A further option for producing biocompatible (micro)structures with specific mechanical characteristics is to use multiphoton polymerization (MPP). This high-resolution 3D printing process can polymerize both monomers and proteins either with or without initiators. It uses highly focused ultrafast laser radiation to deliver a nonlinear absorption process in a highly localized volume pixel (voxel). The resolution of the structures produced is in the sub-micrometer range.
In contrast to processes that are based on linear absorption, here only the focus volume is affected. This opens the door to new process opportunities such as the manufacture of microstructures in closed systems, for instance in microfluidics components. However, the high resolution demands a lower processing speed. At Fraunhofer ILT, we combine multi- and single-photon techniques to harness the advantages of both processes and compensate for their disadvantages.