Highly Sensitive Tactile Sensing Array Realized Using a Novel Fabrication Process With Membrane Filters

Abstract

This paper presents a highly sensitive tactile sensing array. Sensing elements of the array comprise multiwall carbon nanotubes and polydimethylsiloxane polymer. A novel lithography process is proposed for fabricating an SU-8 mold for shaping the sensing cells in the array. In addition, a nylon membrane filter is proposed to serve as a mold for numerous microdome patterns, which were transferred onto a conductive polymer film. The proposed device features advantages, such as ultra-high sensitivity, flexibility, and a simple fabrication process. Tunneling piezoresistive effects of interlocked microdome structures fabricated using membrane filters with different pore sizes were observed. The measured maximum sensitivity and typical response time were approximately -7.73 kPa <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup> and 4 ms, respectively. In addition, the measured results show that the patterned polymer composite arranged in a row-column array can effectively eliminate the crosstalk effect. Moreover, measurements for various tactile sensing applications were demonstrated.