Room‐Temperature‐Formed PEDOT:PSS Hydrogels Enable Injectable, Soft, and Healable Organic Bioelectronics

There is an increasing need to develop conducting hydrogels for bioelectronic applications. In particular, poly(3,4‐ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) hydrogels have become a research hotspot due to their excellent biocompatibility and stability. However, injectable PEDOT:PSS hydrogels have been rarely reported. Such syringe‐injectable hydrogels are highly desirable for minimally invasive biomedical therapeutics. Here, an approach is demonstrated to develop injectable PEDOT:PSS hydrogels by taking advantage of the room‐temperature gelation property of PEDOT:PSS. These PEDOT:PSS hydrogels form spontaneously after syringe injection of the PEDOT:PSS suspension into the desired location, without the need of any additional treatments. A facile strategy is also presented for large‐scale production of injectable PEDOT:PSS hydrogel fibers at room temperature. Finally, it is demonstrated that these room‐temperature‐formed PEDOT:PSS hydrogels (RT‐PEDOT:PSS hydrogel) and hydrogel fibers can be used for the development of soft and self‐healable hydrogel bioelectronic devices. A poly(3,4‐ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) suspension forms hydrogel at room temperature after being mixed with surfactants. Taking advantage of these room‐temperature formed hydrogels, various applications are presented including injectable conducting fillers, injectable conducting microfibers, and water‐healable conductors. These new demonstrations encourage further development of PEDOT:PSS hydrogels for potential biomedical applications.