Laser‐Induced Hierarchical Microcone Arrays for Flexible Tactile Sensors with High Sensitivity and Ultrabroad Detection Range

Abstract

Flexible tactile sensors have received widespread attention in many potential applications such as intelligence robots, the Internet of Things, and various wearable devices. However, most structure‐enhanced devices are in single‐patterns with limited improvement of sensitivity and working range. Herein, a double‐layered capacitive tactile sensor (DLCTS) with hierarchical microcone arrays, which consists of carbon nanotubes (CNTs) and polydimethylsiloxane (PDMS) is reported. Relying on its intrinsic hierarchical framework and optimized CNTs/PDMS ratios, the DLCTS exhibits an ultrabroad working range of 0–1400 kPa and a high sensitivity of 0.082 kPa−1. Moreover, this sensor shows favorable sensing performance with excellent durability (over 5500 cycles) and a fast response time (≈40 ms). Diverse powerful applications are demonstrated, including active monitoring of human elbow/knee flexion, respiratory state, walking mode, and convenient Morse code communication. It is envisioned that this sensor should be widely used in potential scenarios such as intelligent wearable devices and medical monitoring.