Ingenieurwissenschaften und zugeordnete Tätigkeiten
Filtern
Erscheinungsjahr
Dokumenttyp
- Zeitschriftenartikel (35)
- Vortrag (20)
- Beitrag zu einem Tagungsband (8)
- Buchkapitel (4)
Schlagworte
- Laser-induced periodic surface structures (LIPSS) (15)
- Radiation protection (12)
- Femtosecond laser (11)
- Femtosecond laser ablation (9)
- Laser processing (8)
- Laser-induced X-ray emission (8)
- Surface functionalization (8)
- Laser ablation (7)
- Materialbearbeitung (7)
- Ultrakurze Laserpulse (6)
- Ultrashort laser pulses (6)
- Nanostructures (5)
- Röntgenstrahlung (5)
- Strahlenschutz (5)
- Laser-induced periodic surface structures, LIPSS (4)
- Ultrakurzpulslaser (4)
- Ultrashort laser material interaction (4)
- X-ray emission (4)
- Applications (3)
- Friction (3)
- Laser-induced periodic surface structures (3)
- Laser-induzierte Röntgenstrahlung (3)
- Oxidation (3)
- Secondary hazard (3)
- Steel (3)
- Titanium alloy (3)
- Ultrashort pulse laser processing (3)
- Ultrashort pulsed laser (3)
- Abschirmung (2)
- Auge (2)
- Biofilms (2)
- Cell adhesion (2)
- Femtosekundenlaser (2)
- Laser-induced x-ray emission (2)
- Laserschutz (2)
- Material processing (2)
- Medizinische Anwendung (2)
- Microstructures (2)
- Pacemaker (2)
- Röntgenemission (2)
- Titanium (2)
- Ultra-short pulse laser processing (2)
- Ultrakurze Laserimpulse (2)
- Wear (2)
- X-ray photoelectron spectroscopy (2)
- Zahn (2)
- Amorphization (1)
- Anodic oxidation (1)
- Anodization (1)
- Antibacterial surfaces (1)
- Application (1)
- Auger electron spectroscopy (1)
- Bacterial adhesion (1)
- Biofilm (1)
- Bioinspiration (1)
- Biologische Anwendungen (1)
- Biomedizin (1)
- Biomimetic surfaces (1)
- Bionic materials (1)
- Bone implant (1)
- Calcium phosphate coating (1)
- Carrier excitation (1)
- Conservation (1)
- Crystallization (1)
- Cultural heritage (1)
- Dentistry (1)
- Dielectrics (1)
- Double-pulse (1)
- Double-pulse experiments (1)
- Editorial (1)
- Electromagnetic scattering (1)
- European Materials Research Society (E-MRS) (1)
- Femtosecond (1)
- Femtosecond laser processing (1)
- Fluid transport (1)
- Glasfilter (1)
- Hard X-ray photoelectron spectroscopy (HAXPES) (1)
- Hierarchical micro-nanostructures (1)
- Industrial applications (1)
- Interferometer (1)
- Laser Machining (1)
- Laser Processing (1)
- Laser cleaning (1)
- Laser damage (1)
- Laser induced damage (1)
- Laser materials processing (1)
- Laser micromachining (1)
- Laser-Materialbearbeitung (1)
- Laser-induced fixation (1)
- Laser-induced nanostructures (1)
- Laser-induced periodic surface strcutures (LIPSS) (1)
- Laser-material interactions (1)
- Laser-modified surface (1)
- Lasermaterialbearbeitung (1)
- Lasermikrobearbeitung (1)
- Laserreinigung (1)
- Lasersicherheit (1)
- Lizard (1)
- Mach-Zehnder interferometer (1)
- Microbial adhesion tests (1)
- Microbial adhesions (1)
- Nanosecond Pulses (1)
- Nanostrcutures (1)
- Nd:YAG laser (1)
- Niobium (1)
- Oberflächenstrukturierung (1)
- Ophthalmology (1)
- Optical multimode fiber (1)
- Optics at surfaces (1)
- Photovoltaik (1)
- Polyethylene (1)
- Polymerfilter (1)
- Protection housing (1)
- Pulse Laser (1)
- Schutzbrille (1)
- Sekundärstrahlung (1)
- Silicon (1)
- Silk (1)
- Spectroscopic imaging ellipsometry (1)
- Spring Meeting 2016 (1)
- Surface morphology (1)
- Surface plasmon polariton (1)
- Surface superconductivity (1)
- Surface texture (1)
- Surface wetting (1)
- Technische Materialien (1)
- Thin films (1)
- Ti-6Al-4V alloy (1)
- Ti6Al4V alloys (1)
- Time-of-flight secondary ion mass spectrometry (ToF-SIMS) (1)
- Titanium nitride films (1)
- Tribology (1)
