A fast self-healing multifunctional polyvinyl alcohol nano-organic composite hydrogel as a building block for highly sensitive strain/pressure sensors

Abstract

A conductive and biocompatible hybrid hydrogel was successfully assembled into an adhesive, flexible wearable sensor for ultra-sensitive human–computer interaction and smart detection, which holds excellent self-healing capability. This conductive, repairable and biocompatible hybrid network hydrogel is formed by dynamic supramolecular cross-linking of an MXene, PEDOT:PSS, polyvinyl alcohol and polydopamine. It uses conductively a functionalized MXene (titanium carbide) and PEDOT:PSS as the conductive network. The PVA–MXene–PEDOT:PSS–PDA organic hydrogel has an excellent ability to repair itself (within 1.8 s) and can be assembled into repairable, sticky, and soft intelligent sensors, which can accurately detect various human movements (including bending of fingers and wrists, gesture recognition, winking and expression changes). In addition, it can be assembled into a smart sensor for speed recognition and handwriting recognition. Due to the addition of PVA, the conductive hydrogel has good biocompatibility. Therefore, it can be installed on prostheses to realize the touch screen function and solve the problem of difficulty in controlling the screen using silicone prostheses, indicating that it has a huge application prospect in the field of bionic intelligent robots. Thus, stretchable and flexible hydrogel electronic sensors have great potential for human motion detection and smart detection due to their excellent self-healing capability, adhesive properties and wearability.