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Biomarker detection using electrochemical method with microfluidic chip
Klepáčová, Ivana ; Svoboda, Ondřej (referee) ; Neužil, Pavel (advisor)
The thesis is focused on the development of the electrochemical system with microfluidic platform for the detection of multiple biomarkers. It analyses the use of biomarkers for the early diagnosis of cancer. The theoretical part contains basic information about voltammetric methods and microfluidic systems. The practical part provides solutions to the microfluidic chips, including the description of the used materials, designs, methodologies of preparation and conclusions from the testing of the manufactured microfluidic systems. The thesis describes the lock-in electrochemical system which measures the response of 4 electrochemical cells simultaneously. For the electrochemical system measurements, an electrochemical chip consisting of 64 electrochemical cells was used. The results of the analysis include the processing of the system tests and detected voltammetric curves of the Fe2+/Fe3+ solution and cysteine.
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Microfluidic systems in silicon technology
Juránek, Dominik ; Fecko, Peter (referee) ; Gablech, Imrich (advisor)
This thesis is devoted to the topic of microfluidics and the functionality of microfluidic devices when working with blood. It further focuses on the use of microfluidic devices to cut blood cells. The first part of this work is dedicated to the theoretical background of microfluidics, it briefly introduces the history of microfluidic devices and the materials used for their integration, moreover, it talks about the methods used when constructing a microfluidic device in a silicon substrate. Lastly, this section includes a description of blood and its composition and some properties important for working with microfluidic devices. The practical part is concerned with the (manufacturing procedure of) creating a microfluidic and testing of device that can cut red blood cells.
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Microfluidic devices
Stehlík, Martin ; Sluše, Jan (referee) ; Rudolf, Pavel (advisor)
The bachelor's thesis deals with the phenomenon of mixing fluid in an equipment with micro scale and its production. The first part is dedicated to describe Reynolds, Peclet and Strouhal number. The second part describes micromixers and their distribution. The final part deal´s with specific examples of manufacturing microfluidc devices.
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Cavitation in microfluidics
Holub, Martin ; Kozák, Jiří (referee) ; Rudolf, Pavel (advisor)
Mikrofluidice byla v posledních letech věnována intenzivní pozornost výzkumnými týmy takřka po celém světě. Její možné aplikace jsou velmi početné, zejména pak v oblasti zdravotnictví, ukládání energie do baterií nebo chlazení vysoce výkonných počítačů. Bakalářská práce „Kavitace v mikrofluidice“ se zabývá kavitací na mikro-měřítku. Nedávný výzkum ukazuje, že mnohé charakteristiky kavitujícího proudění na takto malých rozměrech se podstatně liší oproti charakteristikám pozorovaným na konvenčních makro-rozměrech. Toto podtrhuje relevantnost této práce. Lepší pochopení tohoto jevu může být využito například k řešení jednoho ze značných úskalí mikrofluidiky a to sice mísení tekutin, nebo dále také k jejich pumpování. Mezi další možné aplikace se řadí mechanické namáhání a rozklad mikroorganismů a buněk, katalýza chemických reakcí a cílená doprava léčiv. První část této práce je věnována postupně základům z oblasti mechaniky tekutin a chemie kavitace. Tato část je následována stručným přehledem aplikací kavitace a to jak na měřítkách tradičních, tak na měřítkách v řádech mikrometrů. Poté je uveden popis numerického řešení kavitujícího proudění spolu s analýzou a ověřením získaných výsledků. Mezi výsledky je například popis rozložení fází, informace o tom, kde dochází k recirkulaci a také přehled vlivu změny kavitačního čísla na tvar a charakteristiky proudění. V závěrečné části práce je pak na základě získaných znalostí navržen experiment, který umožní dále studovat tuto problematiku a poslouží také k vyhodnocení vhodnosti laminárního modelu. Tato bakalářská práce slouží jako základní kámen pro další výzkum v této oblasti plánovaný na Vysokém učením technickém v Brně, a z tohoto důvodu jsou v textu uvedena doporučení pro další práci.
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Cavitation in microfluidic orifice
Bohunský, Tomáš ; Burda, Radim (referee) ; Rudolf, Pavel (advisor)
This diploma thesis deals with cavitation flow in the microscale, which remains an area with a lack of sufficient description of this phenomenon. At the same time, microfluidics is a field experiencing a dramatic rise in numerous biochemical applications, which underlines the relevance of researches of this type. In theoretical part of the thesis, cavitation was described in detail. In the practical part, a microfluidic device with a cavitation orifice was designed and manufactured. The ANSYS program was used for this design. An experiment was performed with the designed microchip, the aim of which was to observe a cavitating flow on the orifice. This measurement took place at the microfluidic laboratory at Victor Kaplan Department of Fluid Engineering. Due to the failure of the experiment, a CFD model of two-phase cavitation flow was built. The conclusions of the thesis were compiled from the findings of measurement and the results of modeling.
