Integrating polyurethane-silicone rubber-nanohybrid systems for improved wearable pressure sensing

Flexible pressure sensors (FPS) are crucial for emerging applications like wearable electronics, human activity monitoring, and soft robotics. This study reports a scalable and cost-effective approach to fabricate high-performance piezoresistive FPS based on polyurethane-silicone rubber (PU-SR) nanocomposites. The synergistic integration of nitrogen-doped bamboo-shaped carbon nanotubes (N-BCNT) and carbon black (CB) nanofillers within the PU-SR matrix was achieved via a novel dip-coating and impregnation method. This technique enabled uniform nanofiller dispersion, enhancing electrical conductivity and mechanical stability. Comprehensive characterization using x-ray photoelectron spectroscopy (XPS), zeta potential, high-resolution transmission electron microscopy (HRTEM), and micro-computed tomography (Micro-CT) elucidated the structural features and morphological aspects. The optimized N-BCNT:CB/PU-SR nanocomposite exhibited exceptional piezoresistive performance, with a sensitivity of 0.4 kPa-1 in the 0-120 kPa range and 0.07 kPa-1 in the 180-1000 kPa range, along with remarkable durability over cyclic loading. When deployed as an electronic skin (e-skin), the sensor accurately detected various human motions, including finger, wrist, elbow, and knee movements, as well as twisting and stretching actions. This work shows a promising route towards fabricating cost-effective, flexible, and high-performance pressure sensors with significant implications for wearable technologies and soft robotics.Highlights Hybrid Nanocomposite sensors achieve high sensitivity over a broad pressure range. N-CNTs and CB enhance piezoresistivity and durability in PU-SR nanocomposites. Flexible sensors detect multi-joint human motions accurately. Alternative dip-coating technique ensures uniform nanofiller distribution. Cost-efficient sensors design suitable for wearable e-skin applications. Performance of flexible pressure sensors based on PU-SR nanocomposites reinforced with N-BCNT and CB exhibiting high sensitivity and robustness in real-time applications. image