TY - CONF A1 - Kirner, Sabrina V. A1 - Hermens, U. A1 - Winands, K. A1 - Mescheder, H. A1 - Florian, C. A1 - Solis, J. A1 - Siegel, J. A1 - Hischen, F. A1 - Baumgartner, W. A1 - Skoulas, E. A1 - Mimidis, A. A1 - Stratakis, E. A1 - Spaltmann, Dirk A1 - Krüger, Jörg A1 - Bonse, Jörn T1 - Mimicking bug-like surface structures and their fluid transport produced by ultrashort laser pulse irradiation of steel N2 - 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. T2 - E-MRS Spring Meeting 2017, Symposium X: New frontiers in laser interaction: from hard coatings to smart materials CY - Strasbourg, France DA - 22.05.2017 KW - Femtosecond laser ablation KW - Laser-induced periodic surface structures (LIPSS) KW - Biomimetics KW - Fluid transport KW - Steel PY - 2017 AN - OPUS4-42354 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kirner, Sabrina V. A1 - Hermens, U. A1 - Winands, K. A1 - Mescheder, H. A1 - Florian, C. A1 - Solis, J. A1 - Siegel, J. A1 - Hischen, F. A1 - Baumgartner, W. A1 - Skoulas, E. A1 - Mimidis, A. A1 - Stratakis, E. A1 - Spaltmann, Dirk A1 - Krüger, Jörg A1 - Bonse, Jörn T1 - Bioinspired morphologies generated on steel surfaces by ultrashort laser pulse irradiation mimicking the fluid transport of bark bugs N2 - 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. T2 - E-MRS Spring Meeting 2017, Symposium K: Bioinspired and biointegrated materials as new frontiers nanomaterials VII CY - Strasbourg, France DA - 22.05.2017 KW - Femtosecond laser ablation KW - Laser-induced periodic surface structures (LIPSS) KW - Biomimetics KW - Fluid transport KW - Steel PY - 2017 AN - OPUS4-42331 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bonse, Jörn A1 - Hermens, U. A1 - Kirner, Sabrina V. A1 - Emonts, C. A1 - Comanns, P. A1 - Skoulas, E. A1 - Mimidis, A. A1 - Mescheder, H. A1 - Winands, K. A1 - Krüger, Jörg A1 - Stratakis, E. T1 - Mimicking lizard-like surface structures and their fluid transport upon ultrashort laser pulse irradiation of steel N2 - The wetting behavior of material surfaces can be controlled by surface structures. We functionalized case-hardened alloyed carbon steel to modify the wetting behavior using ultrashort laser pulses (fs- to ps-range). The laser processing was performed by scanning the laser beam across the surface of initially polished flat sample material. An experimental study of the laser processing parameters (peak fluence, scan velocity, line overlap) rendered an assignment of different regimes associated with characteristic surface morphologies (laser-induced periodic surface structures, grooves, micro cones, etc.) possible. Analyzing the surface using optical as well as scanning electron microscopy allowed the identification of morphologies providing the optimum similarity to the natural skin of non-moisture havesting lizards. For mimicking skin structures of moisture-harvesting lizards, additionally a two-step laser processing strategy was established for realizing hierarchical microstructures. In this approach, micrometer-scaled capillaries (step 1) were superimposed by a laser-generated regular array of small dimples (step 2). Optical focus variation imaging measurements finally revealed the three dimensional topography of the laser processed surfaces derived from lizard skin structures. The functionality of these surfaces was analyzed in view of wetting and directional fluid transport properties. The results suggest possible applications of the laser-structured surfaces. T2 - European Materials Research Society (EMRS) Spring Meeting 2017, Symposium K “Bioinspired and biointegrated materials as new frontiers nanomaterials VII” CY - Strasbourg, France DA - 22.05.2017 KW - Lizards KW - Laser processing KW - Steel KW - Fluid transport KW - Wetting PY - 2017 AN - OPUS4-40421 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -