Local Metal Deposition on Hydrogels Using Micro-Plasma-Bubbles

We propose a local metal deposition method that enables patterning on hydrogels using micro-plasma-bubbles (MPBs). In this method, we generate MPBs in a solution containing metal ions. Local metal deposition on hydrogels has a wide range of possibilities, however, it has been a considerable challenge since appropriate methods have not been established. In this work, we reduced metal ions in an electrolyte solution and successfully deposited several kinds of metals such as copper, nickel, copper-nickel alloy, and even gold nanoparticles on hydrogels by using MPBs. These results show that the proposed method opens up new possibilities of an on-demand metallization process for hydrogels that can serve as soft actuators and electronics.