Sandpaper-assisted preparation of microstructured multifunctional PANI/PVA composite hydrogel film for high-sensitivity pressure sensors with accurate pressure identification and motion monitoring

Abstract

Bio-inspired microstructure surface flexible piezoresistive sensors offer an attractive opportunity for a variety of wearable device applications. Unfortunately, the realization of high-performance piezoresistive sensors still faces great challenges owing to the balance between responsitivity and sensing capability of them, as well as being limited by the level of deformation of their surface structures. Here, we propose a simple and efficient, low-cost sandpaper-assisted solution casting-scraping strategy to fabricate PANI/PVA hydrogel film with the reverse random height distribution (RHD) spinosum microstructure on the surface that is simultaneously conductive, flame retardant, and EMI shielding. The flexible piezoresistive sensor designed based on this film can detect pressure from 0.01 N to 20 N with a responsitivity of 77.7263 kPa−1 in the region of 0.03183–1.27324 kPa, a quick response/recovery delay of 18 ms/30 ms, and a good reliability within 2000 load-unload cycles. Notably, this piezoresistive sensor can accurately identify objects of different masses and monitor physiological signals of human motion, and can also produce significant current responses to extremely slight mouse clicks and handwriting styles. The successful preparation of multifunctional PANI/PVA microstructured film provides a new idea to explore the potential applications of piezoresistive sensors in flexible wearable electronic devices.