Next alchemy: nanoparticle exothermic alloying chemistry for producing tall on-chip cast metal microstructures

This paper reports on NExt AlChemy, a new process that produces tall, on-chip cast bronze microstructures. Powdered CuO and Al, ignited in a graphite crucible produce a highly exothermic chemical reaction, resulting in molten aluminum bronze. This superheated fluid (>3000 K) having less surface tension than standard molten bronze, flows into a micromachined and reusable graphite mold. Cu or Al nanoparticles in the micromold can be used to moderate the total heat; the structures are self welded to a substrate without damage.