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

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 similar to 50 Omega/square. After sealing at 100 degrees 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.