Department of Mechanical Engineering, The University of Hong Kong, Hong Kong SAR, China.
Department of Biomedical Sciences, City University of Hong Kong, Hong Kong SAR, China.
Nat Commun. 2023 Feb 10;14(1):759. doi: 10.1038/s41467-023-36438-8.
Electroconductive hydrogels have been applied in implantable bioelectronics, tissue engineering platforms, soft actuators, and other emerging technologies. However, achieving high conductivity and mechanical robustness remains challenging. Here we report an approach to fabricating electroconductive hydrogels based on the hybrid assembly of polymeric nanofiber networks. In these hydrogels, conducting polymers self-organize into highly connected three dimensional nanostructures with an ultralow threshold (~1 wt%) for electrical percolation, assisted by templating effects from aramid nanofibers, to achieve high electronic conductivity and structural robustness without sacrificing porosity or water content. We show that a hydrogel composed of polypyrrole, aramid nanofibers and polyvinyl alcohol achieves conductivity of ~80 S cm, mechanical strength of ~9.4 MPa and stretchability of ~36%. We show that patterned conductive nanofiber hydrogels can be used as electrodes and interconnects with favorable electrochemical impedance and charge injection capacity for electrophysiological applications. In addition, we demonstrate that cardiomyocytes cultured on soft and conductive nanofiber hydrogel substrates exhibit spontaneous and synchronous beating, suggesting opportunities for the development of advanced implantable devices and tissue engineering technologies.
导电水凝胶已被应用于可植入生物电子学、组织工程平台、软驱动器以及其他新兴技术中。然而，实现高导电性和机械鲁棒性仍然具有挑战性。在这里，我们报告了一种基于聚合物纳米纤维网络混合组装来制备导电水凝胶的方法。在这些水凝胶中，导电聚合物通过芳纶纳米纤维的模板效应，自组装成具有超低电渗阈值（1wt%）的高度互联的三维纳米结构，从而在不牺牲孔隙率或含水量的情况下实现高导电性和结构鲁棒性。我们表明，由聚吡咯、芳纶纳米纤维和聚乙烯醇组成的水凝胶具有约 80 S cm 的电导率、9.4 MPa 的机械强度和~36%的拉伸性。我们表明，图案化的导电纳米纤维水凝胶可用作电极和互连物，具有有利的电化学阻抗和电荷注入能力，适用于电生理应用。此外，我们证明了在柔软且导电的纳米纤维水凝胶衬底上培养的心肌细胞表现出自发和同步跳动，这为开发先进的可植入设备和组织工程技术提供了机会。
