High-Performance Flexible Capacitive Pressure Sensor based on Multi-Walled CNT for Motion Detection

High-performance flexible sensors characterized by high sensitivity, low detection limits, a wide working pressure range, and rapid response times have gained significant attention recently due to their essential role in advancing wearable smart devices, human-machine interaction, and healthcare systems. In this work, we present the fabrication of highly flexible and sensitive capacitive pressure sensors using Multi-Walled Carbon Nanotube (MWCNT)/Ecoflex composite electrodes. The sensors were fabricated using a straightforward dipping-drying method, facilitating the uniform adhesion of CNTs to the elastomer matrix. The resulting pressure sensors demonstrate exceptional performance, exhibiting high sensitivity (2.2% kPa⁻¹), fast response time (< 40 ms), and an extensive working range (0.03-30 kPa), with strong linearity (r² = 0.983). Several applications of human machine interaction are successfully demonstrated by using the developed sensors. This work presents a cost-effective and simple way to fabricate flexible pressure sensors for use as wearable devices across a range of applications, including motion monitoring, hand gesture detection, and human-machine interfaces (HMIs).