Polydopamine-Based Multifunctional Hydrogel for Flexible Supercapacitor and Pressure Sensor Applications
Qing Xin, Danni Hu, Lingxiao Zhou, Guoqing Yang, Shangqing Liang, Jun Lin
Abstract
Flexible energy storage devices and sensors are two key factors for wearable electronics. Designing a multifunctional component that combines a sensor and high-performing energy storage is exciting but remains a great challenge. Here, a multifunctional hydrogel with mechanical properties has been prepared by introducing polydopamine (PDA) into a chemically crosslinked network of poly(vinyl alcohol) (PVA) and poly(ethylene glycol) (PEG). A film electrode containing PDA is grown in situ on the hydrogel, and the resultant device can be employed as a supercapacitor and pressure sensor simultaneously. The supercapacitor exhibits an areal specific capacitance of 210.2 mF cm –2 at a current density of 0.2 mA cm –2 . As a flexible sensor, the device has a broad pressure range and good sensitivity (0.57 kPa –1 ) with a pressure range of 0–5 kPa. The device can stably detect human motion from a gentle wrist pulse to tight clutching, providing a solution for integrating energy storage devices with functional sensors in wearable electronic applications.