Fragmented Graphene\nAerogel/Polydimethylsiloxane Sponges\nfor Wearable Piezoresistive Pressure Sensors

Abstract

High-performance flexible pressure\nsensors are critical to realizing\nelectronic skin and wearable devices. It is the persistent pursuit\nof researchers to develop more sensitive flexible pressure sensors.\nHere, we propose a simple and effective strategy to fabricate flexible\npiezoresistive pressure sensors based on fragmented graphene aerogel\n(FGA)/polydimethylsiloxane (PDMS) sponges. Using FGA as a conductive\nfiller and NaCl particles as a porogen and blending with PDMS, a composite\nmaterial FGA@PDMS with a sponge structure was obtained. Then, the\ncomposite FGA@PDMS was dip-coated with FGA to achieve the FGA/FGA@PDMS\nsponge. Finally, the interdigitated electrode was printed as the bottom\nelectrode by the screen-printing process to complete the preparation\nof the FGA/FGA@PDMS sensor. The results show that the fabricated flexible\npiezoresistive pressure sensor has higher sensitivity (0–10\nkPa, 2235.84 kPa^–1), good recovery, shorter response\ntime (∼120 ms), and stable response under 1000 cycles of loading\nand unloading. Moreover, we investigated the applicability of the\nFGA/FGA@PDMS sensor as a wearable device and its application in practical\nsensing. Human motion detection such as arm bending, fingers, and\nsoles of the feet shows that the sensor has good detection ability.\nThe light-emitting-diode series circuit and the bluetooth-based wireless\npressure sensor verification prototype system demonstrate the potential\nof the sensor for practical applications.