Polyborosiloxane-Encapsulated Carbon Nanotube/Polyurethane Foams for Multifunctional Pressure Memory and Pain Bionic Sensors

Abstract

Electronic skin (e-skin) is a bionic human skin material that is widely used in artificial intelligence devices. Pressure sensors, as the main component of e-skin, can perceive active pressure spatial distribution in real time. However, in addition to perceiving touch and pressure, human skin also has the ability to sense pain after being impacted or heavily pressed. Therefore, it is hoped that e-skin has the ability to sense the occurrence and disappearance of pain. Here, a pressure memory sensor (PM sensor) based on pressure memory foam (PM foam) was fabricated by a simple and easy-to-scale preparation process. PM foam exhibited excellent electrical conductivity due to the dense three-dimensional conductive network formed by carbon nanotubes (CNTs). PM sensors can achieve pressure memory and spontaneous recovery performance due to self-adhesion between the cell walls provided by polyborosiloxane (PBS). We investigated the effects of CNT and PBS contents on PM sensor sensitivity and memory time and realized the adjustment of sensitivity (0.012–0.099 kPa–1) and memory time (54–325 s). The sensor can bionically sense pain under heavy pressure or impact. In addition, PM foam exhibited excellent electromagnetic interference shielding performance and achieved a shielding effectiveness of more than 30 dB. PM foam realized the intelligent regulation of electromagnetic wave reflection and electromagnetic wave absorption through the conversion of a foam state and solid state. PM foam had excellent Joule heating performance to resist extreme cold environments. Multifunctional pressure memory and pain bionic sensors have great significance and application prospects in e-skin.