Core-shell porous LM/TPU fibers with tunable conductive properties for use as strain and pressure sensors

Abstract

Flexible wearable sensors have attracted widespread attention in health monitoring, human-machine interaction, and biomedical applications. However, developing a flexible sensor that possesses high sensitivity, wide detection range, and matches the conductive material with the modulus of elasticity remains challenging. Here, we developed a coaxial wet spinning process to fabricate conductive fibers with a core-multi-hollow-shell structure, termed LHPTF. The shell comprises a hollow porous structure of TPU, while the core consists of gallium-based LM with excellent electrical conductivity. LHPTF fibers exhibit electrical conductivity of 8690 S cm⁻¹, high flexibility, appropriate strength, and high elongation at break. The hollow porous structure of TPU fibers can be adjusted with various hollow diameters, thereby enabling the switching between stable conduction and strain sensing of conductive fibers. Due to the protection provided by TPU, LHPTF fibers exhibit good environmental durability and stability. We also demonstrate the application of these fibers in wearable sensors and stable conductor.