Mechanically Robust and Electrically Conductive Hydrogels with Hybrid Nanofibrous Network

Conductive hydrogels are promising candidate materials for the construction of soft bioelectronics. Their mechanical flexibility, water content, and porosity approach those of biological tissues, providing a compliant interface between the human body and electronic hardware. However, most of available conductive hydrogels exhibit poor mechanical properties, which hinders their application in durable bio-integrated systems. This presentation will highlight our recent works on aramid-nanofiber-based multifunctional hydrogels, which provide a combination of high strength, elasticity, and electrical conductivity. Highly branched aramid nanofibers afford a robust 3D framework resembling those in load-bearing soft tissues. When interlaced with polyvinyl alcohol and crosslinked with both non-covalent and covalent interactions, the nanofiber composites exhibit a high water content of ~80 wt%, strength of ~10 MPa, ductility of ~400%, and shape recovery of ~99.5% under 0.3 MPa of cyclic tensile stress. Mobile ions or conducting polymers infiltrated in the nanofibrous network impart a high electrical conductivity, enabling bioelectronic interfaces and large-strain sensors with stable operation. In addition, embedded silver nanoparticles could afford broad-spectrum antimicrobial activities, which is favorable for medical devices. The versatility of aramid-nanofiber-based composites suggests their further possibilities for functionalization and scalable fabrication toward sophisticated bioelectronic systems.