Fabricating a 3D hollow fibre for a micro fluidics system

Fabricating a 3D hollow fibre for a micro fluidics system

Hollow fibre sequence made from OrmoComp® with pores (pore diameter: 28.5 µm) (right)
© Fraunhofer IWS Dresden

Hollow fibre sequence made from OrmoComp® with pores (pore diameter: 28.5 µm) (right)

Schematic image of a bioreactor system (above); via 2PP generated, branched hollow fibre made of OrmoComp® (length: 3.6 mm, outer diameter: 150 µm, inner diameter 90 µm) (below)
© Fraunhofer IWS Dresden

Schematic image of a bioreactor system (above); via 2PP generated, branched hollow fibre made of OrmoComp® (length: 3.6 mm, outer diameter: 150 µm, inner diameter 90 µm) (below)

For cultivating various human cells in bioreactor systems the maintenance of the biological micro milieu via artificial vascular systems similar to human vasculature poses a great challenge. To ensure an ideal supply of oxygen and nutrient it is beneficial to embed a branched network of hollow fibers by using a polymer, which is linked via 2PP at ambient temperature.

The fabrication of 3D-structures is carried out with a collimated beam of a titan-sapphire laser which focuses extremely short infrared light pulses through an objective into a liquid OrmoComp®-solution. To produce the hollow fiber the focus is moved computer controlled within the photopolymer in x-, y-, and z-direction with 105 mW median laser power and 5.0 mm/s speed based on a three dimensional CAD-model.

This procedure distinguishes itself by its high flexibility, because any complexly shaped, three dimensional geometries can be realized. 2PP can potentially be applied to micro optics to build waveguide structures or micro lenses, to micro fluidics to fabricate micro pumps and -valves as well as to tissue-engineering to produce scaffolds.