Mass-Produced Flexible Strain Sensors Based on Dip-Coating and Water Bath for Human–Computer Interaction

Abstract

Flexible strain sensors play a key role in the field of human–machine interaction because of their ability to sense deformation. To meet the needs of mass production of wearable electronic devices, it is very necessary to develop a strain sensor with excellent sensing performance and low-cost mass fabrication. In this article, a fabrication process of a flexible resistive strain sensor, which is perfectly matched by the combined method with dip-coating and water bath, is proposed. A layer of conductive polymers containing carbon black/multiwall carbon nanotubes/thermoplastic polyurethane (CB/MWCNTs/TPU) was quickly and evenly wrapped on the surface of the core-spun elastic yarn. Combining the synergistic conductive effect of the filler and the high elasticity of the yarn matrix, the designed flexible strain sensor has high sensitivity (gauge factor (GF) to 68), low detection limit, wide strain range, fast response time, fast recovery time, and high stability. The designed strain sensor exhibits outstanding sensing performance and wearability, which can be used for real-time monitoring of human joint bending and breathing state. Furthermore, a wireless operating system based on wearable data gloves has been developed to realize the remote synchronous movement of the human hand/the bionic manipulator. The results indicate that the proposed strain sensor has great potential in human–machine interaction and its fabrication technology provides guidance for the sensor in mass production.