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Ultrashort laser pulses with durations in the fs- to ps-range were used for large area surface processing of steel aimed at mimicking the morphology and extraordinary wetting behaviour of bark bugs (Aradidae) found in nature. The processing was performed by scanning the laser beam across the surface of initially polished flat sample surfaces. A systematic variation of the laser processing parameters (peak fluence, scan velocity, line overlap) allowed the identification of different regimes associated with characteristic surface morphologies (laser-induced periodic surface structures (LIPSS), grooves, spikes, etc.). Additionally, we show that different laser processing strategies, varying laser wavelength, pulse duration and repetition rates, allowed to achieve a range of morphologies that resemble different structures found in bark bugs. For identifying the ideal combination of parameters for mimicking bug-like structures, the surfaces were inspected by optical and scanning electron microscopy.
Complementary to the morphology study, the wetting behaviour of the surface structures for water and oil was examined intensively in terms of philic/-phobic nature and fluid transport. With these results in hand, tribological tests were carried out investigating the wear resistance of the laser-induced nano- and microstructures. Our results demonstrate a route towards reproducing complex structures inspired by nature and their functional response in technologically relevant materials.
Applications of laser-induced periodic surface structures (LIPSS, ripples) upon irradiation of solid materials by fs-laser pulses are reviewed. This includes the colorization of technical surfaces, the control of surface wetting, the mimicry of the natural texture of animal integuments for realizing specific fluid transport functionalities, the tailoring of surface colonization by bacterial biofilms, and the improve-ment of the tribological performance of nanostructured metal surfaces.
Applications of femtosecond laser processed surfaces are reviewed. This includes the colorization of technical surfaces, the control of surface wetting, the tailoring of surface colonization by bacterial biofilms, the reduction of cell adhesion on novel pacemakers, and the improvement of the tribological performance of nanostructured metal surfaces.
Nature provides countless examples of surface structures featuring extraordinary properties such as directional fluid transport. In order to mimic the morphology and outstanding wetting behaviour of bark bugs, ultrashort laser pulses with durations in the fs- to ps-range were employed for large area surface processing of steel. By scanning the laser beam across the surface of initially polished flat sample surfaces and systematically varying the laser processing parameters (peak fluence, scan velocity, line overlap), different regimes associated with characteristic surface morphologies (laser-induced periodic surface structures (LIPSS), grooves, spikes, etc.) could be identified. Additionally, different laser processing strategies were applied, varying laser wavelength, pulse duration and repetition rates, which allowed to achieve a range of morphologies that resemble different structures found on bark bugs. For identifying the ideal combination of parameters for mimicking such bug-like structures, the surfaces were inspected by means of optical and scanning electron microscopy.
Complementary to the morphology study, the wetting behaviour of the surface structures for water and oil was examined intensively in terms of fluid transport and philic/-phobic nature. Additionally, with these results in hand, tribological tests investigating the wear resistance of the laser-induced nano- and microstructures were carried out. Our results demonstrate that the functionality of surface structures found in nature could be transferred to technologically relevant materials, such as steel, providing a huge potential for industrial applications for instance in friction and wear reduction.