Preparation and application of fabric-based interlocking microstructured flexible piezoresistive sensors

Flexible piezoresistive sensors are the key components for monitoring human physiological signals. In this paper, multi-walled carbon nanotubes/poly- urethane (MWNTs/PU) conductive films with micro-pillar structure on the surface are prepared by a mixed solution template method, and the conductive films are integrated with fabric electrodes to investigate the effect of structural parameters on the sensing performance. The experimental results show that when the concentration of carbon nanotubes is 10%, it has good sensing properties, excellent mechanical properties and electrical conductivity. Compared to flat structure interlocking, micro-pillar structure flexible piezoresistive sensors exhibit high sensitivity (66.89 kPa−1), low hysteresis, fast response/recovery time (69 ms/53 ms), high stability (>8000 cycles), and a wide pressure response range (0–47.77 kPa). In real-time, the device monitors human physiological signals such as finger presses, knee bends, and wrist pulses. The high performance and ease of manufacture of this fabric-based hybrid porous microstructure sensor offer a new approach to designing and manufacturing future pressure sensors.