Three dimensional microfabrication by localized electrodeposition and

Abstract

Embodiments of the present invention provide a new method for producing a three dimensional object, particularly suited to microfabrication applications. The method includes the steps of providing a substrate with a conducting interface, an electrode having a feature or features that are small relative to the substrate, and a solution. The solution has a reactant that will either etch the substrate or deposit a selected material in an electrochemical reaction. The electrode feature is placed close to but spaced from the interface. A current is passed between the electrode and the interface, through the solution, inducing a localized electrochemical reaction at the interface, resulting in either the deposition of material or the etching of the substrate. Relatively moving the electrode and the substrate along a selected trajectory, including motion normal to the interface, enables the fabrication of a three dimensional object. In an alternative embodiment, current is passed through an orifice placed close to but spaced from the substrate surface, and may be accompanied by forced convection through the orifice. The method provides the potential to fabricate using many materials, including metals, alloys, polymers and semiconductors in three dimensional forms and with sub-micrometer spatial resolution.