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We put forward a co-axial pump(optical)-probe(X-rays) experimental concept and show performance of the optical component. A Bessel beam generator with a central 100 micrometers-diameter hole (on the optical axis) was fabricated using femtosecond (fs) laser structuring inside a silica plate. This flat-axicon optical element produces a needle-like axial intensity distribution which can be used for the optical pump pulse. The fs-X-ray free electron laser (X-FEL) beam of sub-1 micrometer diameter can be introduced through the central hole along the optical axis onto a target as a probe. Different realisations of optical pump are discussed. Such optical elements facilitate alignment of ultra-short fs-pulses in space and time and can be used in light-matter interaction experiments at extreme energy densities on the surface and in the volume of targets. Full advantage of ultra-short 10 fs X-FEL probe pulses with fs-pump(optical) opens an unexplored temporal dimension of phase transitions and the fastest laser-induced rates of material heating and quenching. A wider field of applications of fs-laser-enabled structuring of materials and design of specific optical elements for astrophotonics is presented.

A simple procedure is demonstrated for fabrication of waveplates which can be released from substrate by laser cutting. Oblique angle deposition, chemical etching and laser inscription steps were used for the final lift-off and release of micro-waveplates in HCl solution., Comment: 3 pages

The integration of a PDMS membrane within orthogonally placed PMMA microfluidic channels enables the pneumatic actuation of valves within bonded PMMA-PDMS-PMMA multilayer devices. Here, surface functionalization of PMMA substrates via acid catalyzed hydrolysis and air plasma corona treatment were investigated as possible techniques to permanently bond PMMA microfluidic channels to PDMS surfaces. FTIR and water contact angle analysis of functionalized PMMA substrates showed that air plasma corona treatment was most effective in inducing PMMA hydrophilicity. Subsequent fluidic tests showed that air plasma modified and bonded PMMA multilayer devices could withstand fluid pressure at an operational flow rate of 9 mircoliters/min. The pneumatic actuation of the embedded PDMS membrane was observed through optical microscopy and an electrical resistance based technique. PDMS membrane actuation occurred at pneumatic pressures of as low as 10kPa and complete valving occurred at 14kPa for 100 micrometers x 100 micrometers channel cross-sections., Comment: Submitted on behalf of EDA Publishing Association (http://irevues.inist.fr/handle/2042/16838)

We present a thermal activated solvent bonding technique for the formation of embedded microstrucutres in polymer. It is based on the temperature dependent solubility of polymer in a liquid that is not a solvent at room temperature. With thermal activation, the liquid is transformed into a solvent of the polymer, creating a bonding capability through segmental or chain interdiffusion at the bonding interface. The technique has advantages over the more commonly used thermal bonding due to its much lower operation temperature (30 degrees C lower than the material's Tg), lower load, as well as shorter time. Lap shear test indicated bonding shear strength of up to 2.9 MPa. Leak test based on the bubble emission technique showed that the bonded microfluidic device can withstand at least 6 bars (87 psi) of internal pressure (gauge) in the microchannel. This technique can be applied to other systems of polymer and solvent., Comment: Submitted on behalf of EDA Publishing Association (http://irevues.inist.fr/EDA-Publishing)

We report on the development of some process capabilities for a polymer-based, multi-layer microelectrofluidic platform, namely: the hot embossing process, metallization on polymer and polymer bonding. Hot embossing experiments were conducted to look at the effects of load applied, embossing temperature and embossing time on the fidelity of line arrays representing micro channels. The results revealed that the embossing temperature is a more sensitive parameter than the others due to its large effect on the polymer material's viscoelastic properties. Dynamic mechanical analysis (DMA) on polymethyl methacrylate (PMMA) revealed a steep glass transition over a 20 oC range, with the material losing more than 95 % of its storage modulus. The data explained the hot embossing results which showed large change in the embossed channel dimensions when the temperature is within the glass transition range. It was demonstrated that the micro-printing of silver epoxy is a possible low-cost technique in the mass production of disposable lab chips. An interconnecting network of electrical traces was fabricated in the form of a four-layer PMMA-based device. A four PMMA layer device with interconnecting microfluidic channels was also fabricated and tested., Comment: Submitted on behalf of TIMA Editions (http://irevues.inist.fr/tima-editions)