Mussel-inspired wet-spun conductive fibers for stretchable electronics

Flexible conductive fibers have gained significant attention for their exciting potential in stretchable electronics, attributed to their thread-like structure, lightweight, and flexibility. However, it is still challenging to prepare adjustable conductive fibers that boast outstanding electronic characteristics using an eco-friendly and simple method. Inspired by mussel byssus threads, a new strategy for the preparation of conductive fiber was proposed by combining the wet-spun polyurethane (PU) fiber and liquid metal (LM) using tannic acid (TA) as a binder. The inherent adhesive property of TA with rich catechol/gallocatechol groups enables it as a binder to enhance the affinity of PU fiber to LM. The fiber (LM@TA-PU fiber, LTP) composed of TA-modified PU as a core and an EGaIn conductive layer exhibited a high electrical conductivity (3.522 × 10⁵ S m⁻¹) and a large tensile range (0–640 %). The fiber displayed a fast response time (63 ms), notable durability (over 5000 cycles), and very tiny detection of strain (0.1 %). Moreover, the LTP fibers were employed as flexible sensors and electrodes for the acquisition of signals. Based on the LTP fiber, wireless Bluetooth, and programming technology, intelligent applications displayed in a cell phone were implemented for gesture recognition and music playback control. This work offers a novel method to prepare flexible conductive fibers, opening up new possibilities for applications in motion monitoring, gesture recognition, and the Internet of Things.