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Nekonvenční metody měření proudu a napětí
Talába, Michal ; Boušek, Jaroslav (oponent) ; Hubálek, Jaromír (vedoucí práce)
Diplomová práca sa zaoberá rešeršou nekonvenčných metód merania prúdu a napätia a následným zostrojením prototypu prúdového senzora na báze magnetorezistívneho materiálu pre vysokonapäťový rozvádzač firmy ABB. Výstupom rešerše je popis jednotlivých metód z hľadiska fyzikálneho a z hľadiska spôsobu merania. Výstupom praktickej časti je prúdový senzor osadený magnetorezistívnou súčiastkou schopný merať magnetické pole v okolí vodiča cez ktorý preteká primárny prúd a tým určiť veľkosť primárneho prúdu. Senzor bol meraný v rozsahu 0 až 1000 A, pričom dosahoval hodnoty presnosti a linearity približne 6%. Hlavným prínosom práce je potvrdenie funkčnosti nekonvenčnej metódy pre meranie vysokých prúdov. Na základe výsledkov má firma ABB možnosť rozhodnutia, či je daná technológia perspektívna pre jej produktové portfólio.
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Elektronický detektor pro tenkovrstvé mikrosenzory plynů
Rozštípil, Jakub ; Stehlík, Jiří (oponent) ; Hubálek, Jaromír (vedoucí práce)
Hlavním cílem diplomové práce je navrhnout a realizovat elektroniku v podobě SMT přístroje pro tenkovrsvé senzory plynů a nastudovat princip funkce senzorů plynů na bázi polovodivých oxidů. Přístroj obsahuje regulátor teploty a elektroniku, jež je schopna snímat koncentraci plynů na povrchu senzoru. Zařízení je navrženo pro řízení 4 senzorů a má komunikovat s počítačem pro nastavení počátečních podmínek a snímání koncentrace plynu. Praktická část diplomové práce obsahuje návrh a realizaci elektroniky a tvorbu softwaru pro její ovládání.
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Design and Simulation of Micro-Bolometer in MEMS Technology
Svatoš, Vojtěch ; Pekárek, Jan (oponent) ; Hubálek, Jaromír (vedoucí práce)
This master thesis studies the infrared detector called bolometer. The task is to improve the infrared detection by using different type of absorption layer modified by the carbon nanotubes. In theoretical part there are basic terms of thermal engineering and basics definitions of bolometer physics. The bolometer design is presented and described. The thermal mechanical simulations are evaluating the operation behavior. PSpice model of bolometer is created combing the thermal and electrical properties of the bolometer chip. The fabrication process is then presented and detailed described.
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New technique on a chip for rapid detection of biological materials
Pejović Simeunović, Jelena ; Foret,, František (oponent) ; Táborský,, Petr (oponent) ; Hubálek, Jaromír (vedoucí práce)
This work proposes a technique for on-chip separation and detection of quantum dots (QDs) conjugated with various proteins in order to study the inuence of the coupling agent on a quenching of QD uorescence intensity caused by conjugation to a protein and to perform multi-analyte immunoassay to identify small amounts of the protein. Under optimal conditions, bioconjugated QDs were successfully separated from free QDs within 10 minutes. Particles and target solutions were mixed, and on-chip detection was performed using a device developed in our laboratory. Only one excitation light source was used in combination with several filters for different emission wavelengths. Fluorescence emitted by the two types of conjugated QDs could then be recorded simultaneously since the QDs emitted light at different wavelengths while being excited at the same wavelength. By mixing two types of QDs bioconjugated with two kinds of proteins and antibodies we were able to detect immunocomplex peaks with varying areas. The peak area depended on concentration of QDs and antigens, on the progress of antibody-antigen reaction and proved to be linearly correlated with the antigen concentration. We showed that on-chip capillary electrophoresis of QDs can be used as a sensitive technique for detection of biological molecules. The main benefits of this method are simplicity, small sample and reagent volume requirements, and high efciency of separation.
