A CMOS Micromachined Capacitive Tactile Sensor With Integrated Readout Circuits and Compensation of Process Variations

作者：Tsai Tsung Heng^*; Tsai Hao Cheng; Wu Tien Keng

来源：IEEE Transactions on Biomedical Circuits and Systems, 2014, 8(5): 608-616.

DOI：10.1109/TBCAS.2014.2358563

• CMOS integrated circuits
• micromachining
• tactile sensors

This paper presents a capacitive tactile sensor fabricated in a standard CMOS process. Both of the sensor and readout circuits are integrated on a single chip by a TSMC 0.35 mu m CMOS MEMS technology. In order to improve the sensitivity, a T-shaped protrusion is proposed and implemented. This sensor comprises the metal layer and the dielectric layer without extra thin film deposition, and can be completed with few post-processing steps. By a nano-indenter, the measured spring constant of the T-shaped structure is 2.19 kNewton/m. Fully differential correlated double sampling capacitor-to-voltage converter (CDS-CVC) and reference capacitor correction are utilized to compensate process variations and improve the accuracy of the readout circuits. The measured displacement-to-voltage transductance is 7.15 mV/nm, and the sensitivity is 3.26 mV/mu Newton. The overall power dissipation is 132.8. mu W.

• 出版日期2014-10