The Polymer Society of Korea

Abstract

The development of on-skin electronics requires materials that combine electrical conductivity, mechanical flexibility, and skin adhesion. Traditional conductive hydrogels often use additional fillers or additives like PEDOT:PSS, which can weaken the material structure and reduce long-term stability. In this work, we present a new type of additive-free, intrinsically conductive granular hydrogel based on the controlled assembly of conductive polymer microgels. By using granule structure, we achieve both high resolution printability and strong skin adhesion without external crosslinkers. The microgel-based network shows strong shear-thinning behavior and fast recovery, enabling precise on-skin deposition through 3D printing. The high surface area of the granular particles improves interfacial contact and energy dissipation, ensuring stable attachment for human-machine interfaces. This purely conductive platform represents an important step forward in next-generation soft bioelectronics.