Aerosol jet co-printing for flexible and conductive protein–metal electrodes

We report a rapid, single-step aerosol jet co-printing method for flexible, conductive collagen–silver electrodes. By simultaneously depositing collagen and silver nanoparticle inks, we achieve tunable conductivity and biocompatibility using short (5 min) low-temperature (150 °C) curing. The resulting composites exhibit resistivity as low as ≈10−6 Ωm, maintain conductivity under mechanical flexure, and preserve partial protein structure for up to 3 weeks in physiological media. Cell culture studies confirm reduced cytotoxicity at high collagen content, defining a processing window that balances electrical and biological performance. These findings demonstrate that aerosol jet printing co-printing offers a scalable and versatile fabrication strategy for next-generation flexible bioelectronic devices, with electrical and biological performance that can be tuned through material composition and processing parameters.