Flexible and Wearable Piezoresistive Sensors Based on Double Wrinkled Layers for Motion Monitoring and Human Physiological Signal Monitoring

Abstract

In recent years, wearable devices have received increasing attention due to their potential applications in human motion detection and physiological signal monitoring. It is meaningful to develop sensors with excellent performance and good wearability. In this study, researchers designed a face to face double wrinkled layer piezoresistive sensor. Using the prestretching and releasing method, two preprepared conductive films were prepared into wrinkled layers and finally encapsulated with 3 M tape and PDMS resin to obtain a piezoresistive sensor based on double wrinkled layers. Furthermore, the influence of the thickness of the conductive film and prestretching amplitude on the performance of the sensor were studied. The sensor exhibits high sensitivity (2.02 in the strain range of 0–10%; 0.88 in the strain range of 10–20%), a wide detection range (1.3 × 102 kPa), fast response (120 ms), good cycle stability (400 cycles), and excellent temperature stability (within −20 to 80 °C). In addition, it exhibits good performance in human motion monitoring, pulse monitoring, and voice monitoring. In the future, sensors have broad application prospects in the field of wearable devices and provide a solution for the design of piezoresistive sensors.

Strain-Sensor-In-Pixel Technology for Resolution-Sustainable Stretchable Displays

“…This approach addresses the issue faced by continuous thin films, which tend to crack under strain, leading to discontinuities and a significant reduction in conductivity. − Among the nanomaterials, Ag-based nanocomposites are considered one of the best candidates for strain sensors and interconnects owing to their high electrical conductivity, chemical stability, and cost-effectiveness. − In this research, for the context of developing sophisticated stretchable displays, Ag thin film has been selected as a fundamental layer, utilizing the sputtering processa commonly employed process in commercial display manufacturingfor its superior integration capability and reliability. However, as mentioned above, sputtered Ag thin films on stretchable elastomer substrates are fragile, even at low external tensile strain, leading to entire rupture or cracking due to their intrinsically poor ductility under tensile strain. − Hence, constructing a wrinkled structure by performing the Ag sputtering deposition onto a 10% prestretched polydimethylsiloxane (PDMS) substrate using a shadow mask was attempted as shown in Figure a. This helps dissipate the strain stress and reduces the occurrence of abrupt thin film fractures.…”