The survival, proliferation, and differentiation of freshly isolated and cultured cells were studied after absorbing film-assisted laser-induced forward transfer. Rat Schwann and astroglial cells and pig lens epithelial cells were used for transfer and the cells were cultured for 2 weeks after laser-pulsed transfer. All three cell types survived, proliferated, and differentiated under cell culture conditions and regained their original phenotype a few days after cell transfer. Time resolution studies have shown that the time required to accelerate the jets and droplets containing the cells was less than 1 micros and that the estimated minimum average acceleration of those ejected cells that reached a constant velocity was approximately 10(7) x g. This suggests that the majority of studied cells tolerated the extremely high acceleration at the beginning of the ejection and the deceleration during impact on the acceptor plate without significant damage to the original phenotype. These results suggest that the absorbing film-assisted laser-induced forward transfer technique appears to be suitable for several potential applications in tissue engineering and the biomedical tissue repair technologies.

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We present an investigation on absorbing film assisted laser induced forward transfer (AFA-LIFT) of fungus (Trichoderma) conidia. A KrF excimer laser beam [λ=248nm,FWHM=30ns (FWHM, full width at half maximum)] was directed through a quartz plate and focused onto its silver coated surface where conidia of the Trichoderma strain were uniformly spread. The laser fluence was varied in the range of 0–2600mJ∕cm2 and each laser pulse transferred a pixel of target material. The average irradiated area was 8×10−2mm2. After the transfer procedure, the yeast extract medium covered glass slide and the transferred conidia patterns were incubated for 20 h and then observed using an optical microscope. The transferred conidia pixels were germinated and the areas of the culture medium surfaces covered by the pixels were evaluated as a function of laser fluence. As the laser fluence was increased from 0 to 355mJ∕cm2 the transferred and germinated pixel area increased from 0 to 0.25mm2. Further increase in fluence resulted in a drastic decrease down to an approximately constant value of 0.06mm2. The yield of successful transfer by AFA-LIFT and germination was as much as 75% at 355mJ∕cm2. The results prove that AFA-LIFT can successfully be applied for the controlled transfer of biological objects.

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The machining process of transparent materials using the laser induced backside wet etching (LIBWE) procedure was studied. In the course of this, experimental investigations and numerical calculations were carried out. Fused silica plates were irradiated by an ArF excimer laser, using a naphthalene–methyl methacrylate solution as an absorbing liquid (concentration 0.85 mol dm−3, absorption coefficient at 193 nm 52 200 cm−1). The etch rate dependence on the applied laser fluence (varied from 110 to 860 mJ cm−2) was derived from the etch depths, measured using an atomic force microscope (AFM). The etch rate was found to be 4.7–49.5 nm/pulse, depending on the laser fluence. The surface morphology of the etched edges was also investigated by AFM. A fast photographic arrangement was used for time resolved observation of bubble development in the liquid absorbent, which is an important phenomenon of LIBWE. The internal pressure of the expanding bubbles was calculated using recorded snapshots. It was found to be 22–120 MPa 17.2 ns after the excimer pulse peak. The one-dimensional heat flow equation, including the melting of the treated fused silica layer and the vaporization of the absorbing solution, was solved using the finite difference method. The surface temperature of the fused silica was found to be a maximal 17.2 ns after the excimer pulse peak. Based on our results, we present a possible interpretation of the LIBWE procedure of fused silica.

Photoreactive composite thin layers with tunable wetting properties from superhydrophilic to superhydrophobic nature were prepared. To achieve extreme wetting properties, the adequate surface roughness is a crucial factor, which was achieved by the incorporation of plasmonic Ag-TiO 2 particles, as polymer filler, into the smooth polymer film with adjusted hydrophilicity. The initial copolymer films were synthesized from hydrophilic 2-hydroxyethyl-acrylate (HEA) and hydrophobic perfluorodecyl-acrylate (PFDAc) monomers. In the case of hydrophobic PFDAc, the photocatalyst-roughened thin films displayed superhydrophobic behavior (γ s tot~ 2.3±1.7 mJ/m 2 , Θ > 150°), while the roughened hydrophilic pHEA layers possessed superhydrophilicity (γ s tot~ 72.1±0.2 mJ/m 2 , Θ~ 0°). The photoactivity of the composites was presented both in solid/ gas (S/G) and solid/ liquid (S/L) interfaces. According to the light-emitting diode (LED) light photodegradation tests on ethanol (EtOH) as volatile organic compound (VOC) model-molecules at the S/L interface, the superhydrophobic hybrid layer was photooxidized 88.3% of the initial EtOH (0.36 mM). At S/L interface the photocatalytic efficiency was depended on the polarity of the model pollutant molecules: the photooxidation of hydrophobic SUDAN IV (c 0 = 0.25 mg/mL) dye reached 80%, while in the case of the hydrophilic Methylene Blue dye (c 0 = 0.002 mg/mL) it was only 17.3% after 90 min blue LED light (λ = 405 nm) illumination.

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