Functional inorganic thin films
Hyperspectral imaging combines two-dimensional imaging and spectroscopy. A hyperspectral image therefore includes a third dimension, which represents the optical spectrum in each pixel. One approach to realize a hyperspectral imaging system is to combine a broadband camera sensor with a tunable optical bandpass filter.
At NanoSYD, we are developing optical filters for thermal hyperspectral imaging applications based on a Fabry Perot interferometer principle. Two partially transmitting mirrors are realized as multilayer stacks of high and low refractive index materials. The mirrors form an optical cavity with a width carefully controlled by piezo elements. These enable the scanning of the center wavelength of the optical filter which, combined with a broadband camera sensor, realizes a hyperspectral imaging system. The thin films are deposited by various physical vapor deposition techniques and are studied by a range of experimental techniques incl. ellipsometry, SEM, energy-dispersive X-ray spectroscopy, FTIR, atomic force microscopy and more.
Moreover, we also have activities relating to the development of advanced materials for high-temperature strain gauges. The thin-film materials are deposited by a reactive sputtering process, which can enable the composition and the morphology of the deposited films to be varied over a wide range. The thin films are studied by different experimental techniques incl. ellipsometry, energy-dispersive X-ray spectroscopy, atomic force microscopy, and electrical and electromechanical measurements.
NanoSYD members working within this research area
Methodologies for Hyperspectral Thermal Imaging. Innovation Fund Denmark, Industrial PhD project in collaboration with Newtec Engineering A/S, 2018-2021.
Thin film strain gauges for high temperature applications. Innovation Fund Denmark, Industrial postdoc project in collaboration with Danfoss A/S, 2013-2015.
Acquisition and Analysis of Hyperspectral Thermal Images for Sample Segregation, A. C. L. Jørgensen, J. Kjelstrup-Hansen, B. B. E. Jensen, V. Petrunin, S. F. Fink and B. Jørgensen, Applied Spectroscopy, in print, DOI: https://doi.org/10.1177/0003702820972382
Three-point bending setup for piezoresistive gauge factor measurement of thin-film samples at high temperatures, N. D. Madsen and J. Kjelstrup-Hansen, Review of Scientific Instruments. 88, 015001 (2017)
Titanium Nitride as a Strain Gauge Material, N. D. Madsen, M. Hausladen, S. Chiriaev, P. Johannesen, Z. E. Fabrim, P. F. P. Fichtner and Kjelstrup-Hansen, J., I E E E Journal of Microelectromechanical Systems, 25, 4, 683 (2016)