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Energy harvester working on epidermis
Fecko, Peter ; Prášek, Jan (referee) ; Hubálek, Jaromír (advisor)
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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Thick-film sensors for heavy metals detection
Gajdoš, Libor ; Majzlíková, Petra (referee) ; Prášek, Jan (advisor)
This project describes the possibilities of heavy metals detections in solutions using differential pulse voltammetry with tree-electrode electrochemical thick-film sensors. In the theoretical part, the thick-film technology is described as well as thick-film pastes’ types and compositions, followed by introduction to electrochemistry and electro-analytical methods of measurement. This project also describes the three measured heavy metals – cadmium, lead and copper. In the practical part, heavy metals’ ions detection in solutions using carbon working electrode and determination of the detection limit and sensitivity are described and discussed. Finally the evaluation of obtained results and results comparison to hygienic limits are included.
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Carbon nanotubes utilization for fabrication of thick-film sensors electrodes
Polický, Jiří ; Adámek, Martin (referee) ; Prášek, Jan (advisor)
This work covers an area of heavy metals detection by miniaturized thick film sensors. Working electrode of these sensors was fabricated using thick film paste that was prepared as a nanocomposition of carbon nanotubes powder, suitable vehicle and a thinner. The response of fabricated electrodes to cadmium and lead ions was measured using differential pulse voltammetry in an acetate buffer solution using a three electrode sytem. The results were compared with the carbon electrode made from special commercial thick film polymer paste. Finally the possibility of working electrode surface activation with nitric acid and heavy metals on real biological sample detection is described here.
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MEMS based energy harvesting
Klempa, Jaroslav ; Prášek, Jan (referee) ; Gablech, Imrich (advisor)
This work is dedicated to principles of energy harvesting or scavenging from free energy around us. Energy harvesting principles are described in the first part. Following chapter is devoted to description of piezoelectricity and piezoelectric materials. Next part researches already reported results on piezoelectric energy harvesters. Following chapter shows simulations on designed structures in ANSYS® Workbench. Next the fabrication of the structures is described. Measurement are made regarding to maximum generated power.
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Gas sensors, their construction and testing
Zbožínek, Štěpán ; Prášek, Jan (referee) ; Pytlíček, Zdeněk (advisor)
The presented bachelor´s thesis deals with gas sensors, their construction and methods of testing. First part shortly describes the problems of gas detection. There are introduced common principles, constructions, examples of possible applications and requirements, which should be complied with gas sensors. In more detail, there are described conductivity gas sensors. Main purpose of the work is draft software equipment determined for compiled mixing station. For check correct function of the program was also done several measurements with gas sensors containing active layer SnO2 created for oxygen detection. In conclusion, there is on the base of collected theoretical pieces of knowledge and measured information discussed accuracy of measurement, and limits of usability station.
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Three-electrode electrochemical sensor characterization
Koporec, Lukáš ; Prášek, Jan (referee) ; Majzlíková, Petra (advisor)
This bachelor thesis is focused on the thick-film three-electrode electrochemical sensor characterization. In the theoretical part, the thesis describes thick-film technology, standard electrodes used in electrochemistry to detect substances as well as electroanalytical methods for solutions analysis. The experimental part is dedicated to the procedures used in the characterization of the three-electrode electrochemical sensor and their evaluation.
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Optimization of electrochemical sensor for detection in microvolume
Gajdoš, Libor ; Pekárek, Jan (referee) ; Prášek, Jan (advisor)
This thesis describes optimization and modification of standard thick-film electrochemical sensor to be able to be used for detection in microvolumes. In the theoretical part, the thick film technology is described. The work is then focused on the wettability of surfaces followed by introduction to electrochemistry and electro-analytical methods. In the experimental part, screen-printing of various types of thick film pastes on ceramic substrates for determination of their wettability and the following modification of the sensors with thick-film paste and with Parylene vaporization can be found, as well as the basic electrochemical measurements in microvolume using the modified sensor. Finally the results are summarized in conclusion.
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Thick-film sensors for heavy metals detection
Polický, Jiří ; Adámek, Martin (referee) ; Prášek, Jan (advisor)
This work covers an area of heavy metals detection using thick-film sensors. Fabrication of screen-printed thick-film sensor and electrochemical analytical methods for detection of chemical elements in aqueous solutions are described in this work. Several commercial and own prepared thick-film pastes were used for carbon based working electrodes. The electrochemical properties of the pastes were examined by cadmium ions detection in potassium chloride solution using differential pulse voltammetry. The best results were achieved on the electrode made of direct grown carbon nanotubes on the electrode layer NM22. A detection limit 20×10-6 mol l-1.was reached with this working electrode material during oxidation process.
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