New opportunities with true 3D microfluidics

Various 2.5D and 3D microfluidic elements such as nozzles, filters, mixers and capillary pumps become feasible thanks to the advanced 3D microfabrication capabilities of Nanoscribe systems. Tailored topographies and smooth surfaces can be produced with high definition. Also sharp micro-needle arrays can be created to control small quantities of liquids, e.g., for precise drug delivery.

Our 3D printers offer the highest resolution for additive manufacturing available on the market, achieving minimal feature sizes in the submicron range. The additive approach allows to fabricate microchannel master molds in 2D and 2.5D and to directly print complex microfluidic 3D structures, such as a filigree microfluidic mixer, even in fully sealed microchannels.

For example, mastering and in-chip 3D printing are combined to miniaturize a wet-spinning process in a microfluidic chip: First, a positive master of the microfluidic channel system is printed. Then, by casting PDMS over the printed channels, a negative mold of the channel structures is fabricated. This PDMS slab is sealed by adhering it to a microscope slide using oxygen plasma. The channels are then filled with photoresin, followed by an in-chip 3D printing step. Using Two-Photon Polymerization and an objective lens to focus the laser beam inside the channel, a 3D micronozzle is printed.