3D micropatterning of PEDOT:PSS/Gelatin conductive hydrogels via two-photon lithography for soft bioelectronics

Abstract The mechanical similarity between bioelectronic platforms and native tissue microenvironments is critical for successful cell-microdevice interfacing. Advances in high-resolution microfabrication have enabled the creation of 3D conductive microstructures; however, these approaches typically yield to structures that are electrically active but mechanically stiff relative to biological tissues. In this work, we present a strategy for the fabrication of soft 3D bioelectronic interfaces by blending PEDOT:PSS with a methacrylate-modified gelatin and leveraging two-photon polymerization lithography for micropatterning. Incorporating the conducting polymer into the hydrogel matrix resulted in reduced electrical impedance and exhibited soft mechanical properties both at the macro- and micro-scale. Here, the conductive hydrogel blends have been 3D printed, their versatility was assessed through different geometries and were used for neuronal cell culture. This approach enables the fabrication of soft neural interfaces with biomimetic architectures, using multimaterial blends, supporting improved electrical and mechanical integration at the cell-electrode interface.