Ramachandramoorthy, Rajaprakash; Mieszala, Maxime; Manzano, Cristina V.; Maeder, Xavier; Michler, Johann; Philippe, Laetitia
Applied Materials Today 20 (2020)
Given the push towards miniaturization in electronics it is vital to develop techniques capable of fabricating metal microarchitectures. Unfortunately, owing to the resolution limits macroscale additive manufacturing techniques cannot be used to manufacture mesoscale parts with sub-micron resolution. Here we present a novel dual-templating technique capable of producing damage-free nanocrystalline nickel inverse opal based microarchitectures. This technique involves the four sequential steps: fabrication of UV lithography based SU-8 polymer molds with the shape of the microarchitecture required, infiltration of the SU-8 mold with polystyrene beads, electrodeposition of nickel into the mold and finally reactive ion etching of the dual polymer supports. We demonstrate that this technique could be used to create ideal mechanical test-beds such as damage-free metal micropillars. Subsequently, the dense Ni and porous Ni inverse opal micropillars were mechanically tested to show that the properties of nickel inverse opal foams can be tailored by varying the combination of grain size (intrinsic effect) and ligament size (extrinsic effect).