Robust Polyimide/Graphene Composites as Electrically Functional Materials for Space-Compatible Biomedical Applications

Polyimide-based composites with graphene nanoplatelet (GNP) fillers are investigated as multifunctional materials for potential space-compatible biomedical monitoring. These composites are designed to combine the intrinsic high thermal and chemical stability of polyimides, as well as their well-established radiation resistance reported in the literature, with the electrical functionality of graphene. PI/GNP membranes are fabricated by casting dispersions of graphene nanoplatelets within the polyimide solution, using a green and bio-based solvent (dimethyl isosorbide), followed by thermal treatment in vacuum. The effect of UV-C irradiation is investigated as a sterilization-relevant stress condition, showing that the PI/GNP composites retain their main chemical and surface characteristics after exposure. In addition, irradiation is associated with an improvement in the electrical response, suggesting that the conductive network formed by graphene nanoplatelets remains effective after treatment. Overall, this study highlights the PI/GNP composites as robust and electrically functional candidate materials for dry electrode applications in harsh environments. By combining chemical stability, thermal resistance, a stable surface and electrical conductivity, these membranes emerge as promising candidates for future health monitoring applications on Earth and during long-term missions in space.