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Optical micromanipulation and Raman spectroscopy of cells in microfluidic systems
Klementová, Tereza ; Samek, Ota (referee) ; Mravec, Filip (advisor)
This diploma thesis deals with optimization of analysis process and measuring antibiotics induced changes in E. coli cells via Raman spectroscopy, LTRS and microfluidic systems. Optical micromanipulation by a laser beam allows noncontact and noninvasive manipulation of objects on scale 10^-5–10^-8 m, for example bacterial cells. Microfluidic device consists of microchannels and microchambers in transparent polymer and it is used for isolation, observation and cultivation of bacterial cells. Combination of these methods gives an effective tool for observation, manipulation and analysis of microorganisms. E. coli is a microorganism potentially pathogenic for humans and faster detection of its sensitivity to antibiotic treatment would make the whole process of diagnostics and treatment easier. We performed laser tweezer-Raman spectroscopy and conventional Raman spectroscopy of bacterial cells and cells under antibiotic stress and collected Raman spectra and characteristic areas were compared with literature to establish the reliability and usefulness of this method.
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Optical Micromanipulation Techniques Combined with Microspectroscopic Methods
Pilát, Zdeněk ; Prášil,, Ondřej (referee) ; Mojzeš, Peter (referee) ; Zemánek, Pavel (advisor)
Předložená dizertační práce se zabývá kombinací optických mikromanipulací s mikrospektroskopickými metodami. Využili jsme laserovou pinzetu pro transport a třídění živých mikroorganismů, například jednobuněčných řas, či kvasinek. Ramanovskou spektroskopií jsme analyzovali chemické složení jednotlivých buněk a tyto informace jsme využili k automatické selekci buněk s vybranými vlastnostmi. Zkombinovali jsme pulsní amplitudově modulovanou fluorescenční mikrospektroskopii, optické mikromanipulace a jiné techniky ke zmapování stresové odpovědi opticky zachycených buněk při různých časech působení, vlnových délkách a intenzitách chytacího laseru. Vyrobili jsme různé typy mikrofluidních čipů a zkonstruovali jsme Ramanovu pinzetu pro třídění mikro-objektů, především živých buněk, v mikrofluidním prostředí.
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Gas Microsensors Based on Self-Organized 3D Metal-Oxide Nanofilms
Pytlíček, Zdeněk ; Husák, Miroslav (referee) ; Kolařík, Vladimír (referee) ; Prášek, Jan (advisor)
This dissertation concerns the development, fabrication and integration in a gas sensing microdevice of a novel 3-dimensional (3D) nanostructured metal-oxide semiconducting film that effectively merges the benefits of inorganic nanomaterials with the simplicity offered by non-lithographic electrochemistry-based preparation techniques. The film is synthesized via the porous-anodic-alumina-assisted anodizing of an Al/Nb metal bilayer sputter-deposited on a SiO2/Si substrate and is basically composed of a 200 nm thick NbO2 layer holding an array of upright-standing spatially separated Nb2O5 nanocolumns, being 50 nm wide, up to 900 nm long and of 8109 cm2 population density. The nanocolumns work as semiconducting nano-channels, whose resistivity is greatly impacted by the surface and interface reactions. Either Pt or Au patterned electrodes are prepared on the top of the nanocolumn array using an innovative sensor design realized by means of microfabrication technology or via a direct original point electrodeposition technique, followed by selective dissolution of the alumina overlayer. For gas-sensing tests the film is mounted on a standard TO-8 package using the wire-bonding technique. Electrical characterization of the 3D niobium-oxide nanofilm reveals asymmetric electron transport properties due to a Schottky barrier that forms at the Au/Nb2O5 or Pt/Nb2O5 interface. Effects of the active film morphology, structure and composition on the electrical and gas-sensing performance focusing on sensitivity, selectivity, detection limits and response/recovery rates are explored in experimental detection of hydrogen gas and ammonia. The fast and intensive response to H2 confirms the potential of the 3D niobium-oxide nanofilm as highly appropriate active layer for sensing application. A computer-aided microfluidics simulation of gas diffusion in the 3D nanofilm predicts a possibility to substantially improve the gas-sensing performance through the formation of a perforated top electrode, optimizing the film morphology, altering the crystal structure and by introducing certain innovations in the electrode design. Preliminary experiments show that a 3D nanofilm synthesized from an alternative Al/W metal bilayer is another promising candidate for advanced sensor applications. The techniques and materials employed in this work are advantageous for developing technically simple, cost-effective and environmentally friendly solutions for practical micro- and nanodevices, where the well-defined nano-channels for charge carriers and surface reactions may bring unprecedented benefits.
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Microfluidic circuit
Zeman, Radek ; Zemanová, Lucie (referee) ; Rudolf, Pavel (advisor)
Microfluidics is a science dealing with flow of a very small amounts of fluids and is mainly connected with medicine and biochemistry. One of a main problem, which this science is facing, is a difficult mixing of fluids due to occurrence of laminar flows. This bachelor thesis contains a design of a microfluidic circuit with Staggered herringbone microfluidic mixer and subsequent implementation of the experiment according to the performed design.
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