The templated assembly of highly faceted three-dimensional gold microstructures into periodic arrays

A templated assembly route has been devised which sees the formation of periodic arrays of gold microstructures on oxide substrates. The route, which combines elements of subtractive transfer patterning and templated dewetting, involves the placement of an electroformed nickel mesh in conformal contact with a continuous gold film. When heated, the gold beneath the grid selectively attaches to it due to a surface energy gradient which drives gold from the low surface energy oxide surface to the high surface energy nickel mesh. With this process being confined to areas under and adjacent to the mesh, the underlying gold film eventually ruptures at well-defined locations to form isolated islands of gold which subsequently dewet. Removal of the grid reveals a periodic array of three-dimensional highly-faceted gold microstructures. This templated assembly route is demonstrated for the (100)-, (110)- and (111)-surfaces of MgO and MgAl2O4 where it is observed that the faceting is strongly influenced by both the substrate and its crystallographic orientation.

► Discovery of an unconventional patterning technique for metal films. ► An assembly route uniting aspects of transfer patterning and templated dewetting. ► Templated assembly of substrate-based periodic arrays of Au microstructures. ► Formation of 3-dimensional highly-faceted Au microstructures on MgO and MgAl2O4. ► Faceting influenced by the crystallographic orientation of the substrate.