Investigation of the phase delay of radiation by a transparent ferroelectric polymer film

In this paper, we study samples of an optically transparent ferroelectric polymer film with deposited nanoscale electrically conductive coatings designed to modulate the transmitted electromagnetic radiation of the visible and near-infrared wavelengths. Such films can be used, for example, in interference devices for phase delay compensation or for the implementation of the Phase Shifting Interferometry, in adaptive optics, etc. To measure the phase delay of the radiation passing through the samples under study, an installation based on the Mach-Zehnder interferometer was used. In the illumination branch of the installation, a broadband radiation source and an acousto-optic tunable filter are installed; in one of the arms of the interferometer, the test sample is installed. The interference pattern was recorded on a matrix radiation receiver; the phase information was decoded by digital holography methods. The report presents the results of measurements and shows that a modulation of the passed optical radiation occurs under the influence of the electric field as a result of changes in the geometrical dimensions of the film.

Импульсный магнитный контроль толщины металлических покрытий

The research results of the characteristics of magneto-inductive thickness gauges measuring transducers using harmonic excitation currents for the case of inspecting electrically conductive coatings are presented, on the basis of which a transducing algorithm is proposed and described in detail, which involves pulsed excitation of a magnetic field and the use of the induced EMF area as a primary informative parameter when suppressing the influence of network and pulse noise, used in serial thickness gauges of metallic non-ferromagnetic coatings on ferromagnetic substrates.

CREATION OF COMPOSITE ELECTRICALLY CONDUCTIVE COATINGS BY GAS DYNAMIC SPRAYING

The article presents the results of research of spraying processes of composite electrically conductive coatings using copper C01-11 and aluminum A20-11 powders in order to determine the effect of components on each other in the formation of cold gas-dynamic spraying (CGDS) and the development of recommendations for the introduction of additional component to obtain a composite coating with a given ratio of different components. For example, when at a working air temperature of 300 ° C the copper sputtering coefficient is almost zero, it is a search for the experimental dependence of the sputtering coefficient change depending on the percentage of components of copper and aluminum powders in the sprayed mixture and determination of their residual content in the coating. based on the obtained data of the sputtering coefficients of copper and aluminum. The CGDS method obtained blanks with composite coatings from mixtures of powders of aluminum A20-11 and copper C01-11 at different initial concentrations of aluminum by weight (from 0 to 100% with a step of 10%) under otherwise equal conditions (air pressure 0,6 MPa, temperature air heating 300 ° C). The sputtering coefficient of a mixture of copper and aluminum and the residual content of components in the sprayed composite coatings were found. Data on the residual content of the individual components in the sprayed coating allows to determine the composition of the source powder required for spraying a given content of each of the components in the coating. The dependences of the spraying coefficients of copper C01-11 and aluminum A20-11 on the mass content of aluminum in the sprayed mixture were found. When the initial concentration of aluminum is less than 66%, the coefficient of copper deposition is greater than the coefficient of deposition of aluminum. Both increase with increasing concentration of aluminum until it reaches 61%. At high concentrations of aluminum (more than 66%) the spray coefficients of copper, aluminum and their mixtures coincide. The results obtained on the residual content of the components in the coating allow you to select the composition of the source powder required to obtain the desired content of components in the coating. For example, the maximum residual copper content (~ 95%) can be obtained by adding 30-40% aluminum to the starting powder. The obtained results prove the influence of the components on each other and justify the amount of introduction of an additional component for spraying a composite coating containing a component that is difficult to spray.

Structural, Microstructural and Electrochemical Studies of Co/Mn Derived Oxides as Protective Layers for Intermediate Temperature SOFCs

Designing highly protective and superior electrically conductive coatings from Cobalt-manganese doped/un-doped oxide materials (CMOs) is the main target of this study. The as-prepared nanopowders were synthesized via glycine nitrate process (GNP) at moderate annealing temperature afterword characterized using several techniques including X-rays diffraction (XRD), Field emission scanning electron microscopy (FE-SEM) and electrochemical impedance measurements at room temperature. The XRD results revealed a pure phase of spinel structure with particle size range 75-81 nm for the doped CMO samples. SEM micrographs exhibited morphology with fine aggregate of particles. The incorporation of different ions of Cu, Ni, Fe and Na into the CMOs structure showed a significant increase in the diffusivity of ions and remarkable improvement in the crystallinity. AC electrical conductivity was also measured for the compacted pellets after sintering at 850°C using the electrochemical impedance spectroscopy technique at room temperature. From the obtained results it could be concluded that the polarization resistance of pure and modified CMOs samples show similar behavior ranged from 5 to 6 k Ω.

Characterisation of Electrical and Stiffness Properties of Conductive Textile Coatings with Metal Flake-Shaped Fillers

Two conductive formulations containing different types of micron-sized metal flakes (silver-coated copper (Cu) and pure silver (Ag)) were characterised and used to form highly electrically conductive coatings (conductors) on plain and base-coated woven fabrics, the latter in an encapsulated construction. With e-textiles as the intended application, the fabric stiffness, in terms of flexural stiffness and sheet resistance (Rsh), after durability testing (laundering and abrasion) was investigated and related to user friendliness and long-term performance. Bare and encapsulated conductors with increasing amounts of deposited solids were fabricated by adjusting the knife coating parameters, such as the coating gap height (5, 20, 50, and 200 μm), which reduced the Rsh, as determined by four-point probe (4PP) measurements; however, this improvement was at the expense of increased flexural stiffness of the coated fabrics. The addition of a melamine derivative (MF) as a cross-linker to the Cu formulation and the encapsulation of both conductor types gave the best trade-off between durability and Rsh, as confirmed by 4PP measurements. However, the infrared camera images revealed the formation of hotspots within the bare conductor matrix, although low resistances (determined by 4PP) and no microstructural defects (determined by SEM) were detected. These results stress the importance of thorough investigation to assure the design of reliable conductors applied on textiles requiring this type of maintenance.

Electrically Conductive Coatings for Fiber-Based E-Textiles

With the advent of wearable electronic devices in our daily lives, there is a need for soft, flexible, and conformable devices that can provide electronic capabilities without sacrificing comfort. Electronic textiles (e-textiles) combine electronic capabilities of devices such as sensors, actuators, energy harvesting and storage devices, and communication devices with the comfort and conformability of conventional textiles. An important method to fabricate such devices is by coating conventionally used fibers and yarns with electrically conductive materials to create flexible capacitors, resistors, transistors, batteries, and circuits. Textiles constitute an obvious choice for deployment of such flexible electronic components due to their inherent conformability, strength, and stability. Coating a layer of electrically conducting material onto the textile can impart electronic capabilities to the base material in a facile manner. Such a coating can be done at any of the hierarchical levels of the textile structure, i.e., at the fiber, yarn, or fabric level. This review focuses on various electrically conducting materials and methods used for coating e-textile devices, as well as the different configurations that can be obtained from such coatings, creating a smart textile-based system.