Oriented gold ripple-like structures on poly-l-lactic acid

In this paper chemical, morphological, electrical and biological properties of poly-l-lactic acid thin films with gold nanolayers were studied. These samples were examined as-sputtered and annealed at glass transition temperature. Morphological changes of poly-l-lactic films introduced by annealing were studied by means of atomic force microscopy. This method showed formation of oriented ripple-like structures on the surface of the film. X-ray photoelectron spectroscopy, goniometry, ellipsometry, sheet resistance measurement and electrokinetic analysis were used to determine distribution of gold on the surface. Combined data suggests that these ripple-like structures were formed by gold lines with insulating polymer gaps in between. These lines show preferential orientation over large areas and under proper conditions offer simple way to form electrically anisotropic material on large scale. Also cytocompatibility was studied showing increased cell adhesion and proliferation of mouse embryonic fibroblasts offering another use for these easily formed structures.