Recent advances in silk-based wearable sensors

In recent years, wearable electronics has received extensive attention, providing new opportunities for implementing health monitoring, human disease diagnosis and treatment, and intelligent robotics. Sensor is one of the key components of wearable electronics. Silk (Bombyx Mori) material shows unique features including high yield, excellent tensile strength (0.5–1.3 GPa) and toughness ((6–16) × 104 J/kg), good biocompatibility, programmable/controllable biodegradability, novel dielectric properties, and various material formats. With the rapid development of biomaterials and related manufacturing technologies, advanced silk-based materials have been studied and applied to wearable sensors. Here, we firstly introduce the five-level structure of silk fibroin from bottom to top and characteristics of silk-based advanced materials, and then review the research progress of silk-based advanced materials in wearable sensors in recent years, including mechanical sensors, electrophysiological sensors, temperature sensors and humidity sensors. The working mechanism, structure and performance of different sensors, the role of silk proteins in them, and their applications in health monitoring are discussed and summarized. Finally, the challenges and future prospects of silk-based wearable sensors in practical applications are put forward.