Prepressed Liquid Metal Fabric with Strain-Insensitive Conductance for Wearable Bioelectronics

The development of flexible conductors with high electrical conductivity, flexibility, and electromechanical stability is important for reliable signal transmission in wearable electronics. Here, we report a patternable liquid metal (LM) fabric with strain-insensitive performance, fabricated using a highly elastic knitted fabric (KF) as the substrate and a gallium-based liquid metal as the conductive coating. A patterned poly(3,4-ethylenedioxythiophene)(styrene sulfonate) (PEDOT:PSS) intermediate layer was introduced to enhance the interfacial adhesion and facilitate the selective deposition of LM on the textile substrate. In addition, pre‑oxidation of the LM followed by a prepressing treatment further promotes the permeation of liquid metal into the knitted fabric, thereby improving the stability of electrical conductivity. Benefiting from the pore structure of the fabric and the strong interfacial combination of liquid metal and PEDOT:PSS, this composite fabric achieves a strain capacity of 200% with low resistance variations, and the resistance change rates are 18.6% for longitudinal stretching, 20.4% for 45° diagonal stretching, and 24.8% for transverse stretching. When stretched by 100% along three distinct directions (transverse, longitudinal, and 45°), the resistance change rate remains below 5% in all cases, demonstrating excellent multidirectional strain-insensitive conductivity. Moreover, after 1000 cyclic stretching cycles under a 30% strain, the resistance fluctuation still stays within 3%. The resulting fabric exhibited excellent conductivity stability when applied to conductors, Joule heating, electrocardiogram (ECG), and near field communication (NFC), demonstrating its potential for next‑generation wearable electronics.