Fabrication and Testing of Microstructures and Composites by Means of Multi-Photon Lithography

Advances in semiconductor manufacturing technology lead to a continuous integration of electronic components on a decreasing footprint and thus to miniaturization of electronic devices. Equivalently, small-scale additive manufacturing, such as modern multi-photon lithography, will enable fast, precise and versatile production of complex-shaped appliances on a microscopic length scale. Although a comparably young technique compared to different industrial manufacturing technologies, developments of today already revolutionize scientific fields, such as photonics, biotechnology, medicine and many more. With this respect, the present thesis incorporates two major focus areas. The first one is to develop characterization techniques directly utilizing multi-photon lithography manufactured specimens to test obtained photo-polymers, as well as composite-system properties, such as adhesion. Therefore, the common cantilever bending specimen geometry was adapted for additive manufacturing and additionally, a novel geometry was developed, which facilitates tensile experiments via a push-to-pull approach. Both were utilized for in situ scanning electron microscope investigations and in a high-throughput application to perform advanced experimental characterizations. The push-to-pull structures incorporating various double-edge-notched tensile specimen geometries enabled an essential-work-of-fracture characterization, whereby several hundred individual specimens were tested. Multiple single-edge-notched bending specimens were equipped with pores at defined positions to study crack deflection at material inhomogeneities through in situ scanning electron microscope experiments. The second focus was laid on adhesion mediating functionalization treatments and the deposition of metallic coatings, which are crucial aspects to produce function-added composite structures. In this regard, the effect of functional silanization to increase adhesion of multi-photon lithography-manufactured parts was investigated via micro-tensile specimens. By another work, the film quality of a physical-vapor-deposition-derived metallic film on multi-photon-lithography structures was assessed on one hand, and on the other, differently structured metalized electrodes were produced. These were additionally investigated with regards to the hydrogen evolution activity to quantify the effect of surface structuring. Taken together, new versatile methodological approaches were employed for investigating material and interface characteristics, by exploiting the unique possibilities of multi-photon lithography manufacturing. Thus, the results of all work performed open up new possibilities with regards to miniaturized device design.