Nanodroplet-Confined Electroplating Enables Submicron Printing of Metals and Oxide Ceramics.

The fabrication of functional micro- and nanoelectronic devices requires the deposition of high-quality materials from different electronic material classes, such as conductors, semiconductors, and insulators. Establishing ultrahigh-resolution additive manufacturing as a viable addition to existing fabrication methods requires the combinatorial additive deposition of different electronic material classes. However, current techniques do not provide such a capability. Here, we demonstrate that droplet-confined electroplating, an ultrahigh-resolution additive manufacturing technique initially developed for metals as electrohydrodynamic redox printing (EHD-RP), allows the direct deposition of not only many metals but also metal oxides. Particularly, we demonstrate that applying fundamental electrochemical principles in combination with on-the-fly switching of the deposited material allows for the direct codeposition of metals, metal hydroxides, and metal oxides. Our results demonstrate the feasibility of leveraging simple water-based electrochemical concepts to produce intricate and multimaterial structures at the nanoscale.