- Ultrafast optical techniques (1)
- Ultrafast phenomena (1)
- Ultrashort lasers (1)
- Ultrashort pulse laser (1)
- X-ray emission hazards (1)
- X-ray energies (1)
- X-ray spectrum (1)
- fused silica (1)
- laser damage (1)
- lossy materials (1)
- nanosecond laser (1)
- optical fiber (1)
- plasmon lifetime (1)
- surface plasmon polaritons (1)
Organisationseinheit der BAM
- 6 Materialchemie (45)
- 6.2 Material- und Oberflächentechnologien (45)
- 4 Material und Umwelt (2)
- 4.1 Biologische Materialschädigung und Referenzorganismen (2)
- 6.1 Oberflächen- und Dünnschichtanalyse (2)
- 6.7 Materialsynthese und Design (2)
- 5 Werkstofftechnik (1)
- 5.1 Mikrostruktur Design und Degradation (1)
- 6.6 Physik und chemische Analytik der Polymere (1)
- 9 Komponentensicherheit (1)
Paper des Monats
- ja (3)
Laser-induced periodic surface structures (LIPSS, ripples) are a universal phenomenon that can be observed on almost any material after the irradiation by linearly polarized laser beams, particularly when using ultrashort laser pulses with durations in the picosecond to femtosecond range. During the past few years significantly increasing research activities have been reported in the field of LIPSS, since their generation in a single-step process provides a simple way of nanostructuring and surface functionalization towards the control of optical, mechanical or chemical properties. In this contribution current applications of LIPSS are reviewed, including the colorization of technical surfaces, the control of surface wetting, the tailoring of surface colonization by bacterial biofilms, and the improvement of the tribological performance of nanostructured metal surfaces.
In this study, femtosecond laser-induced sub-micrometer structures are generated to modify polyethylene (PE) surface topographies. These surfaces were subjected to bacterial colonization studies with Escherichia coli and Staphylococcus aureus as test strains. The results reveal that the nanostructures do not influence S. aureus coverage, while the adhesion of E. coli is reduced.
Titanium and its alloys are known to allow the straightforward laser-based manufacturing of ordered surface nanostructures, so-called high spatial frequency laser-induced periodic surface structures (HSFL). These structures exhibit sub-100 nm spatial periods – far below the optical diffraction limit. The resulting surface functionalities are usually enabled by both, topographic and chemical alterations of the nanostructured surfaces. For exploring these effects, multi-method characterizations were performed here for HSFL processed on Ti–6Al–4V alloy upon irradiation with near-infrared ps-laser pulses (1030 nm, ≈1 ps pulse duration, 1–400 kHz) under different laser scan processing conditions, i.e., by systematically varying the pulse repetition frequency and the number of laser irradiation passes. The sample characterization involved morphological and topographical investigations by scanning electron microscopy (SEM), atomic force microscopy (AFM), tactile stylus profilometry, as well as near-surface chemical analyses hard X-ray photoelectron spectroscopy (HAXPES) and depth-profiling time-of-flight secondary ion mass spectrometry (ToF-SIMS). This provides a quantification of the laser ablation depth, the geometrical HSFL characteristics and enables new insights into the depth extent and the nature of the non-ablative laser-induced near-surface oxidation accompanying these nanostructures. This allows to answer the questions how the processing of HSFL can be industrially scaled up, and whether the latter is limited by heat-accumulation effects.
