Three-Dimensional Photonic Structures Fabricated by Two-Photon Polymerization for Microfluidics and Microneedles

Polymer micro- and nanostructures with various geometries, such as lines, gratings, woodpiles or dots, can be written onto a transparent substrate by the technique of two-photon polymerization, i.e. focusing a femtosecond laser into a liquid acrylate based resin containing a photo-initiator. The microstructures can be also employed to mimic features found in nature for controlled wetting or liquid transport. Similar structures can be implemented into channels of microfluidic devices to control the transport of fluids herein. In preliminary experiments, we were able to produce microneedles ornamented with microstructures which would facilitate the transport of an aqueous liquid to the needle tip.