Laser micro-milling for the fabrication of a microfluidic device mold

Microfluidic devices in polymeric materials can be achieved with high throughput by means of casting or injection molding. The proper functionality of such devices depends highly on the dimensional accuracy of the part, hence the mold that is used for production. Among different processes for mold production, laser micromilling stands as an appealing option as it provides means for non-contact machining. In this work, laser micromachining of D2 tool steel with a ns-pulsed fiber laser is investigated. The machining strategies for deep engraving to achieve high surface quality and sharp corners are studied. A machining strategy is identified for realizing a mold for the production of a microfluidic device for hydrodynamic particle separation based on size.