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Fekete Z.,Research Institute for Technical Physics and Materials Science MFA | Fekete Z.,Budapest University of Technology and Economics | Holczer E.G.,Research Institute for Technical Physics and Materials Science MFA | Holczer E.G.,Budapest University of Technology and Economics | And 3 more authors.
Procedia Engineering | Year: 2011

The present work is intended to describe the design aspects of microfluidic structures applicable to dilute and transport analyte solutions to the sensing areas of biosensors. The behaviours of different chaotic mixer structures were analyzed numerically and experimentally to determine their efficiency. The characterized microstructures were realised in poly(dimethylsiloxane) (PDMS) by micro-fabrication and integrated into real microfluidic transport systems. Biological analyte was applied to verify their practical performance. © 2011 Published by Elsevier Ltd.


Kozma P.,Research Institute for Technical Physics and Materials Science MFA | Kozma P.,University of Pannonia | Kozma D.,Hungarian Academy of Sciences | Nemeth A.,Research Institute for Technical Physics and Materials Science MFA | And 7 more authors.
Applied Surface Science | Year: 2011

In this study, we have reconstructed the statistical 3D structure of hundreds of nanometers thick surface immobilized flagellar filament protein layers in their native environment, in buffer solution. The protein deposition onto the surface activated Ta2O5 film was performed in a flow cell, and the immobilization process was followed by in situ spectroscopic ellipsometry. A multilayer optical model was developed, in that the protein layer was described by five effective medium sublayers. Applying this method, an in-depth analysis of the protein layer formation was performed. Based on the kinetics in the distribution of the surface mass density, the statistical properties of the filamentous film could be determined computationally as a function of the measurement time. It was also demonstrated that the 3D structure of the protein layer can be reconstructed based on the calculated in-depth mass density profile. The computational investigation revealed that the filaments can be classified into two individual groups in approximately equal ratio according to their orientation. In the first group the filaments are close to laying position, whereas in the second group they are in a standing position, resulting in a significantly denser sublayer close to the substrate than at a larger distance. © 2011 Elsevier B.V.


Nagy N.,Research Institute for Technical Physics and Materials Science MFA | Zolnai Z.,Research Institute for Technical Physics and Materials Science MFA | Deak A.,Research Institute for Technical Physics and Materials Science MFA | Deak A.,Ludwig Maximilians University of Munich | And 3 more authors.
Journal of Nanoscience and Nanotechnology | Year: 2012

Various nanostructures were fabricated by ion irradiation on large area (100) Si surfaces covered by colloidal Langmuir-Blodgett films as nanolithographic masks. The ordered structure of the Langmuir- Blodgett monolayer composed from spherical Stöber silica particles of 200 nm and 450 nm diameter offer the possibility to form local surface swelling patterns during the ion bombardment step. Utilizing the dependence of the surface morphology on the irradiation parameters the tunability of nanostructuring was studied for 40 keV Ar+ and 500 keV Xe2+ ions. We show that the periodicity of the resulted surface pattern is determined by the size of the masking particles, while the height of nanostructures can be tuned by the ion fluence. The quality of projection of the nanomask contours to the substrate-the contrast of masking-can be set by choosing appropriate ion energy, thereby determining the curvature of the surface pattern. Moreover, deformation of the nanomask due to ion-nanoparticle interactions should be taken into account since these effects can be also utilized for tailoring various structures. The silica masking layers before and after ion irradiation and the resulting Si surface patterns were investigated by field emission scanning electron microscopy and atomic force microscopy analysis. Copyright © 2012 American Scientific Publishers.


Fekete Z.,Research Institute for Technical Physics and Materials Science MFA | Fekete Z.,Budapest University of Technology and Economics | Nagy P.,Research Institute for Technical Physics and Materials Science MFA | Nagy P.,Budapest University of Technology and Economics | And 3 more authors.
Procedia Engineering | Year: 2011

When aiming a complete microfluidic analysis system for human blood tests the blood plasma separation should be preferably also integrated in the device. The sensitivity of the analysis is significantly affected by the sample quality, so in this work the efficiency of the Zweifach-Fung effect based microfluidic separation systems was characterized. The microstructures were fabricated by simple replication in polydimethylsilixane applying SU-8 photoresist master beside extensive variation of the geometric parameters. © 2011 Published by Elsevier Ltd.


