Electroforming of 3D microstructures on highly structured surfaces

Electrodeposition of photoresist on highly structured surfaces is combined with electroplating to fabricate three new types of advanced 3D metal microstructures. In one application, electroplated nickel cantilever arrays are formed on the sloped sidewalls of KOH etched silicon. The cantilevers are released by sacrificial etching of copper.

In another application it is shown how KOH etched silicon V-grooves can be patterned by electrodeposited photoresist to generate versatile 3D electroforming moulds. To demonstrate the potential of this technology, an innovative all-nickel cantilever structure with V-shaped cross section and integrated reflection mirror for optical readout has been fabricated.

Cantilevers with V-cross section can be designed to have significantly larger out of plane bending stiffness or higher resonant frequency compared to rectangular cantilevers with similar dimensions. A third application uses electrodeposited photoresist to fabricate copper solenoids on an oxidised silicon support.