About this role
We offer a PhD position in the research group of Dr. Frederik Kotz-Helmer, which is embedded within the NeptunLab led by Prof. Bastian E. Rapp at the Department of Microsystems Engineering (IMTEK), University of Freiburg. NeptunLab is a highly interdisciplinary research environment focusing on the development of novel materials, manufacturing technologies, and processes for industrial applications. Research from the NeptunLab has been published in leading international journals, including Lab on a Chip, Advanced Materials, Angewandte Chemie, and Nature, and has received attention from national and international media outlets such as the BBC, The New York Times, and the Discovery Channel. Glass is an essential engineering material for applications ranging from optics and photonics to microtechnology and high-performance components. However, conventional glass manufacturing technologies strongly limit the geometries that can be produced and often require complex and energy-intensive processing routes. Within this PhD project, a novel extrusion-based manufacturing technology for glass will be developed. The approach is based on highly filled thermoplastic nanocomposites containing silica nanoparticles dispersed in a polymeric binder system. These materials are shaped in the polymeric state by extrusion and subsequently converted into dense, transparent glass through debinding and sintering. A major focus of the project will be the development of thermoplastic nanocomposites with tailored rheological and mechanical properties. Polymer composition, molecular weight, particle loading, particle dispersion, and processing conditions will be systematically investigated to establish relationships between material formulation, flow behavior, extrusion stability, and the geometry of the resulting components. Structured extrusion dies will be used to directly manufacture complex cross-sectional geometries, providing a new route toward continuous manufacturing of structured glass components. The successful candidate will work at the interface of materials science, polymer processing, rheology, nanocomposites, and glass technology. The project combines fundamental materials research with the development of a new manufacturing process and therefore provides substantial freedom for both scientific investigation and technology development. Developing highly filled thermoplastic silica nanocomposites for extrusion-based glass manufacturing. Designing polymer binder systems with tailored rheological, mechanical, and debinding properties. Developing and optimizing extrusion processes for complex and microstructured geometries. Investigating the relationship between extrusion parameters, die geometry, material flow, and dimensional accuracy. Designing and evaluating structured extrusion dies for the continuous manufacturing of complex glass components. Characterizing nanocomposites and glasses using techniques such as SEM, XRD, FTIR, Raman spectroscopy, rheology, thermal analysis, and optical characterization. Establishing quantitative material-process-structure relationships for extrusion-based glass manufacturing. Presenting research results at international conferences and publishing findings in peer-reviewed journals. Master’s degree/Bachelor’s degree/Studies in Material Science, Mechanical Engineering, Process Engineering or related subjects Profound knowledge of polymer chemistry, material science and processing is required Knowledge of glass science, ceramic processing or polymer extrusion are/is beneficial. Excellent academic track record Excellent English skills in reading and writing You should be a team player with ambitions who can conduct research projects independently You should be able to structure and document your work properly You should be a creative mind without causing excessive chaos around you An interdisciplinary work environment with a team of motivated scientists that strive to develop clever solu...