Characterization of PVDF material in nanoscale resolution

Tato práce se zabývá charakterizací nanovláken na bázi polyvinylidenfluoridu. Zaměření práce je na piezoelektrické vlastnosti vlákna, které jsou studovány metodou piezoelektrické silové mikroskopie. Takto byly měřeny dva typy odlišných vzorků, které se lišily v parametrech výroby. Odlišnosti vláken v jejich fázovém složení byly také zkoumány za využití Ramanovy spektroskopie a infračervené spektroskopie s Fourierovou transformací. Chemická analýza povrchu a jeho stavu proběhla pomocí rentgenové fotoelektronové spektroskopie. Různé uspořádání nanovláken spolu s jejich průřezem bylo pozorováno rastrovacím elektronovým mikroskopem za využití fokusovaného iontového svazku. Rovněž byla zkoumána smáčivost a kontaktní úhel povrchu vzorků s demineralizovanou vodou. Bylo zjištěno, že vyšší rychlost otáček válce během procesu elektrostatického zvlákňování má velmi významný vliv na jejich uspořádání a tím i na parametry ovlivňující tvorbu piezoelektrického jevu a dalších materiálových vlastností.This work deals with the characterization of nanofibers based on polyvinylidene fluoride. The focus is on the piezoelectric properties of the fiber, which are studied by piezoelectric force microscopy. Thus, two types of different samples were measured, which differed in the fabrication parameters. The differences in the fibers in their phase composition were also investigated using Raman spectroscopy and Fourier-transform infrared spectroscopy. Chemical analysis of the surface and its state was performed using X-ray photoelectron spectroscopy. The different arrangement of the nanofibers together with their cross-section was observed by a scanning electron microscope using focused ion beam. The wettability and contact angle of the surface of the samples with demineralized water were also examined. It was found that the higher speed of the roller during the electrospinning process has a very significant effect on their arrangement and thus on the parameters affecting the formation of the piezoelectric effect and other material properties.

Overview of the Current State of Flexible Solar Panels and Photovoltaic Materials

The rapid growth and evolution of solar panel technology have been driven by continuous advancements in materials science. This review paper provides a comprehensive overview of the diverse range of materials employed in modern solar panels, elucidating their roles, properties, and contributions to overall performance. The discussion encompasses both traditional crystalline silicon-based panels and emerging thin-film technologies. A detailed examination of photovoltaic materials, including monocrystalline and polycrystalline silicon as well as alternative materials such as cadmium telluride (CdTe), copper indium gallium selenide (CIGS), and emerging perovskite solar cells, is presented. Furthermore, the impact of transparent conductive materials, encapsulation polymers, and antireflective coatings on solar panel efficiency and durability is explored. The review delves into the synergistic interplay between material properties, manufacturing processes, and environmental considerations. Through a comprehensiv

A Brief Overview on Epoxies in Electronics: Properties, Applications, and Modifications

This paper offers a short overview of epoxy resins, encompassing their diverse characteristics, variants, chemical modifications, curing processes, and intriguing electrical properties. Epoxies, valued for their multifunctional attributes, serve as fundamental materials across industries. In the realm of dielectric strength, epoxy resins play a crucial role in electrical insulation. This paper discusses the mechanisms governing dielectric breakdown, strategies to enhance dielectric strength, and the impact of various fillers and additives on insulation performance. Through an exploration of recent research and advancements, this paper delves into the spectrum of epoxy properties, the array of subspecies and variants, their chemical adaptability, and the intricacies of curing. The examination of electrical resistance and conductivity, with a focus on their frequency-dependent behavior, forms a pivotal aspect of the discussion. By shedding light on these dimensions, this review provides a concise yet holistic understanding of epoxies and their role in shaping modern materials science

Brief review of PVDF properties and applications potential

Currently, there is an ever-growing interest in carbon materials with increased defor-mation-strength, thermophysical parameters. Due to their unique physical and chemical properties, such materials find a wide range of applications in various industries. Many prospects for the use of polymer composite materials based on polyvinylidene fluoride (PVDF) for scientific and technical purposes explain the plethora of studies on their characteristics "structure-property", processing, application and ecology which keep appearing. Building a broader conceptual picture of new generation polymeric materials is feasible with the use of innovative technologies; thus achieving a high level of multidisciplinarity and integration of polymer science; its fundamental problems are formed, the solution of which determines a significant contribution to the natural-scientific picture of the modern world. This review provides explanation of PVDF advanced properties and potential applications of this polymer material in its various forms. More specifically, this paper will go over PVDF trademarks presently available on the market, provide thorough overview of the current and potential applications. Last but not least, this article will also delve into the processing and chemical properties of PVDF such as radiation carbonization, -phase formation etc

