Overview and details of the sessions of this conference. Please select a date or location to show only sessions at that day or location. Please select a single session for detailed view (with abstracts and downloads if available).
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Session Chair: Dr. Thomas Stichel, Bayerisches Laserzentrum GmbH (blz), Germany
Location:Room 3 ICM
1:30pm - 1:45pm
Micromachining of transparent biocompatible polymers used as vision implants with bursts of femtosecond laser pulses
Simas Butkus, Evaldas Kažukauskas, Vytautas Jukna, Domas Paipulas, Valdas Sirutkaitis
Laser Research Center, Vilnius University, Lithuania
Biocompatible plastics are used for many different purposes (catheters, artificial heart components, dentistry products, etc.). An important field biocompatible polymers is the production of vision implants known as intraocular lenses (IOLs) or custom-shape contact lenses, which are typically produced by means of milling, turning or lathe cutting and subsequent polishing. The multiple-step process is expensive and may take up days to produce the final part which is individually customized to meet the patient's needs.
In this work we propose a novel, all-laser-based method for the production of custom-shape lenses which may work as eye-implants. The shape of the lens from the plastic material (Contamac CONTAFLEX 26% UV-IOL) is produced by means of femtosecond ablation in a few minutes and afterwards it is polished by utilizing burst of femtosecond pulses in the GHz regime. In this way, transparent optical-quality lenses are produced in under 5 minutes of laser fabrication.
1:45pm - 2:00pm
Solvent evaporation and annealing of solution-processed organic materials by laser irradiation on flexible substrates
Frederik Kiel1, Cemal Esen1, Andreas Ostendorf1, Volker Wirth2
The market for flexible, printed and organic electronics is rapidly growing. The production is often based on wet-chemical processes and the residual solvent needs to be removed. Conventional methods for solvent evaporation or annealing of functional layers in roll-to-roll (R2R-) processing are circulating-air- or infrared-dryers. These methods require a relatively large drying section and entail a long exposure time at elevated temperatures for the flexible substrates. By utilizing a diode-laser as heating source the installation space and especially the exposure time at elevated temperatures could be minimized.
A LIMO line laser system (450 W, 980 nm) was used to investigate the substitution of conventional drying/ annealing methods on a lab scale (laser line FWHM: 12,22x0,06 mm²) for organic photovoltaic cells resulting in comparable power conversion efficiencies to conventional methods at processing speeds of 1m/min.
These results are expected to be transferred from the lab scale to a R2R-system.
2:00pm - 2:15pm
Processing and wetting behavior of microstructured polymer foils
Felix Bouchard1, Marcos Soldera2, Robert Baumann1, Andrés-Fabián Lasagni1,3
1Technische Universität Dresden, Institut für Fertigungstechnik, George-Baehr-Str. 3c, 01069 Dresden, Germany; 2PROBIEN-CONICET, Dto. de Electrotecnia, Universidad Nacional del Comahue, Buenos Aires 1400, Neuquén 8300, Argentina; 3Fraunhofer-Institut für Werkstoff- und Strahltechnik (IWS), Winterbergstraße 28, 01277 Dresden, Germany
The demand for surface functionalized plastics is constantly rising. Therefore, industrial-scalable methods capable to provide surfaces with new functions are necessary. In this study, we demonstrate a strategy to apply hierarchical microstructures to transparent polyethlyene therepthalate (PET) foils by plate to plate hot embossing. To that end, a stainless steel stamp was patterned using two laser based processes, namely Direct Laser Writing (DLW) and Direct Laser Interference Patterning (DLIP). Several single scale and multi scale structures with feature sizes in the range 3 µm up to 50 µm and depths between 0.1 µm and 10 µm were processed on the metal master and transfered to the PET surface. The topography characterization by confocal microscopy and scanning electron microscopy revealed a satisfactory replication of the micostructures from the stamp to the polymer, even for the smallest features with lateral sizes of ~100 nm. The patterned surfaces showed an increased hydrophobic behavior characterized by static water contact angles up to 105°.
2:15pm - 2:30pm
Femtosecond laser-assisted mould fabrication for metal casting at the micro-scale
Enrico Casamenti1, Luciano Borasi2, Adeline Durand2, Samuel Rey1, Raphaël Charvet2, Cyril Dénéreaz2, Andreas Mortensen2, Yves Bellouard1
1Galatea Laboratory, École Polytechnique Fédérale de Lausanne (EPFL), Switzerland; 2Laboratory of Mechanical Metallurgy (LMM), École Polytechnique Fédérale de Lausanne (EPFL), Switzerland
Existing technologies for the production of metallic 3D micro-components are, in their current state, either too slow to be economically viable or produce porous and imperfect metal structures. Here we overcome those barriers by bringing metal casting to the realm of microfabrication. We present a process that enables the production of freeform, dense, 3D metal architectures at speeds well above alternative approaches for metal 3D printing at the same resolution. Using femtosecond laser micro-machining combined with chemical etching, arbitrarily shaped 3D-cavities are carved out of fused quartz substrates and subsequently pressure-infiltrated with high melting point metals, such as pure silver, copper and gold and their alloys. The resulting glass/metal combinations contain interconnected dense metal 3D structures that are shaped freely with micrometric resolution to enable new types of micro-devices and composite structures.