis stress, 16 groups of silicon beams for measuring y-axis stress, and 32 groups of silicon beams for measuring z-axis stress. To solve the problem of device measurement accuracy and the complication of machine calibration operation, this proposed design of a tactile sensing array is self-calibrated by both single-electrode drive and double-electrode drive. The finite element simulation proves that the z-axis self-calibration range is 0-0.76N and the x/y-axis self-calibration range is 0-0.097N under 20V drive. Overall, the present work can be used in the field of robot hands with high precision requirements and provides a good prospect for the development of robot haptic applications.