Willy-An Silvius and Micha Mulder
Near the German border in the east of The Netherlands you will find a micro and nano fluidic cluster around the University of Twente in Enschede. Its campus houses the High Tech Factory and the Nanolab. The High Tech factory offers cleanrooms and lab facilities for rent for companies and start-ups. The Nanolab facilities are part of Mesa+ research Institute, one of the world’s largest nano technology research institutes; and it’s the largest research institute in this field in the Netherlands. This is the place where Micronit Microfluidics has its roots and has become a fully-fledged R&D and manufacturing facility in the field of micro fluidics over the last decade. In its 300m2 cleanroom, equipped with state-of-the-art micro machinery, processes like wet-etching, aligning, metrology, scribing and dicing take place. These processes are performed mainly on glass wafers (square and round) in diameters/dimensions of 100, 150 and 200 mm for both the micro fluidics and MEMS markets. The combination of these cleanroom processes and the knowledge of the behaviour of micro fluidics makes it possible for Micronit Microfluidics to provide a total solution.
Powderblasting
Powderblasting is a flexible, cost-effective and accurate technique to create fluidic channels and interconnections, because of the use of a lithographic mask position accuracy is very good, within 2 μm. The feature size accuracy is about 25 μm. Further powderblasting makes it possible to be flexible on the layout and design of the holes and channels.
The first step in this process is to transfer the design of the channels and holes onto the glass by means of photolithography: a photoresist film is laminated on the glass and the mask with the design is positioned above the film. The film is then illuminated with UV light through the mask. Illuminated areas will be removed from the glass during development. During the exposure of the wafer to the powder the areas not covered by film are etched, while the covered areas deflect the powder. The etch rate and depth can be controlled by controlling the time and particle speed.