Non-lithographic fabrication of metallic micromold masters by laser machining and welding

A non-lithographic process of rapidly fabricating metallic micromold masters for the manufacture of disposable polymer microfluidic devices is presented in this paper. The developed technique exploits the precision material removal capabilities of industrial lasers to cut accurate profiles of microfeatures (e.g., liquid flow microchannels, reservoirs, passive micromixers) from thin metallic sheets. The machined micropatterns are then laser welded onto a metal substrate to form the final functional mold master. Multiple versions of the functional device are replicated from the assembled master by either soft molding polydimethylsiloxane or hot embossing polymethyl methacrylate. Several metallic micromold masters and polymer replicas are tested for dimensional accuracy and surface roughness to verify the developed microfabrication process.