Ultra-Stretchable Porous Fiber-Shaped Strain Sensor with Exponential Response in Full Sensing Range and Excellent Anti-Interference Ability toward Buckling, Torsion, Temperature, and Humidity

As a crucial element for wearable devices, high-performance strain sensors have been spotlighted as an ideal strategy to develop machine-human interfaces and healthcare systems. It still remains a huge challenge to construct flexible strain sensors with equational response in a broad range. Herein, highly stretchable multi-walled carbon nanotubes (MWCNTs)-decorated thermoplastic polyurethane (TPU) fibers with a porous microstructure are produced through a scalable and facile strategy by wet-spinning and ultra-sonication. The fiber is composed of pure TPU fibers with MWCNTs decorated on the surface. The porous fiber is then assembled as a strain sensor. Interestingly, the effective MWCNTs distribution on the TPU fiber enables exponential sensing over the whole strain range. The sensor possesses a high gauge factor (GF, 102 at 300% strain), very large workable sensing range (300% strain), excellent durability (10 000 cycles), light weight (0.85 g cm(-3)), and fast response (200 ms). The as-prepared strain sensor exhibits excellent insensitive properties toward buckling, torsion, temperature, and humidity stimuli. Based on the high sensing performance, the fiber-shaped strain sensor detects human movements precisely by directly attaching to skin or embedding in garments, demonstrating huge potential in human-machine interfaces, health monitoring application, etc.