Preparation of two-dimensionally patterned layers of functionalised calcium phosphatenanoparticles by laser direct writing

Abstract

Calcium phosphate nanoparticles were functionalised using suitable polymeric additives and electrophoretically deposited on titanium and silicon substrates. Subsequently the coated substrates were patterned with a focused beam of an argon ion laser at a wavelength of 514 nm. Depending on the incident laser power and the writing speed, different processes were observed. At high laser power and writing speed, the particle layer was locally removed down to the substrate (“laser cleaning”). In contrast, at low laser power and writing speed, the particles melted and formed larger structures. The width of the laser written lines is of the order of the laser spot size (about 3 µm). This approach opens a way to two-dimensionally structured layers of nanoparticles with a predefined thickness.