A multistimuli‐responsive recyclable poly(vinyl alcohol)/perylene imide hydrogel of high‐performance piezoresistive sensors for human wearable devices

Abstract

AbstractMultiple factors stimulate human beings in their daily lives, but uniformly collecting these signals is challenging. This study proposes a physically cross‐linked method that employs hydrogen bonding interactions to prepare poly(vinyl alcohol)/perylene imide (PVA/PI) hydrogels. The prepared PVA/PI hydrogels demonstrate favorable compressive strength (45–75 kPa) and adhesion properties. At room temperature, elongation reaches approximately 400%. Additionally, the PVA/PI hydrogels exhibit strong mechanical properties, with a maximum elongation of 200%, and high ionic‐electronic conductivity of 29.6 S m−1, even after being soaked in a 2 M HCl solution for 24 h. The water‐soluble PI in the PVA/PI hydrogels is environmentally responsive, resulting in a current response time of 100 ms under 365 nm irradiation, as well as reversible fluorescence changes across different pH levels. Both the PVA5/PI1 and PVA5/PI1/HCl2 (the concentrations were 5 wt%, 1 mg mL−1 and 2 mol L−1, respectively) hydrogels demonstrate high sensitivity (0.49 and 7.88 kPa−1) and a wide pressure monitoring range (0.088–30.67 kPa and 0.088–18.67 kPa, respectively) as pressure sensors. The first developed recyclable PVA/PI hydrogel shows promise for use in wearable sensing devices and is expected to be applied in complex environments.