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Výroba a charakterizace pokročilých mikrofluidních čipů
Vejrosta, Jakub ; Novotný,, Jakub (oponent) ; Plichta, Tomáš (vedoucí práce)
Tato diplomová práce se zabývá návrhem, výrobou a ověřením funkce mikrofluidních čipů, pomocí kterých je možné třídit částice za využití povrchové akustické a stojaté povrchové akustické vlny. Třídící funkce tohoto čipu je založena na piezoelektrických vlastnostech substrátu. Z tohoto důvodu byl jako substrát vybrán niobičnan lithný. Akustické vlny jsou generovány pomocí interdigitálních převodníků umístěných přímo na povrchu substrátu, které byly vyrobeny technologií napařování kovových vrstev, optickou litografií a reaktivního leptání iontovým svazkem. Samotné mikrofluidní kanály byly odlity z biokompatibilního polymeru polydimethylsiloxanu a následně nalepeny na podložní substrát s již připravenými interdigitálními převodníky. Správnost výroby a kompletace optimalizovaných mikrofluidních čipů byla následně ověřena experimentálně, kdy byly tříděny částice polystyrenu různých průměrů. Další aplikací těchto čipů byla příprava orientovaných struktur bakterií Cupriavidus necator H16 za pomoci povrchové akustické vlny.
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Nanoscaled polypyrrole for sensing gaseous analytes and volatile organic compounds
Šetka, Milena ; Dian,, Juraj (oponent) ; Mandayo, Gemma García (oponent) ; Drbohlavová, Jana (vedoucí práce)
Polypyrrole (PPy) is a hetero-cyclic conductive polymer (CPs) with chemical structure based on the existence of conjugated electrons between alternating single and double bond system. This polymer has occupied the attention of many scientists from different research disciplines due to its outstanding properties such as good electrical conductivity, relatively high environmental stability, and facile and diversified synthesis methods. The aim of this research was to study the sensing behavior of PPy. Therefore, the gas sensing performances of PPy nanostructures were verified to ‘gas molecules of high importance’ including acetone, ammonia, ethanol, ethylene and toluene. In this work, PPy in the form of nanorods (NRs) and nanoparticles (NPs) was prepared using electrochemical and chemical synthesis approaches, respectively. Additionally, the modified PPy structures were developed by functionalization of PPy NPs with catalytic particles of gold (Au), silver (Ag) and cadmium-telluride (CdTe). Many complementary analytical techniques (microscopic and spectroscopic) were used for the investigation of morphology, composition and structure of the synthesized materials. Moreover, spectroscopy techniques such as Raman and X-Ray Photoelectron Spectroscopy (XPS) were employed for in-situ gas sensing tests, which confirmed the potential of PPy NRs and PPy NPs to be used as gas sensitive materials. In order to developed the gas sensor device, the PPy based materials were integrated into chemo-resistive and Love mode surface acoustic wave (L-SAW) transducing platforms. The gas sensing test of chemo-resistive sensors based on PPy NRs revealed negligible response to nitrogen dioxide and ammonia due to complicate architecture of those sensors. The measuring of response of non-modified and modified PPy NPs chemo-resistive sensors was complex due to their extremely high resistance in G range. However, multi-guiding L-SAW sensors based on bare PPy NPs and modified with Au NPs and Ag NPs, and CdTe quantum dots (QDs) manifested the response to low concentration of all tested target gas molecules including ammonia, acetone, ethanol, ethyleen and toluene at room temperature (RT). Generally, the L-SAW sensors with modified sensing layers established enhanced sensing performances over non-modified sensors. The performance of the L-SAW sensor primarily depends on the operating frequency and the choose of sensitive layer in the active region of the sensor. Thus, among the tested sensing layers for the target gases, modified PPy layer with Ag NPs and/or Au NPs can be selected as the best option for the detection of acetone. The developed PPy based L-SAW sensors are simple and cost effective devices with improved sensing properties such as high sensitivity and low limit of detection (LOD) which make them potential candidates in future systems for air quality control, food quality control or disease diagnosis via exhaled breath.
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Filtr s akustickou povrchovou vlnou
Tichý, Jakub ; Dědková, Jarmila (oponent) ; Raida, Zbyněk (vedoucí práce)
Teoretická část této práce se zabývá principy a vlastnostmi filtru s akustickou povrchovou vlnou. Je zde vysvětlen princip magnetostrikce a piezoelektrického jevu, který filtr využívá. V praktické části jsou v programu Comsol Multiphysics vytvořeny tři jednoduché modely SAW filtru. Jsou nalezeny některé vidy a vše je srovnáno s předem známými výsledky. V další fázi práce jsou modely důkladněji zkoumány pomocí parametrických analýz. V poslední fázi práce je aplikována globální optimalizační rutina PSO na admitanční charakteristiku jednoduché 2D struktury. Výsledky jsou porovnány s komerčně vyráběnými součástkami.
