Electrocapillary Plating-An Innovative Method of Creating Nanostructures Enhances the Working Performance of Implantable Bioelectrodes

The current optimization of implantable electrodes focuses on reducing impedance and improving anti-inflammatory properties. The fabrication of nanostructures on electrode surfaces is a promising strategy for reducing impedance while also minimizing interference from the array of immune cells that cause foreign body reactions. Electrochemical deposition is a common method for creating nanostructures. However, the generation of impurities that are difficult to remove during the preparation process is unavoidable. Herein, we develop a simple, economical, and stable method, namely, electrocapillary plating, to create nanostructures on the electrode surface based on the electrocapillary phenomenon and electrochemical deposition without introducing impurities. This technology enables the fabrication of various nanostructures at different current densities and pH values. The process and mechanism of structure formation are investigated through simulations, which show that the conductive droplets undergo droplet climbing and nanostructure deposition due to the electrocapillary phenomenon and electrochemical deposition. Compared to traditional plating and control groups, the Electrocapillary plating-modified electrode demonstrates reduced impedance, lower protein adhesion, and greater tolerance to changes in the physicochemical environment. The in vitro and in vivo biological experiments verify that the Electrocapillary plating modified electrode shows the properties of bactericidal, pro-tissue repair and inhibition of the inflammatory response. These results highlight the potential of Electrocapillary plating as a novel strategy to optimize electrode performance in the field of implantable bioelectrodes. In addition, Electrocapillary plating, as an innovative surface modification technology, can create nanostructures of different metals and even further modulate the surface morphology by means such as hydrogen reduction. It may have even wider applications in various fields such as electronics, medicine, energy, environment, and materials science.