Conversion of Biopolymer to UV‐Cross‐Linkable Conductive Ink with High Conductivity, Biocompatibility, and Biodegradability

Abstract Biocompatible, sustainable, and conductive inks are of special interest and are highly valued in the printable bioelectronics. However, the conventional inks, which increase electrical conductivity by mixing metal particles or graphene, can cause long‐term damage when applied to the body and environment. Herein, a method for creating a stable matrix based on a UV‐cross‐linkable polymer to which a conductive polymer can be grafted is investigated to solve the above problems by recycling biomass. Through this, it is possible to achieve high conductivity using only biocompatible and sustainable polymers. Here, conductive inks for printable bioelectronics are developed by grafting polypyrrole on methacrylate‐modified sericin and poly(ethylene glycol) diacrylate (PEGDA). The highest electrical conductivity is achieved by adjusting the ratio of the pyrrole monomers polymerized on each polymer until the conductivity is optimized. Owing to the photoreactive nature of PEGDA, the prepared conductive inks are cross‐linked by UV light, thus giving them easy‐printing properties. The biodegradability, biocompatibility, and electrical properties of the printed patterns are systematically analyzed. This study has significant implications in the field of sustainable and printable bioelectronics as it has developed of a conductive ink with the biocompatibility, biodegradability, and high conductivity that is safer and simpler than conventional methods.