Cohesive thermoplastic-assisted patterning and assembly of a textile-supported piezoresistive sensor for monitoring human vital signs

Abstract

Flexible piezoresistive pressure sensors have attracted great attentions due to their critical roles in wearable electronics. It is highly desirable to develop a low-cost and facile method for fabricating textile-supported piezoresistive pressure sensors with designed patterns. Herein, we use a pre-cut thermoplastic as both mask and separator to deposit silver nanowires (AgNWs) and to seal two conductive textiles, respectively, for the construction of a textile-supported piezoresistive pressure sensor. The typical sheet resistance of the AgNWs-coated textile is as low as ∼50 Ω/square. After sealing at 100 °C, the sensor could display a significant resistance change in response to a certain pressure. The as-prepared devices possess high sensitivity, fast response and excellent durability (more than 500 cycles of pressure loading/unloading). Human motions (bending/unbending of arm and thumb) and vital signs (respiration rate/intensity and neck pulse) could be real-time monitored by those devices. By simply cutting the thermoplastic with a paper cutter, the sensors with various patterns could be obtained, demonstrating that the thermoplastic-assisted approach could combine both functionality and aesthetics in building textile-supported piezoresistive pressure sensors. This work may provide a simple and cost-effective strategy to produce textile-based piezoresistive pressure sensors for wearable electronic applications.