Conducting polymer hydrogels have gained attention in the bioelectronics field due to their unique combination of biocompatibility and customizable mechanical properties. However, achieving both excellent conductivity and mechanical strength in a hydrogel remains a significant challenge, primarily because of the inherent conflict between the hydrophobic nature of conducting polymers and the hydrophilic characteristics of hydrogels. To address this issue, this work proposes a simple one-step acid-induced approach that not only promotes the gelation of hydrophilic polymers but also facilitates the in situ phase separation of hydrophobic conducting polymers under mild conditions. This results in a distinctive bi-continuous phase structure with exceptional electrical property (906 mS cm-1) and mechanical performance (fracture strain of 1103%). The hydrogel forms robust percolating networks that maintain structural integrity under mechanical stress due to their entropic elasticity, providing remarkable strain insensitivity, low mechanical hysteresis, and an impressive resilience (95%). Electrodes fabricated from the conductive hydrogel exhibit stable and minimal interfacial contact impedance with skin (1-6 kilohms at 1-100 Hz) and significantly lower noise power (4.9 µV2). This work believes that the motion-insensitive characteristics and mechanical robustness of this hydrogel will enable efficient and reliable monitoring of biological signals, establishing a new benchmark in the bioelectronics.
Keywords: conducting polymers; hydrogel electrodes; motion artifacts; phase separation; wearable devices.
© 2024 Wiley‐VCH GmbH.