A self-healing and conductive ionic hydrogel based on polysaccharides for flexible sensors

Abstract

An ionic hydrogel based on polysaccharides with self-healing and conductive properties serves as the flexible sensors to record the information of pressing Morse codes and browsing web pages with a mobile phone. In this study, we proposed a self-healing conductive hydrogel based on polysaccharides and Li + to serve as flexible sensors. At first, the oxidized sodium alginate (OSA) was obtained through the oxidation reaction of sodium alginate (SA). Then OSA, carboxymethyl chitosan (CMC), and agarose (AGO) were dissolved in LiCl solution, respectively. Finally, the hydrogel was obtained through heating, mixing, and cooling processes. Because of the Schiff base structure and hydrogen bonding, the hydrogel demonstrates good mechanical and self-healing properties. The presence of Li + provides good conductivity for the hydrogel. In addition, we demonstrated the application of the hydrogel as the flexible sensors. It can perceive the process of pressing Morse code with the index finger as a pressure sensor and monitor sliding movement of the thumb as the strain sensor to browse the web with the mobile phone. Thus, the self-healing conductive hydrogel may have potential applications in flexible wearable sensors.