The Polymer Society of Korea

Abstract

In this study, we present a direct ink printable stretchable conductive hydrogel designed for high-aspect-ratio bioelectronics. The ink is composed of monomer, gelation agent, protein, and conductive polymer, with ionic liquid and nano clay added to enhance electrical conductivity and mechanical compliance. Laponite is incorporated as a rheological modifier, enabling the ink to maintain shape fidelity prior to UV-induced crosslinking. The printed hydrogel structures demonstrate an aspect ratio of 10:1, stretchability up to 420%, and stable conductivity of 7.44 S/m under hydrated conditions. This enabled vertical stacking with fine resolution, essential for compact and multilayered bioelectronic systems. The succeeded in printing microneedle and mechanical softness suggest strong potential for integration with biological tissue. This work highlights a promising route toward the fabrication of conformal, high-resolution, and mechanically robust bioelectronics via direct ink printing.