Biomimetic photonic crystal double-network hydrogel for visual and electrical dual signal bluetooth-enabled wearable sensor

Abstract

Inspired by organic skins in nature, photonic crystal (PC) wearable sensors are attractive for flexible motion-monitoring sensors. However, their poor mechanical property, fatigue resistance, and single-signal sensing limit their applications. Herein, a biomimetic PC wearable sensor with visual and electrical dual signal outputs is successfully developed by combining double-network hydrogels (DNHs) and polystyrene (PS) colloidal arrays. The sensor exhibits a remarkable tensile strength of 1.03 MPa, high strain of 1034.0%, and a low dissipated energy ratio of 9.52% due to multi-hydrogen bond interaction in DNHs, enabling anti-fatigue performance and long-term use. More importantly, the sensor achieves durability and reversibility in both visual and electrical dual signal outputs while demonstrating competitive mechanochromic sensitivity of 3.67 nm%⁻¹ and gauge factor of 0.71. Notably, the PC wearable sensor is integrated with a Bluetooth module to construct an interactive wearable device for real-time visual and electrical feedback generated by the movements of different parts of the human body, making it accurate and convenient to monitor human motion via smartphone. The integrated PC wearable sensor enables precise dual-sensing monitoring by facilely coordinating visual and electrical signals, demonstrating great potential in the applications of wearable devices, health monitoring, human–computer interfaces and so on.