Spatially resolved temperature measurement in fluids using confocal fluorescence microscopy
The increasing demand for technical parts with micro dimensions increasingly requires the use of manufacturing techniques such as laser chemical manufacturing (LCM), whose non-contact material removal is based on a localized chemical reaction with an electrolyte fluid. Current research focuses on improving the LCM surface quality, which depends mainly on the laser-induced surface temperature. To this end, research is currently being carried out on modelling the surface temperature and in-situ measurement of the surface geometry in liquids using confocal fluorescence microscopy (see Fig. 1). The geometry measurement is now to be extended to include the measurement of the process-relevant fluid temperature in order to optimize the LCM manufacturing quality on the basis of temperature modeling. Based on the determination of the fluorescence lifetime, which depends on the temperature of the fluorophore, the temperature distribution shall be determined spatially resolved during the geometry measurement.
The main task of the thesis is the development and construction of a detector system, which uses this measuring principle in combination with the confocal fluorescence microscope to measure the fluorescence lifetime of the fluid. The feasibility of the spatially resolved temperature measurement shall be demonstrated in first experiments. In the future, the temperature measurement will be combined with the existing geometry measurement to enable simultaneous in-situ measurement of both quantities.
Potential contents of the thesis can be:
- Development of a detector system for fluorescence lifetime measurement
- Integration into an existing confocal fluorescence microscope for the first experiments of spatially resolved temperature measurement in a fluid
- Development of measurement and evaluation strategies for the combination of fluorescence lifetime-based temperature measurement with existing geometry measurement