In Situ Formation of Ion-Clusters on Liquid Metals Surface for Simultaneously Improving Adhesive Toughness and Conductivity Toward Epidermal Electrodes

Xinyu Chen,Yubing Fu, Xueling Yan, Siyu Gan, Wenwei Yang, Song Chen*, Lan Liu*

Abstract

Developing epidermal electrodes that possess mechanic softness, tough adhesion, and high conductivity simultaneously is important but still remains challenging. Here, polyvinylpyrrolidone (PVP) is introduced into poly(α-thioctic acid) (PTA) to in situ generate ion-clusters both in PTA network and on liquid metal particles (LMPs) surface, enhancing the mechanical strength and toughness of PTA, as well as its interfacial interaction with LMPs. As a result, a poly(TA-PVP)-LMPs (noted as PTPL) epidermal electrode is reported with mechanic softness (Young's modulus of 175.86 kPa), tough adhesion (1604 J m⁻²), high stretchability (>20 000%), rapid self-healing, and good biocompatibility. And attributed to the peel sintering of LMPs, the PTPL epidermal electrodes further exhibit high electrical conductivity (26.19 mΩ sq⁻¹) and low skin impedance, providing high signal-to-noise ratios (SNR of 28.07 dB) and accuracy in monitoring multiple human electrophysiological signals. This work provides a new strategy for balancing the tough self-adhesion, softness, and high conductivity of polymer materials in epidermal electrodes fabrication.

文章链接：

https://doi.org/10.1002/adfm.202501130