Laser Application of Polymers

Abstract

Laser ablation of polymers has been studied with designed materials to evaluate the mechanism of ablation and the role of photochemically active groups on the ablation process, and to test possible applications of laser ablation and designed polymers. The incorporation of photochemically active groups lowers the threshold of ablation and allows high-quality structuring without contamination and modification of the remaining surface. The decomposition of the active chromophore takes place during the excitation pulse of the laser and gaseous products are ejected with supersonic velocity. Time-of-flight mass spectrometry reveals that a metastable species is among the products, suggesting that excited electronic states are involved in the ablation process. Experiments with a reference material, i.e., polyimide, for which a photothermal ablation mechanism has been suggested, exhibited pronounced differences. These results strongly suggest that, in case of designed polymers which contain photochemically active groups, a photochemical part in the ablation mechanism cannot be neglected. Various potential applications for laser ablation and the special photopolymers were evaluated and it became clear that the potential of laser ablation and specially designed material is in the field of microstructuring. Laser ablation can be used to fabricate three-dimensional elements, e.g., microoptical elements.Keywords Laser ablation · Ablation mechanism · Photopolymers · Polyimide · Spectroscopy This was not always true, of course. For many years, the laser was viewed as "an answer in search of a question". That is, it was seen as an elegant device, but one with no real useful application outside of fundamental scientific research. In the last two to three decades however, numerous laser applications have moved from the laboratory to the industrial workplace or the commercial market. Lasers are unique energy sources characterized by their spectral purity, spatial and temporal coherence, and high average peak intensity. Each of these characteristics has led to applications that take advantage of these qualities: -Spatial coherence: e.g., remote sensing, range finding and many holographic techniques. -Spectral purity: e.g., atmospheric monitoring based on high-resolution spectroscopies. -and of course the many other applications in communication and storage, e.g., CDs.All of these high-tech applications have come to define everyday life in the late twentieth century. One property of lasers, however, that of high intensity, did not immediately lead to "delicate" applications but rather to those requiring "brute force". That is, the laser was used in applications for removing material or heating. The first realistic applications involved cutting, drilling, and welding, and the laser was little more advanced than a saw, a drill, or a torch. In a humorous vein A.L. Schawlow proposed and demonstrated the first "laser eraser" in 1965 [4], using the different absorptivities of paper and ink to remove the ink without damaging the und...

Laser Surface Texturing of Polymers for Biomedical Applications

“…This technique offers a great number of advantages; in particular, the most important is the possible modification of surface roughness and chemistry in one step avoiding the utilization of toxic substances. Laser surface texturing can modify polymeric surfaces at a macro-, micro-, and nano-size scale with a high spatial and temporal resolution [21]. Given the non-contact nature of the process, the contamination of the workpiece is easily avoided; this is a very important advantage for biomedical applications as the sterilization of the implants can be guaranteed.…”

“…More recently, some research works (using in vivo and in vitro tests) have been performed to elucidate this enhancement in the biological response of the laser-treated polymeric biomaterials; however, more studies are still needed to transfer this technique into the current clinical practice. With this work, we intend to complement reviews on laser patterning, mainly concentrated on laser ablation mechanisms (e.g., [21,[25][26][27]), and to provide the reader with a critical understanding on the next steps to advance in this field.…”

Laser-plasma extreme ultraviolet and soft X-ray sources based on a double stream gas puff target: interaction of the radiation pulses with matter

“…Appropriate modifications can be achieved by chemical [37], plasma [38], or radiation treatment. For the photo− −induced modification of polymers, excimer lamps or ex− cimer lasers are mainly used [39][40][41].…”

18 Coupling CE and microchip-based devices with mass spectrometry

“…350,351 Channels of various geometries and dimensions can be obtained using an appropriate mask. Many commercially available polymers can be photoablated, including polycarbonate, poly(methyl methacrylate) (PMMA), polystyrene, nitrocellulose, poly(ethylene terphtalate) (PET), and poly(tetrafluoroethylene) (Teflon).…”