Design of Highly Conductive, Intrinsically Stretchable, and 3D Printable PEDOT:PSS Hydrogels via PSS-Chain Engineering for Bioelectronics
Jiawen Yu, Fajuan Tian, Wen Wang, Rongtai Wan, Jie Cao, Chen Chen, Dianbo Zhao, Jingcheng Liu, Jiang Zhong, Fu‐Cheng Wang, Qi Liu, Jingkun Xu, Baoyang Lu
Abstract
Poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS)-based hydrogels have emerged as ideal interfacing materials for bioelectronics because of their intriguing electrical, mechanical, and biological properties. However, the development of high-performance PEDOT:PSS-based hydrogels simultaneously achieving high conductivity, robust mechanical properties, and accessibility for advanced manufacturing technologies remains a critical challenge for further advancing such materials toward practical applications. Herein, we develop a highly conductive, intrinsically soft, tough yet stretchable PEDOT:PSS-based hydrogel via a simple PSS-chain engineering strategy of introducing thermally cross-linkable N -(hydroxymethyl)acrylamide segments. The resultant PEDOT:PSS hydrogel exhibits high electrical conductivity (1850 S m –1 ), high stretchability (>50%), low Young’s modulus (4 MPa), and superior toughness (400 kJ m –3 ), satisfying multiple property requirements for practical bioelectronic applications. Based on this material, we further develop a novel PEDOT:PSS ink with superior 3D printability for direct ink writing 3D printing, enabling us to facilely fabricate bioelectronic devices like soft skin electrodes comparable to commercial products via multi-material 3D printing.