Photopolymerization is a technique used to create surface structures or microobjects from a photoresist. This process is started by illuminating the sample with a light of proper wavelength absorbed by the resist. After exposure, the sample is processed according to the type of the photoresist – be it heating, treating with developer or just washing the unaffected monomer with some reagent. Focused femtosecond laser beam with double wavelength can be used in the process. Short pulse length with high photon density starts two-photon absorption localized in the vicinity of focal point. The method resolution is thus increased and details with 1/10 micrometer size can be created. Moreover, very short laser pulse decreases the heat affected zone and the risk of thermal initiation is minimized. Manufacturing of larger structures composed of tiny details with two-photon photopolymerization is time-demanding process. Therefore, we have complemented the optical setup with spatial light modulator (SLM), which splits the incoming laser beam into several beams with holograms dynamically generated by a computer. Polymerization can be thus performed by multiple foci simultaneously which can be used to create separated microparticles or periodical surface structures. Additional speed improvement of the process can be substitution of static configuration, requiring sample replacement after each exposition, with continuous setup using microfluidic channel steadily supplied with photoresist transported to the active region of the sample.
| Identifer | oai:union.ndltd.org:nusl.cz/oai:invenio.nusl.cz:295651 |
| Date | January 2017 |
| Creators | Skalický, Jiří |
| Contributors | Pilát,, Zdeněk, Jákl,, Petr |
| Publisher | Vysoké učení technické v Brně. Fakulta chemická |
| Source Sets | Czech ETDs |
| Language | Czech |
| Detected Language | English |
| Type | info:eu-repo/semantics/masterThesis |
| Rights | info:eu-repo/semantics/restrictedAccess |
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