Constructing a continuous reduced graphene oxide network in porous plant fiber sponge for highly compressible and sensitive piezoresistive sensors

Flexible pressure sensors as wearable electronic devices to monitor human health have attracted significant attention. Herein, a simple and effective carbonization-free method is proposed to prepare a compressible and conductive reduced graphene oxide (rGO)–modified plant fiber sponge (defined as rGO-PFS). The introduced GO can not only coat on the surface of plant fibers, but also form a large amount of aerogel with microcellular structure in the macroporous PFS. After reduction treatment, the rGO-PFS can form a double-continuous conductive network of rGO aerogel. With the improvement of polydimethylsiloxane (PDMS), the rGO-PFS@PDMS composite exhibits outstanding compressibility (up to 60% compression strain), excellent durability (10,000 stable compression cycles at 50% strain), high sensitivity (234.07 kPa−1 in a pressure range of 20 ~ 387.2 Pa), low detection limit (20 Pa), and rapid response time (28 ms) for practical wearable applications. Graphical Abstract: A compressible and conductive reduced graphene oxide–modified plant fiber sponge is prepared by a simple and effective carbonization-free method. With the improvement of polydimethylsiloxane, the sponge exhibits outstanding compressibility, durability, high sensitivity, low detection limit, and rapid response time for practical wearable applications.