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Surface acoustic wave microfluidic chip for rapid cell sorting
Vejrosta, Jakub ; Maňka, Tadeáš ; Plichta, Tomáš ; Šerý, Mojmír
This work revolves around microfluidics and micro-objects manipulation in general. In our device, we are producing surface acoustic wave (SAW). The SAW can be used to sort particles by their size or physical properties and separate them. In medical analysis SAW on microfluidic chip can be used to pre-sorting of body fluids or blood serum for further optical or chemical analysis. The wave is produced by pair of interdigital transducers (IDTs), which are situated on opposite sides of microfluidic channel. As our active material we have used lithium niobate crystalline material for its great piezoelectric properties. This work is also the precursor for measuring the rheological properties of a medium, such as micro-viscosity, via the measurement of the trajectory of a flow trace.
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Nanoscaled polypyrrole for sensing gaseous analytes and volatile organic compounds
Šetka, Milena ; Dian,, Juraj (oponent) ; Mandayo, Gemma García (oponent) ; Drbohlavová, Jana (vedoucí práce)
Polypyrrole (PPy) is a hetero-cyclic conductive polymer (CPs) with chemical structure based on the existence of conjugated electrons between alternating single and double bond system. This polymer has occupied the attention of many scientists from different research disciplines due to its outstanding properties such as good electrical conductivity, relatively high environmental stability, and facile and diversified synthesis methods. The aim of this research was to study the sensing behavior of PPy. Therefore, the gas sensing performances of PPy nanostructures were verified to ‘gas molecules of high importance’ including acetone, ammonia, ethanol, ethylene and toluene. In this work, PPy in the form of nanorods (NRs) and nanoparticles (NPs) was prepared using electrochemical and chemical synthesis approaches, respectively. Additionally, the modified PPy structures were developed by functionalization of PPy NPs with catalytic particles of gold (Au), silver (Ag) and cadmium-telluride (CdTe). Many complementary analytical techniques (microscopic and spectroscopic) were used for the investigation of morphology, composition and structure of the synthesized materials. Moreover, spectroscopy techniques such as Raman and X-Ray Photoelectron Spectroscopy (XPS) were employed for in-situ gas sensing tests, which confirmed the potential of PPy NRs and PPy NPs to be used as gas sensitive materials. In order to developed the gas sensor device, the PPy based materials were integrated into chemo-resistive and Love mode surface acoustic wave (L-SAW) transducing platforms. The gas sensing test of chemo-resistive sensors based on PPy NRs revealed negligible response to nitrogen dioxide and ammonia due to complicate architecture of those sensors. The measuring of response of non-modified and modified PPy NPs chemo-resistive sensors was complex due to their extremely high resistance in G range. However, multi-guiding L-SAW sensors based on bare PPy NPs and modified with Au NPs and Ag NPs, and CdTe quantum dots (QDs) manifested the response to low concentration of all tested target gas molecules including ammonia, acetone, ethanol, ethyleen and toluene at room temperature (RT). Generally, the L-SAW sensors with modified sensing layers established enhanced sensing performances over non-modified sensors. The performance of the L-SAW sensor primarily depends on the operating frequency and the choose of sensitive layer in the active region of the sensor. Thus, among the tested sensing layers for the target gases, modified PPy layer with Ag NPs and/or Au NPs can be selected as the best option for the detection of acetone. The developed PPy based L-SAW sensors are simple and cost effective devices with improved sensing properties such as high sensitivity and low limit of detection (LOD) which make them potential candidates in future systems for air quality control, food quality control or disease diagnosis via exhaled breath.
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Filtr s akustickou povrchovou vlnou
Tichý, Jakub ; Dědková, Jarmila (oponent) ; Raida, Zbyněk (vedoucí práce)
Teoretická část této práce se zabývá principy a vlastnostmi filtru s akustickou povrchovou vlnou. Je zde vysvětlen princip magnetostrikce a piezoelektrického jevu, který filtr využívá. V praktické části jsou v programu Comsol Multiphysics vytvořeny tři jednoduché modely SAW filtru. Jsou nalezeny některé vidy a vše je srovnáno s předem známými výsledky. V další fázi práce jsou modely důkladněji zkoumány pomocí parametrických analýz. V poslední fázi práce je aplikována globální optimalizační rutina PSO na admitanční charakteristiku jednoduché 2D struktury. Výsledky jsou porovnány s komerčně vyráběnými součástkami.
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