Carbon Black-Coated Fabric Blend as Piezoresistive Flexible Pressure Sensor for Motion Monitoring Applications

Flexible pressure sensors (FPSs) have garnered significant interest among researchers focusing on wearable electronics for motion recognition, health care, rehabilitation therapy, athletic performance monitoring, and more applications. Recently, fabrics known for their flexibility and comfort have become popular substrates for fabricating various flexible sensors. Of these flexible sensors, piezoresistive devices are favored for their simplicity and notable sensitivity to physical movements. This study presents a fabric composite created by coating a viscose staple fiber/linen blend with functionalized conductive carbon black (CB) using a simple drop-coating method and evaluates its pressure-sensing performance. The FPS with optimum CB content exhibited sensitivities of 41.1 kPa ${}^{\mathbf {-1}}$ and 1.4 kPa ${}^{\mathbf {-1}}$ in the pressure ranges of 0-1 kPa and 1-20 kPa, respectively. With a low detection limit of 10 Pa, a response time of 16 ms, a relaxation time of 63 ms, durability exceeding 5,400 cycles, and stable performance in various ambient conditions, the FPS has exhibited potential for applications in bending motion monitoring and information transmission.