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Rapid manufacturing of functionalized polymers enable a cost-efficient method for many applications in the biological, and medical sector. Laser structuring techniques differ for fast fabrication processes of thermoplastics. Here we report on direct UV laser ablation of polystyrene and polydimethylsiloxane to control wettability and bio-compatibility. For this purpose contact angle measurements and L929 cell growth experiments were performed as function of laser and process parameters. This work also describes the potential of laser-assisted hot embossing which has been introduced to replicate pre-fabricated micro- and nano-sized structures onto polymers proving it to be a cost-efficient and flexible method for surface functionalization. Therefore, pre-fabricated laser-induced periodic surface structures have been manufactured as mould inserts using ultrafast laser radiation near the ablation threshold. These mould inserts can also be made of nickel, silicon or glass proving laser-assisted hot embossing to be a versatile tool for the functionalization of thermoplastics and meet the requirements for modern manufacturing with regard to quality and production flexibility.

Laser moulding is a new polymer moulding process developed and enhanced for the fabrication of micro- and nanostructured components at the Karlsruhe Institute of Technology. This report describes the potential offering by laser moulding. Besides known polymer moulding techniques like injection moulding or hot embossing, laser moulding can also achieve significant advantages compared to the existing technologies. Assisted by a high power diode laser radiation (wavelength 940 nm) a micro- or nanostructure of a mould will be transferred to a thermoplastic polymer product. With regard to the efficiency of production, micro- and nanostructures should be fast, competitive and flexibly transferred to a thermoplastic polymer surface. For this purpose the moulding by laser radiation provides ideal conditions, advantages and a variety of applications. These conditions, advantages and applications were tested by using different micro- or nanostructured mould inserts made of silicon, glass or nickel as well as different thermoplastic polymers which were used for replication such as, polymethylmethacrylate, polystyrene, cyclo-olefin copolymers and polyether ketones. The new technical approach and his first results will be described in this report.

Recently microfluidic devices have emerged as a viable technology for the miniaturization of high throughput tools for analytical tasks related to structural biology such as screening of crystallization conditions and structural analysis. This work reports the manufacture of microfluidic chips in transparent thermoplastic polymers [poly(methylmethacrylate) (PMMA), and cyclic olefin copolymer (COC)] using two complementary technologies, injection moulding for the fabrication of the fluidic level and laser transmission welding for the sealing of the cover. A steel mould insert was produced by laser micro caving using a solid state laser radiation source (Nd:YAG, wavelength 1,064 nm). Fluidic chips of ~670 μm thickness comprising channels of 50 μm depth and width down to 50 μm were injection moulded in PMMA and COC. Joining of transparent thin cover film to the micro-injected fluidic level was performed by laser transmission welding using high power diode laser radiation (wavelength 940 nm) and an intermediate thin absorbing layer with a thickness of about several nanometers.

SnOx electrode thin films for lithium ion batteries were deposited by reactive and non-reactive rf magnetron sputtering of a SnO2 target in an argon–oxygen atmosphere. Amorphous and nano-crystalline SnOx films could be synthesized, with regard to the O2:Ar volume ratio in the sputter gas which was adjusted to 0, 3.5 or 10%. Laser micro-structuring using a KrF excimer laser operating at a wavelength of λ = 248 nm was applied to create free-standing microstructures. Thus, the active surface of the anode material was significantly increased. Furthermore, it was expected that the large volume changes during electrochemical cycling of SnOx could be better compensated by a microstructured surface. The laser parameters were optimized in a way which leads to structures without any defects and little debris. Depending on the laser fluence and pulse number, free-standing conical structures could be formed with a horizontal spacing of

The rapid fabrication of microcomponents made from polymers or composites will be presented. The whole fabrication process is divided into three main steps: first, direct patterning of polymers with excimer laser radiation enables the fabrication of first prototypes. Second, laser assisted micromachining using Nd:YAG or KrF-Excimer laser radiation allows a rapid manufacturing of microstructured mold inserts made of steel or polymer. Third, the application of UV-light-induced reaction injection molding (UV-RIM, photomolding) process using reactive monomer/polymer resins gives the access to the replication of the previously fabricated mold insert. For mold insert fabrication, the development of different process strategies is in progress in order to meet the best fit for three dimensional shapes (e.g., steep walls or slowly inclined walls). The development of mold inserts made of polymers is performed via UV laser ablation. This is a new promising method for the rapid manufacturing of microcomponents.

For the last years different “rapid”-technologies like Rapid Prototyping, Rapid Manufacturing or Rapid Tooling have been developed in the macro world for a fast prototype or molding tool generation in case of e.g. form visualisation or small scale production. Commercially available equipment allows smallest structural details of at least 100 μm and a position accuracy of 25 μm. Due to the poor achievable precision of the mentioned systems in comparison to the necessities in MST only a few attempts for the realisation of “micro-rapid” technologies have been investigated. In this work an approach which combines Rapid Tooling (mold insert fabrication via laser micromaching) with Rapid Prototyping (replication via light induced reaction injection molding) will be introduced and different examples for application e.g. in microfluidics will be given.