282404 Laser- Drawn Features On Nanoparticle Films
Laser- Drawn Features on Nanoparticle Films
Sanjeev Kumar Kandpal, Kody Allcroft, Michael D. Mason, Douglas W. Bousfield, David J. Neivandt
Department of Chemical and Biological Engineering, University of Maine, Orono, USA.
Nanoparticles have found application in many fields because of their unique physical and optical properties. One specific property is the photo-thermal activity of plasmonic nanoparticles that relates to the particles ability to convert light energy into thermal energy. This property gives rise to potential applications for photothermal imaging, phtothermal cancer therapy, thermo-photovoltaics, optical storage and nano fabrication. In the present work, the goal is to generate fine scale structures on surfaces after films of these particles are exposed to laser light. Silver nanoparticles are used because of their high photon to thermal conversion efficiency. These nanoparticles were mixed with polyvinyl alcohol. A thin film was coated on glass substrate. Photons from a laser are absorbed by silver nanoparticles and converted to heat. The heat generated from nanoparticle melts the matrix around the particles and the particles themselves causing them to fuse together to form structures. We were able to draw features with a size range of 25µm. An atomic force microscope revealed that the structures can have dimensions in the vertical direction of 8 mm. An interesting fluorescence property of these laser drawn structures is generated. This seems to come from some chemical change of the dispersants used in the production of the nanoparticles. The mechanism for these photo generated features will also be explored.
Keyword: Photothermal, Fluorescence, Liquid melt ejection, Optical trapping, Sintering.