Bio-Inspired Artificial Receptor with Integrated Tactile Sensing and Pain Warning Perceptual Abilities

Abstract

Inspired by the mechanism of touch and pain in human skin, we integrated two ion-sensing films and a polydimethylsiloxane (PDMS) layer together to achieve a bionic artificial receptor with the capacity of distinguishing touch or pain perception through ion-electrical effect. The ion-sensing film provides the carrier of touch or pain perception, while the PDMS layer as a soft substrate is used to regulate the perception ability of receptor. Through a series of experiments, we investigated the effects of physical properties of the PDMS layer on the sensing ability of an artificial receptor. Further, contact area tests were performed in order to distinguish touch or pain under a sharp object. It is revealed that the pressure threshold triggering the touch and pain feedback of the artificial receptor presented an increasing trend when the elastic modulus and thickness of the PDMS substrate increase. The distinction ability of touch and pain becomes more pronounced under higher elastic modulus and larger thickness. Furthermore, the induced pain feedback becomes more intense with the decrease of the loading area under the same load, and the threshold of pain drops down from 176.68 kPa to 54.57 kPa with the decrease of the radius from 3 mm to 1 mm. This work potentially provides a new strategy for developing electronic skin with tactile sensing and pain warning. The pressure threshold and sensing range can be regulated by changing the physical properties of the middle layer, which would be advantageous to robotics and healthcare fields.