JultikaUniversity of Oulu repository

In order to fulfill the increasing energy demand, several improvements can be done in already existing means of producing energy. Based on the idea of light harvesting, several main ideas of optimizing natural leaves (or even creating from a master), such as morphology, super-hydrophobity and waterproofing, among others, have been analyzed. Experimentally, it has been shown that by means of applying natural coatings of wax (from bilberry and lingonberry) onto the surface of silicon and PDMS the reflectance varies in the visible spectrum. In the case of silicon the reflectance decreased on average 17.5% in the case of the bilberry wax and 18.4% for lingonberry wax. For PDMS, the curves were more complex and implied an increase of reflectance of 1.3% for bilberry and 2.4% for lingonberry. Finally, a Scanning Electron Microscope imaging experiment was carried out, revealing that for a film coating of wax bigger specks formed (circa 0.1 mm), thus leading to the conclusion that a spin coating is the best option to achieve optimal properties, since the smaller specks would not override other applied coating and natural properties.