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Energy harvester working on epidermis
Fecko, Peter ; Prášek, Jan (oponent) ; Hubálek, Jaromír (vedoucí práce)
This work focuses on theoretical designing of a device harvesting energy from perspiration on human epidermis. Chemical composition of the human sweat was researched from articles and publications dealing with this problem. Following their results the approximate concentration values of ionic salts (and other substances) were established, also an adequate combination of electrode metals were examined, theoretically making the energy harvester functional. Next proposal described a draft and production procedures towards manufacturing the harvester. Evaluation of voltage stability and dependency was made on changes in ionic concentrations of the electrolyte, representing human sweat. Finally, the harvester cell was produced according to proposed manufacturing methods and the cell performance was measured.
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Přístroj pro monitorování prostředí při kultivaci rostlin
Žák, Jaromír ; Kuchta, Radek (oponent) ; Hubálek, Jaromír (vedoucí práce)
Hlavním cílem této práce je vytvoření elektronického zařízení provádějícího monitoring fyzikálních vlastností okolního prostředí, jenž ovlivňují růst a vývoj rostlin. Nové zařízení má nahradit stávající mechanický zapisovač hodnot teploty a vlhkosti na Mendelově zemědělské a lesnické univerzitě v Brně. Nové zařízení je navíc rozšířeno o měření atmosférického tlaku, osvětlení a koncentrace CO2. Hlavním přínosem této nové koncepce zařízení bude přesnější měření veličin a taktéž přehlednější zobrazování získaných hodnot a jejich srovnávání s dřívějšími výsledky uloženými v počítači, než tomu bylo doposud na získaných papírových grafech.
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New nanodevices for electronics - fabrication and characterization
Márik, Marian ; Husák,, Miroslav (oponent) ; Mikulík,, Petr (oponent) ; Hubálek, Jaromír (vedoucí práce)
This work proposes a technique for fabrication of a self-ordered nanostructures for electrical applications. The devices were prepared by anodic oxidation in two lengths and three different heat treatments. The structural characterization using SEM, TEM and EDX technics, respectively, were evaluated from structural and material point of view as well. The unique root structure of the highly self-ordered nanocolumn arrays was evaluated and compared after three different heat treatments: as anodized, vacuum annealed and air annealed, respectively. The possible crystallographic orientation of the columns was not observed, however the nano-crystallites under the root structures were found. The electrical study about the devices shown resistive switching behavior (RS), diode like behavior and a capacitive coupled diode like behavior as well. The active surface, from RS point of view, for the switching mechanism is at the top of the nanocolumns and the gold top electrode. The Schottky barrier height of the Ti/TiO2 interface was calculated with two methods, and it was lower than 1,11 eV for all three devices.
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PROGRESS TOWARD THE DEVELOPMENT OF SINGLE NANOWIRE-BASED ARRAYS FOR GAS SENSING APPLICATIONS
Chmela, Ondřej ; Vrňata, Martin (oponent) ; Macák, Jan (oponent) ; Hubálek, Jaromír (vedoucí práce)
This thesis presents the development of silicon-based platforms for selective integration of semiconducting metal oxide (MOX) nanostructures and their use as highly sensitive and selective elements for the detection of gas analytes in prospective mobile devices. Semiconducting MOX nanostructures, for instance nanowires, have proved better gas sensing properties including sensitivity, stability and to a certain extent also selectivity as compared to their bulk counterparts. The use of single (or few) nanowire structures connected in parallel has also shown to be the ideal architecture to achieve well-defined conduction channel easy to modulate by the gas-solid interactions. However, yet current methods for the integration of single nanowire structures in functional devices represent a technological challenge, with most of the methods needing the assistance of techniques, such as focused-ion beam (FIB), which restricts the scalability of the process and increases the cost and time of fabrication. In this context, this work is focused on the search and optimization of technological processes to fabricate gas sensing systems based on arrays of single semiconducting nanowires. In this thesis, three versions of electrode platforms were developed for the selective integration of single gas-sensitive metal oxide nanowires. State-of-the-art multistep throughput fabrication techniques, as well as electron-beam lithography (nanofabrication), were used as crucial fabrication technologies allowing the development of arrays with faced nanoelectrodes and