PROCEEDINGS ARTICLE | May 19, 2009
Proc. SPIE. 7362, Smart Sensors, Actuators, and MEMS IV
KEYWORDS: Gold, Thin films, Metals, Laser processing, Laser applications, Scanning electron microscopy, Infrared spectroscopy, Solids, Stereolithography, Liquids
Innovative surfaces are successful, if we succeed to put in the correct place the correct property with technological
efficiency. Until now, material surfaces can be systematically structured in different ways in order to fulfil chemical or
mechanical requirements such as corrosion protection or wear resistance for example. Moreover, the properties of
materials are strongly related to their microstructure as well as to their spatial distribution. For that reason, the design of
materials with tailored microstructures is a key for the functionalization of surfaces. This is possible by an artificial
fabrication technique called Laser Interference Metallurgy.
In this context, textured or functionalized surfaces are beneficial in overcoming stiction and adhesion in MEMS devices.
With regard to tribological applications, a systematic study of the effect of geometrically differing laser interference
patterns on the wetting behaviour of metallic gold thin films with a thickness of about 300 nm and 125 μm thick
polyimide foils should be presented. It could be shown that in case of gold films, a laser interference patterning
reinforces the hydrophilic sample behavior whereas the polyimide foils reveal a significant increase in hydrophobicity
after the laser patterning process. Both wetting regimes are advantageous under dry or lubricated friction conditions. The
corresponding geometrical limits of the abovementioned method concerning the structure depth, periodicity and pattern
form has been determined. All the samples have been characterized by scanning electron and focused ion beam
microscopy and white light interferometry. Additionally, IR spectroscopy has been applied to the polyimide samples in
order to separate topographic and chemical influences.
