Bioinspired Chicken-Foot-Structured Capacitive Tactile Sensor Based on an SR/MWCNTs Composite for Human Motion Monitoring, Morse Code Communication, and Robotic Grasping

Abstract

In advanced robotics and human−machine interaction interfaces, there is a strong demand for flexible sensors that combine highly sensitive tactile detection with structural flexibility. In this study, a capacitive flexible tactile device inspired by a bioinspired chicken-foot structure was designed using a silicone rubber (SR)/multiwalled carbon nanotubes (MWCNTs) composite. Through structural optimization, the sensor achieved localized stress concentration, thereby significantly enhancing pressure− response sensitivity, while the MWCNT network established stable conductive pathways within the SR matrix, allowing the device to maintain excellent performance under complex deformation. The sensor was fabricated using precision 3D printing combined with a layer-by-layer assembly process, ensuring high structural accuracy and good reproducibility. Performance tests showed that the device exhibited a maximum sensitivity of approximately 0.42 kPa−1 in the low-pressure region, low hysteresis of about 4%, a pressure resolution of approximately 0.094 kPa, and a minimum pressure detection limit of approximately 0.094 kPa over a nominal pressure range of 0–93.75 kPa; its response and recovery times were only 25–37.5 ms, and stable output was maintained over 1000 loading cycles. Application experiments further verified its functionality in human motion monitoring, gait analysis, finger pressing, and robotic grasping action recognition, demonstrating its multifunctional potential in wearable healthcare, human−machine interaction, and intelligent robotics. This study proposes a compact, high-performance, and scalable design strategy for flexible tactile devices, providing a reference for the development of next-generation intelligent tactile interfaces and wearable systems.