High‐Performance, Superhydrophobic, and Wearable Strain Sensor for Amphibious Human Motion Detection

Abstract Wearable strain sensors with water repellency can enable the monitoring of human health and body motions when in contact with water; however, realization of such sensors with both high sensitivity and dynamic wetting behaviors simultaneously in air and underwater environment is a challenging task. Herein, a superhydrophobic, breathable, and wearable microfiber composite (SBWMC) strain sensor is fabricated using a stearic acid functionalized multi‐walled carbon nanotubes/TiO 2 modified textile. The resultant network of hierarchical micro/nano structure endows the SBWMC surface with excellent conductivity and water damage prevention, and it maintains superhydrophobicity after mechanical abrasion, illumination, and water soaking. More importantly, the SBWMC strain sensor simultaneously achieves the wide sensing ranges (strain over 100%) and superior sensitivity (gauge factor of 461.5) in air, and it can efficiently monitor real‐time bending of human joints in air. Compared to traditional sensors, this SBWMC strain sensor also exhibits superior sensitivity in underwater environment, even comparable to that in air. Undoubtedly, such smart sensor offers broad application prospects in next generation of wearable electronic devices in extremely humid environments.