PANI/rGO−PAM/PVA hydrogels with applications in supercapacitive, photoelectric and strain sensing

The high integration and multifunctionality in flexible electronic device play an important role in its development. In this study, we developed multifunctional hydrogels integrated with supercapacitive, photoelectric, and strain-sensing capabilities. The hydrogel composite consists of PAM/PVA matrix with polyaniline (PANI) and reduced graphene oxide (rGO) as conductive components. Two different acid dopants, citric acid (CA) and hydrochloric acid (HCl), were employed to investigate their impact on photoelectrochemical capabilities of hydrogels. Both CA-doped and HCl-doped hydrogels exhibited remarkable supercapacitive performance, achieving areal capacitances of 492 mF/cm2 and 538 mF/cm2, respectively. Furthermore, both hydrogels demonstrated photosensitivity towards shorter wavelengths such as ultraviolet (380 nm) and blue (475 nm) light. Lastly, the proposed hydrogels serving as highly sensitive strain sensors was verified through effectively sensing arm bending movements.