Fully Physically Crosslinked Conductive Hydrogel with Ultrastretchability, Transparency, and Self-Healing Properties for Strain Sensors
Feng Ji, Pengbo Shang, Yingkai Lai, Jinmei Wang, Guangcai Zhang, Dengchao Lin, Jing Xu, Daniu Cai, Zhihui Qin
Abstract
Currently, conductive hydrogels have received great attention as flexible strain sensors. However, the preparation of such sensors with integrated stretchability, transparency, and self-healing properties into one gel through a simple method still remains a huge challenge. Here, a fully physically crosslinked double network hydrogel was developed based on poly(hydroxyethyl acrylamide) (PHEAA) and κ-carrageenan (Car). The driving forces for physical gelation were hydrogen bonds, ion bonding, and electrostatic interactions. The resultant PHEAA-Car hydrogel displayed stretchability (1145%) and optical transparency (92%). Meanwhile, the PHEAA-Car hydrogel exhibited a self-healing property at 25 °C. Additionally, the PHEAA-Car hydrogel-based strain sensor could monitor different joint movements. Based on the above functions, the PHEAA-Car hydrogel can be applied in flexible strain sensors.