Surface nanostructures provide the possibility to create and tailor surface functionalities mainly via controlling their topography along with other chemical and physical material properties. One of the most appealing technologies for surface functionalization via micro- and nanostructuring is based on laser processing. This can be done either via direct contour-shaping of the irradiated material using a tightly focused laser beam or in a self-ordered way that allows employing larger laser beam diameters along with areal scanning to create a variety of laser-induced periodic surface structures (LIPSS). For the latter approach, particularly ultrashort pulsed lasers have recently pushed the borders across long-lasting limitations regarding the minimum achievable feature sizes and additionally boosted up the production times. This chapter reviews the plethora of recently investigated applications of LIPSS—for example, via imposing diffractive or plasmonic structural colors, the management of liquids and surface wetting properties, biomedical and bioinspired functionalities, beneficial effects in tribology for reducing friction and wear, the manipulation of optical scattering and absorption in photovoltaics, or the modification of magnetic or superconducting surface properties in other energy applications. The footprint of the LIPSS-based technology is explored in detail regarding the current state of industrialization, including an analysis of the market and associated LIPSS production costs.
In order to address the dynamics and physical mechanisms of LIPSS formation for three different classes of materials (metals, semiconductors, and dielectrics), two-color double-fs-pulse experiments were performed on Titanium, Silicon and Fused Silica. For that purpose a Mach–Zehnder interferometer generated polarization controlled (parallel or cross-polarized) double-pulse sequences at 400 nm and 800 nm wavelength, with inter-pulse delays up to a few picoseconds. Multiple of these two-color double-pulse sequences were collinearly focused by a spherical mirror to the sample surfaces. The fluence of each individual pulse (400 nm and 800 nm) was always kept below its respective ablation threshold and only the joint action of both pulses lead to the formation of LIPSS. Their resulting characteristics (periods, areas) were analyzed by scanning electron microscopy. The periods along with the LIPSS orientation allow a clear identification of the pulse which dominates the energy coupling to the material. For strong absorbing materials (Silicon, Titanium), a wavelength-dependent plasmonic mechanism can explain the delay-dependence of the LIPSS. In contrast, for dielectrics (Fused Silica) the first pulse always dominates the energy deposition and LIPSS orientation, supporting a non-plasmonic formation scenario. For all materials, these two-color experiments confirm the importance of the ultrafast energy deposition stage for LIPSS formation.
Given their unique properties, ultrashort laser pulses with durations in the femtosecond to picosecond range currently open new avenues in the field of laser materials processing, resulting in groundbreaking new applications based on laser-induced surface functionalization. This article reviews the usability of temporally distributed energy deposition via double-pulse irradiation in applications based on laser ablation. This includes simple new techniques for surface nanostructuring and improved sensitivities in spectroscopic material analyses.
The cleaning of aged silk fibers poses a common challenge in the conservation of textiles, since traditional cleaning techniques often yield unsatisfactory results or even harm objects. In this regard, cleaning objects with laser radiation is a promising addition to the range of available methods. Due to it being contactless, even brittle and touch-sensitive objects with disfiguring or harmful soiling could potentially be cleaned and therefore made accessible for research and presentation. Examples of treatment have sometimes shown spectacular results. Still there is some skepticism concerning the safety of this treatment for textile materials, which has been strengthened through previous 532 nm wavelength nanosecond laser cleaning studies on silk fibers. Taking these published results into account, the range of examined laser parameters has been extended in this study, from 532 nm nanosecond laser to 1064 nm nanosecond and even 800 nm femtosecond laser, reevaluating the effect of this treatment on the fibers. The physicochemical processes taking place on the silk fibers when cleaning with lasers are complex and still not fully understood. The aim of this project was therefore to bring more clarification about potential effects of those processes on the condition of silk samples treated with a set of different parameters for wavelength, pulse duration, energy density and number of pulses per spot. It also looks at the influence of the presence of soiling on the results. The analysis of potential effects was then carried out using statistical methods and advanced analytics. Scanning electron microscopy, Fourier-transform infrared spectroscopy and colorimetry technology provided the required insights to better assess the effects. Results show that laser cleaning of silk fibers, like most other conventional cleaning techniques, is not completely without risk, but knowing what the possible effects are helps making decisions on whether the benefits of the technique used justify these risks.