Versatile programmable somatosensory soft actuators based on highly conductive and robust MXene-integrated hydrogel

Abstract

In nature, various living organisms such as elephants can perceive and manipulate objects using their trunks. Inspired by biological structures, numerous hydrogel soft robots have been investigated; however, the weak mechanical properties and low conductivity of hydrogels limit their potential applications. Herein, the high-intensity, fast NIR-responsive hydrogel actuator based on bacterial cellulose (BC) as the passive layer and the high conductive hydrogel sensor with BC treated by thermionic source of butyl-3-methylimidazolium chloride (B-BC) as the passive layer are reported. The active layer consists of poly(N-isopropylacrylamide) (PNIPAm), functionalized silica nanoparticles (VSNPs), and 2-isocyanatoethyl methacrylate-modified MXene (M-MXene). Polymer is capable of grafting onto the VSNP surface to generate fast-transport channels for water expulsion, thereby significantly enhancing photoresponsive speed. Leveraging the pre-polymerization solution’s penetration into BC and the strong hydrogen bonding present, the interfacial toughness of the bilayer hydrogel (BC-GEL) reaches 33 N m⁻¹ with a tensile strength of 2.1 MPa. As a proof of concept, BC-GEL is programmed as multidimensional grippers and perceptual actuators for intelligent traffic monitoring. Additionally, B-BC, obtained through in situ molecularization with a thermionic source, exhibits a conductivity of up to 6.74 S m⁻¹. Owing to the excellent sensing properties, B-BC-GEL can be prepared as somatosensory actuators and multi-appliance sensors. This research offers innovative insights into hydrogel self-sensing actuators for intelligent traffic safety monitoring systems and demonstrates significant potential for applications in human health detection and medical wearable electronic devices.