Ultrasensitive touch sensor for simultaneous tactile and slip sensing

Abstract

Abstract Touch is a general term to describe mechanical stimuli. It is extremely difficult to develop touch sensors that can detect different modes of contact forces due to their low sensitivity. A high sensitivity response to complex contact states, such as pressure and slip, requires effective material design strategies for the sensor sensitivity layers. In this work, an ultrasensitive piezoresistive touch sensor is developed using a one-step phase-inversion-to-film strategy along with the sacrificial template method. The spectral analysis of the output signal is performed using a wavelet transform. This enables the sensor to be used for normal pressure and slip sensing. This work confirms that an interconnected porous structure can be easily controlled using this strategy. The sensor shows an ultra-high sensitivity of 1167 kPa − 1 and a low-pressure detection limit of 1.34 Pa due to its considerably low compression modulus of 23.8 Pa. A wavelet transform is used to successfully detect different contact states and identify various materials. This novel fabrication strategy and signal analysis method provides a new direction for the development of tactile/slip sensors.