Ultrasensitive Touch Sensor for Simultaneous Tactile and Slip Sensing

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 and data decoupling. Simultaneously conducting tactile and slip sensing presents significant challenges for the design, structure, and performance of sensors. In this work, a highly sensitive sandwich-structured sensor is achieved by exploiting the porosity and compressive modulus of the sensor's functional layer materials. 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. Due to this ultra-high sensitivity, coupled with spectral analysis, it allows for dual-mode detection of both tactile and slip sensations simultaneously. This novel fabrication strategy and signal analysis method provides a new direction for the development of tactile/slip sensors. An ultrasensitive piezoresistive touch sensor is developed using phase inversion along with the sacrificial template method and used for normal pressure and slip sensing. It can perform multimodal sensing on complex contact states. The output signal is processed using a wavelet transform to obtain the frequency-domain characteristics of the slip signal and achieve simultaneous detection of pressure and sliding states. image