Preparation and Properties of Cellulose Nanofiber-Reinforced Ionic Conductive Hydrogels Sensor

Ionic conductive hydrogels have been applied in sensors, energy storage and soft electronics recently. However, most of the polyvinyl alcohol (PVA) based ionic hydrogels are mainly fabricated by soaking the hydrogels in high concentration electrolyte solution which can induce the waste of electrolyte. Herein, we have designed cellulose nanofiber (CNF) and polyvinyl alcohol (PVA) as raw materials. PVA-CNF organic hydrogels were prepared in a dimethyl sulfoxide (DMSO)/water binary solvent by one-pot method. PVA-CNF hydrogels were prepared with different contents of CNF and Al³⁺ ions to enhance the performance of ionic conductive hydrogels. Moreover, the resulting ionically-conductive hydrogels with 0.1% CNF exhibited stress up to 0.79 MPa (343.2% strain) and high ionic conductivity. The hydrogel sensor displayed a high linear gauge factor of 4.25 (0–200% strain), excellent stability, and reliability. The hydrogel sensor also showed excellent sensor performance for human motion monitoring. This work provides a new prospect for the design of cellulose reinforced conductive hydrogels via a facile method.