Highly Sensitive Flexible Resistive Strain Sensor Based on Swelling-Coating Method for Wearable Electronics

Flexible resistive strain sensors are widely applied in activities such as human motion analysis and human-machine interaction. However, ensuring the stability of conductive networks while achieving good performance is a major challenge in designing and producing flexible resistive strain sensors. This article explores the advantages of swelling-coating method in improving the performance and stability of strain sensor. The conductive fillers of carbon black (CB) and carbon nanotubes (CNTs) were firmly fixed on the surface of electrospun polydimethylsiloxane (PDMS) flexible substrate using the swelling coating method, which can ensure the stability of the conductive network and improve the durability of the sensor. Due to the excellent mechanical performance of the electrospun PDMS film and the stable conductive bridge structure, the sensor has a high sensitivity (up to 467), a wide strain range (0%-120%), a rapid response time (120 ms), exceptional repeatability, and hysteresis. Moreover, the significant potential of the sensor was observed in applications such as human motion detection, wind force measurement, and human-machine interaction, which underlining the outstanding promise of the developed sensor.