other functional nanostructures. Results show the fabrication of electrode platform with faced nanoelectrodes (100 – 300 nm width) framed in narrow dielectric windows close to the nanowire diameter (100 – 200 nm approx.). These nanoelectrodes were used as both mechanical support to align the single nanowire, and electrical contacts to measure the electrical change along the nanowire during gas detection. Results also include the optimization of techniques for removal and redeposition of nanowires to achieve single nanowire interconnections in the array of parallel electrodes using an alternating electric field as a simple and effective technique for nanowires alignment (dielectrophoresis). The validation of these systems toward various gaseous species (oxidizing and reducing gases) was performed using non-functionalized and Pt-functionalized WO3 nanowires synthesized by aerosol-assisted chemical vapor deposition (AACVD) and backside ceramic heaters (with the operating temperature at 250 °C) assembled on TO-8 package. The sensing parameters of such systems showed better sensing responses in resistive regime to nitrogen dioxide (NO2) and ethanol (EtOH) than their counterparts based on multiple nanowire-based films. The last version of gas sensing systems developed in this thesis (described as third chip generation) includes a third insulated electrode buried under the gas sensitive nanowire for enhanced gas sensing regime. Gas sensing tests of this system to hydrogen (H2) and nitrogen dioxide (NO2) corroborated the enhanced functionality of these systems and the modulation of sensor response by applying external electrical stimuli on the buried electrode.
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Patterning of excitable cells on multi-electrode arrays
Slavík, Jan ; doc. RNDr. Petr. Skládal, CSc. (oponent) ; Průcha,, Jaroslav (oponent) ; Hubálek, Jaromír (vedoucí práce)
The work deals with the alignment of excitable cells on multielectrode arrays. First, the alignment of excitable cells was analyzed. Embryonic neurons from rat hippocampus and HL-1 cells, which are derived from the AT-1 line of tumor mouse atrial cardiomyocytes, were used. Alignment was tested on ridged surfaces and on surfaces with materials with different cellular affinities. It was demonstrated, that both neurons and HL-1 cells aligned in direction of ridges on ridges surface, but only neurons aligned on surface with different chemical affinity. Further, own multielectrode arrays were made, the HL-1 cells were cultured on the multielectrode arrays, and the action potentials of the HL-1 cells were measured and analyzed. The aim was to prove that it is possible to measure the action potential on the fabricated multi-electrode arrays. A special multielectrode array with a uniform surface was made to align cells on a multielectrode array. This multielectrode array is called a planar multielectrode array. The planar multielectrode arrays were made by a special fabrication process. The layers of the planar multielectrode array were deposited on the sacrificial substrate in the reverse order. The sacrificial substrate for deposition was silicon wafer on which was deposited another sacrificial layer from gold. The upper insulating layer of planar multielectrode array was deposited first and the lowest substrate layer was deposited last. Then the planar multielectrode array with the sacrificial gold layer was peeled off from silicon due to the low adhesion of gold to silicon and planar multielectrode array turned upside down. The sacrificial gold layer was removed by a wet etchant and planar multielectrode array was finished. On a planar multielectrode array, the HL-1 cells were patterned into strips by a chemical method using a combination of microprinting of an adhesive agent and subsequent coating by an anti-adhesive agent of not microprinted areas. The electrophysiological properties of aligned HL-1 cells were measured using the planar multielectrode array. By this experiment, it was introduced fabrication technology for fabrication of planar multielectrode arrays and the planar multielectrode array was successfully tested for HL-1 cells alignment on its surface by combination of microprinting of an adhesive agent and anti-adhesive agent coating.
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Topná membrána typu MEMS s nízkým příkonem
Svatoš, Vojtěch ; Pekárek, Jan (oponent) ; Hubálek, Jaromír (vedoucí práce)
Cílem této práce je realizovat MEMS topnou membránu s nízkým příkonem. Práce obsahuje základní body návrhu a přehled technologií, které jsou určeny pro výrobu těchto topných elementů. Jako výchozí struktura pro realizaci topné membrány byl vybrán typ závěsné membrány. Na závěr této práce je uveden detailní technologický postup, který byl použit při výrobě finálních struktur a experimentální ověření odolnosti proti teplotnímu namáhání.
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