Constantly increasing demand of renewable and nonpolluting energy production methods has made solar cells one of today's hottest research areas. Developing more cost-effective fabrication methods that enable production of extremely non-refl ecting surfaces is one of the key issues in solar cell research. [ 1 , 2 ] Many other applications, such as miniaturized chemical analysis systems, would also benefi t greatly from low-cost surfaces with low and uniform refl ectivity. [ 3 ] Typically, suppression of Fresnel refl ection has been achieved by antirefl ective coatings, but they suppress refl ection effi ciently only in a narrow wavelength range. Suppression of refl ection over a broad spectral range can be achieved by using nanotextured surfaces that form a graded transition of the refractive index from air to the substrate. [ 1 , 2 , 4-12 ] Here, we present a scalable, high-throughput fabrication method for such non-refl ecting nanostructured surfaces. Original nanostructures are etched on a silicon wafer and replication methods enable their transfer into polymeric materials. Previously, transfer of non-refl ecting structures into polymeric materials has not received enough attention. The fabrication starts with a maskless plasma-etching step, which forms nanosized spikes on a silicon substrate. Using the Taguchi method, [ 13 ] we show that the sidewall angles and heights of the nanospikes are controlled by the plasma-etching parameters. A silicon surface with pyramidshaped nanospikes serves as a template in the fabrication of an elastomeric stamp, which enables replication of the original nanospike pattern into polymeric materials. Denser nanospike arrays with steeper sidewalls suppress the refl ection of light most effi ciently, but they are not well-suited for replication. The refl ection measurements show that all implemented nanostructured surfaces greatly reduce the refl ection of light over a broad spectrum and that the size of the nanospikes contributes substantially to the antirefl ection properties. Our application for non-refl ecting surfaces is laser desorption ionization mass spectrometry (LDI-MS), which is a common technique in chemical analysis. [ 3 , 14 ] As a consequence of suppressed light refl ection, lower laser fl uence is enough to desorb and ionize the analytes from a nanostructured surface. We also make the surfaces self-cleaning by coating them with a low surface energy fl uoropolymer. High-throughput fabrication of low-cost self-cleaning surfaces, which suppress the refl ection of light over a wide spectral range, is expected to have applications ranging from chemical analysis of drugs and biomolecules to photovoltaics.

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We hypothesized that when compared with conventional two-dimensional (2D) cultures, substrates containing 3D micropillars would allow cells to grow at levels, activating their cytoskeleton to promote osteogenesis. Fibroblasts, osteoblast-like cells, and mesenchymal stem cells (MSCs) were studied. Planar substrates were compared with 200-nm-, 5-μm-, and 20-μm-high pillars of Ormocomp®, Si, diamond-like carbon, or TiO(2). Scanning electron microscopy and staining of actin cytoskeleton showed 7.5-h adhesion to pillar edges and 5-day stretching between adhesion contacts > 100-μm distances of fibroblast and MSC in 3D networks, whereas SaOS-2 cells adhered flatly and individually on horizontal and vertical surfaces. ERK and ROCK immunostaining at 14 and 21 days confirmed activation of the cytoskeleton. In contrast to expectations, success to induce osteogenesis was dominated by the cytocompatibility of the substrate over the 3D structure. This was shown using early alkaline phosphatase, intermediate osteopontin, and late mineralization markers, together with bone nodule formation, which were seen in planar substrates and low-profile TiO(2) pillars, but were poor in the 20-μm landscape. The lack of intercellular contacts seems to halt the osteogenesis-promoting effects of cytoskeletal organization and tension described earlier.

Monolithically integrated, polymer (SU-8) microchips comprising an electrophoretic separation unit, a sheath flow interface and an ESI emitter were developed to improve the speed and throughput of proteomics analyses. Validation of the microchip method was performed based on peptide mass fingerprinting and single peptide sequencing of selected protein standards. Rapid, yet reliable identification of four biologically important proteins (cytochrome C, β-lactoglobulin, ovalbumin and BSA) confirmed the applicability of the SU-8 microchips to ambitious proteomic applications and allowed their use in the analysis of human muscle cell lysates. The characteristic tryptic peptides were easily separated with plate numbers approaching 10(6), and with peak widths at half height as low as 0.6 s. The on-chip sheath flow interface was also exploited to the introduction of an internal mass calibrant along with the sheath liquid which enabled accurate mass measurements by high-resolution Q-TOF MS. Additionally, peptide structural characterization and protein identification based on MS/MS fragmentation data of a single tryptic peptide was obtained using an ion trap instrument. Protein sequence coverages exceeding 50% were routinely obtained without any pretreatment of the proteolytic samples and a typical total analysis time from sampling to detection was well below ten minutes. In conclusion, monolithically integrated, dead-volume-free, SU-8 microchips proved to be a promising platform for fast and reliable analysis of complex proteomic samples. Good analytical performance of the microchips was shown by performing both peptide mass fingerprinting of complex cell lysates and protein identification based on single peptide sequencing.