Direct laser writing (also known as multiphoton lithography) is similar to standard photolithography techniques, but it allows production of complicated 3D-structures with photopolymerization of certain photoresist via short light pulses of a well-defined wavelength. The key principal to produce submicron-scale features is the induction of a dramatic change in the solubility of the resist for appropriate developers .
However, such polymer resists often do not provide the desired properties to use in industry, where high pressures and temperatures are involved. On the other hand, a completely inorganic material which is resistant to these conditions can not undergo multiphoton lithography, since there are no monomers which can be photopolymerised. ORMOCERs (organically modified ceramics) are photosensitive sol-gel hybrid materials and represent an attractive hybrid between organic and inorganic materials and, subsequently, they inherit the mechanical and electronic properties of ceramics, as well as the possibility for photopolymerization from conventional resists .
While the technology of multiphoton lithography is widely investigated, no specific research is done for the use of this technology in the chemical process technology.
Within this project, you will investigate fabrication of structures made of ORMOCERs, with further application in catalysis support. You will also be encouraged to produce multilayer structures with typical catalytic support materials, such as alumina and silica. In the research that will be conducted, the question is which materials could be used for performing multiphoton lithography and if these materials can withstand severe process conditions, focussed on elevated temperatures.
- Anscombe, N. (2010). Direct laser writing. Nature Photonics, 4(1), 22–23. https://doi.org/10.1038/nphoton.2009.250
- Haas, K. H., & Wolter, H. (1999). Synthesis, properties and applications of inorganic-organic copolymers (ORMOCER®s). Current Opinion in Solid State and Materials Science, 4(6), 571–580. https://doi.org/10.1016/S1359-0286(00)00009-7
- LaFratta, C. N., Fourkas, J. T., Baldacchini, T., & Farrer, R. A. (2007). Multiphoton fabrication. Angewandte Chemie - International Edition. https://doi.org/10.1002/anie.200603995