Customizable Fabrication of 2D and Conformal Multielectrode Arrays for 3D Printed Organotypic Bioelectronic Interfaces

Organotypic 3D tissue models require precise electrophysiological interfaces to study function and disease. Multi‐electrode arrays (MEAs) are essential for recording and stimulation, yet conventional fabrication methods are costly and time‐intensive. This study demonstrates aerosol jet printing (AJP) of gold nanoparticles onto flexible polyimide substrates to produce fully gold, biocompatible MEAs for rapid customization of MEAs. Fabrication time is reduced from ≈320 min (photolithography) to ≈175 min, with minimal material waste. Printed electrodes achieve low impedance (0.05 kΩ µm − 2 at 1 kHz) with stable performance over 14 days. Coating with poly(3,4‐ethylenedioxythiophene) polystyrene sulfonate (PEDOT/PSS) increases charge injection capacity and maintains stability over 200 000 stimulation pulses. Cytocompatibility is confirmed through direct 3D bioprinting of C2C12 myoblast‐laden gelatin methacryloyl (GelMA) onto MEAs, achieving 70–80% viability. Electrical stimulation induces myoblast alignment, and extracellular recordings from primary cortical neurons and HL‐1 cardiomyocytes yield signal‐to‐noise ratios of 20.89 and 16.62 dB, respectively. Integration into 3D‐printed hydrogel conduits demonstrates conformal application and enhanced cell organization. These findings establish AJP as a scalable fabrication approach for customizable MEAs, supporting the development of advanced bioelectronic interfaces for organotypic tissue models.