Laser structuring and modification of surfaces for chemical and medical micro components
In the production of micro devices for applications in chemistry, biotechnology and medical technologies surface properties become more and more important The microscale topography and surface chemistry have influence on wetting properties and cell behavior. Therefor the design of material surface determines the success of artificial devices in contact with biological systems. For applications in the field of medical implants laser technologies have been developed for micro structuring of polymers to modify the surface properties with respect to wettability and controlled cell growth. The technology is based on excimer laser treatment of polymer surfaces using laser wavelength 193 nm (ArF) with different fluences and cumulated energies. Depending on the processing parameters and examined polymers either hydrophobic or hydrophilic surfaces can be increased. The water contact angle of polydimethylsiloxane (PDMS) for example can be increased from 113° to approx. 150° so that the surface exhibits the so called lotus effect. The laser generated micro patterns reveal influence on cell density and cell distribution which can be used for cell guidance. Results for cell growing experiments are shown for different polymers.