Detrich A.,Budapest University of Technology and Economics | Hild E.,Budapest University of Technology and Economics | Nagy N.,Research Institute for Technical Physics and Materials Science MFA | Volentiru E.,Budapest University of Technology and Economics | Horvolgyi Z.,Budapest University of Technology and Economics
Thin Solid Films | Year: 2012

Optical properties and in-depth structure of double-layer coatings on glass substrates were investigated. One of the layers was prepared by dip coating either from silica or titania sol, the other layer was made from ca. 130 nm Stöber silica particles by the Langmuir-Blodgett (LB) technique. Two different types of combined coatings were prepared: (1) nanoparticulate LB films coated with sol-gel (SG) films and (2) nanoparticulate LB films drawn onto SG films. Scanning electron microscopy and optical methods, i.e. UV-vis spectroscopy and scanning angle reflectometry were applied for analyzing the structure and thickness of coatings. These measurements revealed that the precursor sols could not penetrate into the particulate LB film completely in case of coating type (1). For coating type (2) very little overlap between the SG and LB layers was found resulting in significant improvement of light transmittance of combined coatings compared to single SG films. To show some possible advantages of the combination of these techniques additional studies were carried out. Surface morphology of combined coatings (1) was studied by atomic force microscopy. Surfaces with different roughness were developed depending on the thickness of the sol-gel film (titania: ca. 70 nm; silica: ca. 210 nm). The adhesive peel off test revealed improved mechanical stability of combined coatings (2), in comparison to LB films which makes them good candidates for further applications. © 2011 Elsevier B.V. All rights reserved.


Misjak F.,Research Institute for Technical Physics and Materials Science MFA | Barna P.B.,Research Institute for Technical Physics and Materials Science MFA | Radnoczi G.,Research Institute for Technical Physics and Materials Science MFA
Thin Solid Films | Year: 2010

Eutectic composition Cu-Ag alloy thin films were prepared by co-deposition at room temperature onto oxidized Si substrates by thermal evaporation. Morphological development, structure and phase state of the films were investigated by transmission electron microscopy. The films possess fibre morphology 10-30 nm in diameter and strong <111> texture is present. The fibres are nanocrystalline composed of 2-3 nm size zones of Cu and Ag rich solid solution phases and a model for morphological development and phase separation is described. In the early stages of growth phase separation occurs by nucleation in melted islands and a eutectic of randomly oriented crystallites forms. In later stages of growth the phase separation takes place by spinodal decomposition. It results in a strain stabilized unique morphology corresponding to an intermediate stage of phase separation. © 2010 Elsevier B.V. All rights reserved.


Baji Z.,Research Institute for Technical Physics and Materials Science MFA | Labadi Z.,Research Institute for Technical Physics and Materials Science MFA | Horvath Z.E.,Research Institute for Technical Physics and Materials Science MFA | Fried M.,Research Institute for Technical Physics and Materials Science MFA | And 2 more authors.
Journal of Thermal Analysis and Calorimetry | Year: 2011

This study on ALD grown ZnO layers is aimed at the systematic study of the effect of incorporation of different Al contents on the properties of the layers. An alternate precursor pulse method was used for layer deposition. Optimal doping was achieved at 210 °C at 2 at% Al content. A relationship between crystalline morphology versus temperature and aluminium incorporation was established. © 2011 Akadémiai Kiadó, Budapest, Hungary.


Baji Z.,Research Institute for Technical Physics and Materials Science MFA | Labadi Z.,Research Institute for Technical Physics and Materials Science MFA | Horvath Z.E.,Research Institute for Technical Physics and Materials Science MFA | Barsony I.,Research Institute for Technical Physics and Materials Science MFA
Thin Solid Films | Year: 2012

The aim of this work is to study the effects of deposition temperature and aluminium incorporation on the crystalline properties, orientation and grain size of atomic layer deposited ZnO layers. X-ray diffraction analysis revealed a change in the dominant crystallite orientation with increasing substrate temperature. The most perfect crystal structure and largest grain size was found at 2 at.% aluminium content. Accumulation of compressive strain developed a monotonous increase with the growth temperature. Electric resistivity showed no anisotropy despite the change in the orientation, therefore the dominant conduction mechanism is not grain boundary related. © 2011 Elsevier B.V. All rights reserved.


PubMed | Research Institute for Technical Physics and Materials Science MFA
Type: Journal Article | Journal: Journal of nanoscience and nanotechnology | Year: 2012

Various nanostructures were fabricated by ion irradiation on large area (100) Si surfaces covered by colloidal Langmuir-Blodgett films as nanolithographic masks. The ordered structure of the Langmuir-Blodgett monolayer composed from spherical Stber silica particles of 200 nm and 450 nm diameter offer the possibility to form local surface swelling patterns during the ion bombardment step. Utilizing the dependence of the surface morphology on the irradiation parameters the tunability of nanostructuring was studied for 40 keV Ar+ and 500 keV Xe2+ ions. We show that the periodicity of the resulted surface pattern is determined by the size of the masking particles, while the height of nanostructures can be tuned by the ion fluence. The quality of projection of the nanomask contours to the substrate-the contrast of masking-can be set by choosing appropriate ion energy, thereby determining the curvature of the surface pattern. Moreover, deformation of the nanomask due to ion-nanoparticle interactions should be taken into account since these effects can be also utilized for tailoring various structures. The silica masking layers before and after ion irradiation and the resulting Si surface patterns were investigated by field emission scanning electron microscopy and atomic force microscopy analysis.

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