Mohammed Nabeel, AliJ. Addie, Béla Viskolcz, Mariann Kollar, Béla Fiser, Lászlo Vanyorek
Abstract
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 highperformance pressure sensors with significant implications for wearable technologies and soft robotics.
Keywords: E-skin, nanocomposites, N-doped CNT, piezoresistive sensors, polyurethane-silicone rubber nanocomposite, wearable electronics