Vacuum‐Filling of Binary Metal for Soft Strain Sensor

Abstract Fibers have played an indispensable role in the development of human civilization. However, traditional fibers often fail to meet the demands of modern advancements. Smart fibers, especially conductive fibers, have received widespread attention in recent years. Liquid metal (LM) conductive fibers have emerged as a prominent area of research focus due to their unique combination of high conductivity and flexibility. However, researchers typically focus solely on the conductivity and fluidity, while the unique characteristics of LM have not been fully utilized in smart fibers. In this work, a Ga‐In binary metal is successfully injected into hollow polymer fibers using a vacuum filling technique, and prepared a leak‐free binary metal fiber (BMF) with multiple responsive properties. The influence of BM phase transition on BMF properties is investigated, and its application in human health and motion detection are explored.