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Piezoelectric nanofiber materials for wearable electronics
Frolíková, Štěpánka ; Škarvada, Pavel (referee) ; Macků, Robert (advisor)
This thesis deals with the influence of production parameters on the morphology of PVDF nanofibers produced by electrospinning. Nanofibers are generally a widely used material, nanofibers are generally a widely used material, they can also have piezoelectric properties, which gives them a specific spectrum of use, eg in biosensors. The production of nanofibers was realized by electrospinning. A scanning electron microscope was used to examine the morphology and surface properties. The aim of this thesis is to compare the properties of PVDF nanofibers produced under different settings of production parameters.
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PiezoLegs motor in medical aplication
Plass, Petr ; Koláčný, Josef (referee) ; Ondrák, Tomáš (advisor)
The Bachelor’s thesis is focused to explain of basic conceptions of piezoelectric motors including principles of piezoelectric effect. It is analysed velocities of movement of PiezoWave motor during loading and he is valued supply voltage of used demo driver. Then it is considered of drive with stepper motor and DC motor, it is compared them with piezoelectric motor and chosen the best alternate for the drive of a pump of the artificial heart. Then it is introduced with working in a program i-Speed 2 to analyzing of shots catch by the high speed video camera and it is given a basic manual to connecting, setting and programming of the drive connected to the EPOS P driving unit.
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Surface acoustic wave filter
Tichý, Jakub ; Dědková, Jarmila (referee) ; Raida, Zbyněk (advisor)
The theoretical part of this thesis deals with principles and characteristics of the surface acoustic wave filter. It explained the principle of magnetostriction and piezoelectric effect, which uses a filter. In the practical part in the program Comsol Multiphysics are made three simple models of SAW filter. Some modes are founded and are compared to previously known results. In the next phase of project is further studied using the parametric analysis. In the last phase of project is applied global optimization PSO at admittance characteristic from simple 2D structure. The results are compared with the commercially produced devices.
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Preparation and optimization of electrospun materials suitable as electricity generators
Pokorná, Romana ; Holcman, Vladimír (referee) ; Tofel, Pavel (advisor)
This master's thesis is focused on energy harvesting and is divided into two parts: theoretical and practical part. The theoretical part of the thesis contains the dielectric parameters, the meaning of the piezoelectric and triboelectric effect and the principles of electric energy gain in energy havesting. The last chapter of the theoretical part is devoted to various electrospun materials suitable for energy harvesting. The practical part of the work deals with nanofibers as an energy generator and describes their dielectric parameters. In this part the relative permittivity and loss factor of selected types of nanofibers are measured. Also the triboelectric nanogenerator is made and it's properties are measured.
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Smart Structures with Integrated Piezoelectric Materials
Pinček, Ladislav ; Hrstka, Miroslav (referee) ; Hadaš, Zdeněk (advisor)
Táto práca sa venuje skúmaniu smart materiálových vlastností auxetickej štruktúry s elektromechanickou premenou vyvinutej na VUT. Práca sa postupne v jednotlivých bodoch zaoberá zostavovaním laboratórnych vzoriek smart materiálového systému, experimentálnym vyšetrovaním elektromechanických parametrov, dizajnom modelu a návrhom technických aplikácii. Pre danú štruktúru bolo navrhnutých viacero technických využití. Navrhované technické využitia boli experimentálne alebo simulačne skúmané a bol vyhodnotený potenciál pre ďalší výskum.
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Development of PVDF nanofibers sensor
Klásek, Matyáš ; Tofel, Pavel (referee) ; Hadaš, Zdeněk (advisor)
This diploma thesis deals with the feasibility of using PVDF nanofibers as an active sensor layer generating electrical signal. PVDF and related electromechanical effects are described. A research study is conducted regarding existing PVDF nanofiber applications and based on it, an event sensor design utilizing triboelectric effect and electrostatic induction is proposed. The electrical response of the layers is experimentally investigated and a pulse detection algorithm is conceived and implemented. Finally, a way of integrating the sensor into a rail track is proposed.
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Analysis of passive and semi-active damping of cantilever oscillation
Václavík, Tomáš ; Tofel, Pavel (referee) ; Hadaš, Zdeněk (advisor)
In this thesis passive and semi-active damping methods on a model of cantilever beam with piezoelectric patch are analyzed. Explanation of piezoelectric effect, classification of damping methods used for vibration control, description of their properties, their benefits and disadvantages, and lastly the challanges of their implementation is presented. Models of specified methods are carried out in MATLAB Simulink and the results are compared. Basic concept of electrical design of circuits for semi-active damping by SDDNC and SSD methods is introduced.
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Analytical model of composite cantilever with SMART layer
Dostal, Vojtěch ; Ševeček, Oldřich (referee) ; Majer, Zdeněk (advisor)
This bachelor's thesis deals with analytical modelling of composite cantilever with smart layer. The structure is based on the real piezoelectric generator, which is a solid cantilever beam with a layer of piezoelectric material attached to its bottom and top. The first part of this bachelor's thesis summarizes the knowledge of the energy harvesting, the process under which harvesting of electric energy from the piezoelectric generator belongs. Some piezoelectric materials are mentioned and described afterwards. At first, analytical modelling is implemented on the homogeneous cantilever beam. Then, the relations for required characteristics are derived for laminate structure, which is structurally similar to the piezoelectric generator. One chosen parameter will be changeable. Due to the ties of relations, the required characteristics will change as well, which are for the piezoelectric generator strain and deflection.
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Measurement of the piezoelectric charge coefficient
Stehno, David ; Uher, Miroslav (referee) ; Fialka, Jiří (advisor)
The thesis aim was to study in theory the determination of piezoelectric coefficients, in particular piezoelectric coefficient of charge and to use different measurement methods to determine this factor. Also to further study the issue of determining the uncertainties and determine the measurement uncertainty. Measurements were conducted on cylinder-shaped samples, with different dimensions of individual samples. With type material PCM51 and PCM41. Piezoelectric coefficient measurements of charge was carried out using three methods: frequency, direct and quasi-static. The results achieved by all methods are compared at the end of this study and the measurements uncertainty are calculated and discussed for each method.
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