Fast-response and durable liquid metal wire for wearable electronics

This work presents a strain sensor which is based on high ductility liquid metal coated on traditional commercial lastex yarns with a unique spiral wound structure. The prepared sensor exhibits exceptional flexibility, elasticity, softness of 0.23 N at 100% tensile strain. It is lightweight, weighing only 1 g/m, and boasts a low cost of less than 1 dollar. The sensor has the ability to detect both static and dynamic in-plane tension and normal pressure. It showcases remarkable sensing characteristics of good sensitivity (0.82 for tension, 12.6 N−1 for pressure), extraordinary linearity within 10–100% strain range with goodness-of-fit value over 0.997, rapid response of less than 10 ms, high resolution spanning up to 0.3%, and high durability over 100,000 repetitive cycles. A smart glove based on the proposed strain sensors achieves gesture recognitions using machine learning technique, with an accuracy of 100%. The outstanding performance of this sensor highlights its potential as an affordable and advanced candidate for wearable electronics, which can have wide-ranging applications in sports, healthcare, entertainment, education, and industry.