Large-Scale Nanofiber Manufacturing| Permeable and Durable Liquid-Metal Fiber Mat as lmplantablePhysiological Electrodes with Long-Term Biocompatibility

Professor Wei Yan from Tsinghua University and Researcher Ma Zhijun from Zhejiang Lab: Implantable Bioelectrodes with Long-Term Biocompatibility

Challenge: Implantable physiological electrodes provide unprecedented opportunities for real-time and uninterrupted monitoring of biosignals. Most implantable electronic devices use low-permeability thin film substrates that severely hinder tissue metabolism and compromise long-term biocompatibility.

Approach: Professor Wei Yan from Tsinghua University and Researcher Ma Zhijun from Zhejiang Lab proposed an interface regulation strategy. They immersed electrospun styrene-butadiene-styrene (SBS) nonwoven membrane substrates in a silver trifluoroacetate ethanol solution to fully adsorb silver ions onto the fiber matrix, then reduced the silver ions to silver nanoparticles (AgNPs), solving the problem of liquid metals (LMs) being difficult to fully infiltrate porous polymer substrates.

Innovation 1: The LM-Ag-pSBS electrode exhibited excellent conductivity, stretchability, and breathable/liquid-permeable properties. The enhanced adhesion between LM and SBS fiber nonwoven substrate inhibited LM shedding and improved electrode durability in dynamic physiological environments.

Innovation 2: Research demonstrated that using the electrode as an implantable neural interface for in vivo acquisition of electrocardiogram and electrocorticogram signals achieved long-term biocompatibility and high signal-to-noise ratio.