Wrinkled PPy Film/PVA Nanowires Spacer For Ultrahigh-performance Piezoresistive Sensor

Pressure sensor with high sensitivity is desirable for it's vast application values in fields like health care,wearable electronics and transportation.Here,we report a simple but rarely investigated approach to fabricate amazing high sensitivity piezoresistive sensors by using Polyvinyl Alcohol(PVA)nanowires(PVANW)as spacer between wrinkled and porous polypyrrole(PPy)film and PET/ITO sheet.The main features of the sensor are as follows:(1)Simple structure and novel mechanism: The sensor is simplely fabricated with PPy film,PVA nanowire and PET/ITO sheet.On one hand,PVA nanowires serve as contact spacer between PPy film and PET/ITO sheet,where the conductive path between PPy film and PET/ITO sheet can be altered with PVANW;on the other hand,the PPy film with intrinsic wrinkled and fluffy structure,shows various electrical conductivities under various external pressures.The above two traits contribute to high sensitivity.(2)Excellent performance: The PPy-PVA nanowire-PET/ITO sensor features with superior performances of ultrahigh sensitivity(109.9 k Pa-1,0–0.17 k Pa;228.5 k Pa-1,0.5–2 k Pa;11.9 k Pa-1,5–9 k Pa),low detection limit(2.97 Pa)and good stability(10,000loading-unloading cycles),which distinguish itself among numerous piezoresistive sensors.(3)Vast application values: PPy film and PVA nanowires can be obtained just by electrochemically synthesis and electrospinning,respectively.The simple fabrication process together with the excellent performance of the sensor manifest it a broad application prospect,and the fabrication procedure also provides a simple method to improve the performance of other piezoresistive sensors.