Current applications and challenges of the Internet of Things

The concept of the Internet of Things is capable of making a giant leap in the economy, including research in the field of computer science, network technologies, microelectronics and sensor technology. Combined with the technological developments of nanotechnology and robotics, IoT can play a central role in the industrial revolution by creating economic relations between machines and connecting the economy of people and machines, solving a number of problems that humanity is facing. All devices controlled via the Internet are elements of the Internet of things. The IoT has allowed various possibilities for all countries to improve life quality and the technological ideas for efficiency, productivity, security, and profit. An integrated security system is a giant step towards the improved economy. The concept of IoT plays a decisive role in the further development of the infocommunication industry. This is confirmed both by the position of the International Telecommunication Union (ITU) and the European Union on this issue, and by the inclusion of the Internet of Things in the list of breakthrough technologies in the United States, China and other countries. Thus, this article will go over the current state of the IoT as well as describe which devices and industries stand to benefit from the advantages it brings. Additionally, statistical data on the actual trends and investments into IoT across the world are also provided

A brief introduction and current state of polyvinylidene fluoride as an energy harvester

This review summarizes the current trends and developments in the field of polyvinylidene fluoride (PVDF) for use mainly as a nanogenerator. The text covers PVDF from the first steps of solution mixing, through production, to material utilization, demonstration of results, and future perspective. Specific solvents and ratios must be selected when choosing and mixing the solution. It is necessary to set exact parameters during the fabrication and define whether the material will be flexible nanofibers or a solid layer. Based on these selections, the subsequent use of PVDF and its piezoelectric properties are determined. The most common degradation phenomena and how PVDF behaves are described in the paper. This review is therefore intended to provide a basic overview not only for those who plan to start producing PVDF as energy nanogenerators, active filters, or sensors but also for those who are already knowledgeable in the production of this material and want to expand their existing expertise and current overview of the subject

Structure Tuning and Electrical Properties of Mixed PVDF and Nylon Nanofibers

The paper specifies the electrostatic spinning process of specific polymeric materials, such as polyvinylidene fluoride (PVDF), polyamide-6 (PA6, Nylon-6) and their combination PVDF/PA6. By combining nanofibers from two different materials during the spinning process, new structures with different mechanical, chemical, and physical properties can be created. The materials and their combinations were subjected to several measurements: scanning electron microscopy (SEM) to capture topography; contact angle of the liquid wettability on the sample surface; Raman spectroscopy; X-ray photoelectron spectroscopy (XPS); and Fourier-transform infrared spectroscopy ({FT-IR}) to describe properties and their changes at the chemical level. Crystallization events were determined by differential scanning calorimetry (DSC). Furthermore, the contact angle of the wettability of the liquid on the surface was measured for the materials, and the permittivity was measured to observe the dielectric properties. The advantage of the addition of co-polymers was to control the properties of PVDF samples and understand the reasons for the changed functionality. The innovation point of this work is the complex analysis of PVDF modification caused by mixing with nylon PA6. Here we empathize that the application of nylon during the spin influences the properties and structure (polarization, crystallization) of PVDF

Electronic Circuits for Biomedical Applications

Tato bakalářská práce obsahuje úvod do biomedicínských signálů a možnosti zpracování těchto signálů elektronickými obvody. Významná část práce se zaměřuje především na popis EMG signálu. Součástí práce jsou take schemata elektrických obvodů, které se používají především pro zpracování EMG signálů. Dále má práce praktickou část, v níž byly v simulátoru OrCAD Capture ověřovány funkce a parametry navrženého obvodu

Electronic Circuits for Biomedical Applications

Tato bakalářská práce obsahuje úvod do biomedicínských signálů a možnosti zpracování těchto signálů elektronickými obvody. Významná část práce se zaměřuje především na popis EMG signálu. Součástí práce jsou take schemata elektrických obvodů, které se používají především pro zpracování EMG signálů. Dále má práce praktickou část, v níž byly v simulátoru OrCAD Capture ověřovány funkce a parametry navrženého obvodu.The bachelor’s thesis contains an introduction to biomedical signals and the possibilities of processing those signals by electronic circuits. A significant part of the thesis focuses primarily on the description of EMG signal. Also, the thesis comprises diagrams of electrical circuits used primarily for processing of EMG signals. Furthermore, it includes a practical part, in which functions and parameters of a designed circuit are verified in simulator OrCAD Capture.