Bacterial cellulose nanofiber-reinforced PVA conductive organohydrogel for flexible strain sensors with high sensitivity and durability

Flexible strain sensors based on conductive organohydrogels have aroused wide range of interests owing to their potential utilization in human health and motion detecting. However, the mechanical performance and sensitivity of the organohydrogel sensors need to be further optimized. Herein, we have designed a dual-network organohydrogel utilizing poly(vinyl alcohol) (PVA) as raw materials, bacterial cellulose (BC) nanofibers as reinforcements, tannic acid (TA) as crosslinkers and multiwall carbon nanotubes (CNTs) as conducting fillers. The constructed C-PVA/BC/CNT organohydrogel shows good mechanical properties and high sensitivity. The resistance of the C-PVA/BC/CNT organohydrogel can be remarkably changed during deformation, demonstrating superior synchronicity between mechanical stimulus and electric signals, and thus can be used as piezoresistive strain sensors. In addition, the C-PVA/BC/CNT organohydrogel also exhibits favorable durability under different strains, and excellent cycling stability during loading/unloading processes. This C-PVA/BC/CNT organohydrogel can be used to monitor human motion and physiological activities, and has great potential applications in wearable electronic devices.