A Novel CNT-PDMS-Based Tactile Sensing Array With Resistivity Retaining and Recovering by Using Dielectrophoresis Effect

In this paper, we present a novel resistive sensing array capable of retaining and erasing tactile images. The sensing material was prepared by dispersing multiwalled carbon nanotubes (CNTs) and silver nanoparticles through polydimethylsiloxane (PDMS) polymer with the assistance of the dielectrophoresis (DEP) technique. When the sensing element is pressed, a number of conductive CNT networks within the polymer are broken, thereby increasing the resistivity of the element. The polymer retains resistivity following the removal of the external force, and resistivity can be recovered to the original value using DEP to reform the conductive CNT networks. This study demonstrates the performance and repeatability of the proposed sensing elements and investigates the characteristics of devices with various electrode gaps. We also designed and implemented corresponding scanning circuitry for sensing and recovering resistivity, and produced tactile images using an 8 × 8 array. The proposed sensing array shows considerable potential in pressure imagers, inertia switches, and other applications.