Tailoring of photocurable ionogel toward high resilience and low hysteresis 3D printed versatile porous flexible sensor

Abstract

Flexible wearable sensors with high stretchability and portability are widely used in health diagnosis, sports monitoring, rehabilitation, and so on. Nevertheless, hysteresis, which is a problematic issue, prevails in flexible sensors due to the intrinsic viscoelasticity of soft materials. In this work, a photocurable resin containing ionic liquids (ILs) and hydrogen bond-rich acrylate monomer is prepared. Combined with an optimized lattice structure, the porous ionogel flexible sensors (PIFS) exhibit a higher pressure sensitivity and lower hysteresis (2.4%), which offers reliable signals during long-term loading (500 cycles). Further test results demonstrate prepared photocurable resin a promising material for digital light processing (DLP) 3D printer to print tailored PIFS with high stretchability and low Young’s modulus. Besides, the PIFS possesses antibacterial properties and accurate temperature variation detection. A lower glass transition temperature (-45.8 °C) of PIFS enables it to work in a cryogenic atmosphere. A series of custom-structured PIFSs is printed as wearable sensors for monitoring pulse, finger, gait, and other human motion. This facile preparation strategy is applicable for the printing of high-performance customized PIFS with a high throughput.