Recyclable High-Performance Sensors Using Graphite-Doped PEDOT:PSS for Pulse Diagnosis in Traditional Chinese Medicine

In this paper, a graphite-reinforced structure (GNSRS) crack strain sensor with recyclability, high sensitivity, wide strain range, and single/dual sensing layer tunability was developed by utilizing the reinforcing effect of graphite nanosheets (GNSs) on PEDOT:PSS films and the recyclable property of acrylic acid films. The sensor significantly enhanced the sensitivity (GFmax = 166 325) through the modifying effect of GNSs on PEDOT:PSS and pre-positioned stress concentration sites. Meanwhile, a GNS sensing layer was formed underneath the PEDOT:PSS-GNSs composite sensing layer by modulating the GNSs’ concentration to form a double sensing layer structure, which realizes the controllable conversion of the single/double sensing layer structure and extends the sensing range to more than 80%. In addition, the sensor has excellent response characteristics and cyclic stability (>8000 cycles). Based on its tunable characteristics, we have successfully developed various application prototypes, such as pulse diagnosis in traditional Chinese medicine, speech recognition, dynamometers, and strain gauges, which fully demonstrate its potential for applications in physiological signal monitoring, speech recognition, and motion detection.