TY - JOUR A1 - Stadler, Dominik A1 - Hofmann, Matthias J. A1 - Motschmann, Hubert A1 - Shamonin (Chamonine), Mikhail T1 - Automated system for measuring the surface dilational modulus of liquid-air interfaces JF - Measurement Science and Technology N2 - The surface dilational modulus is a crucial parameter for describing the rheological properties of aqueous surfactant solutions. These properties are important for many technological processes. The present paper describes a fully automated instrument based on the oscillating bubble technique. It works in the frequency range from 1 Hz to 500 Hz, where surfactant exchange dynamics governs the relaxation process. The originality of instrument design is the consistent combination of modern measurement technologies with advanced imaging and signal processing algorithms. Key steps on the way to reliable and precise measurements are the excitation of harmonic oscillation of the bubble, phase sensitive evaluation of the pressure response, adjustment and maintenance of the bubble shape to half sphere geometry for compensation of thermal drifts, contour tracing of the bubbles video images, removal of noise and artefacts within the image for improving the reliability of the measurement, and, in particular, a complex trigger scheme for the measurement of the oscillation amplitude, which may vary with frequency as a result of resonances. The corresponding automation and programming tasks are described in detail. Various programming strategies, such as the use of MATLAB (R) software and native C++ code are discussed. An advance in the measurement technique is demonstrated by a fully automated measurement. The instrument has the potential to mature into a standard technique in the fields of colloid and interface chemistry and provides a significant extension of the frequency range to established competing techniques and state-of-the-art devices based on the same measurement principle. KW - automated measurements KW - dilational modulus KW - graphical user interfaces KW - Image processing KW - oscillating bubble technique KW - signal processing KW - STABILITY KW - surface rheology Y1 - 2016 U6 - https://doi.org/10.1088/0957-0233/27/6/065301 VL - 27 IS - 6 PB - IOP PUBLISHING ER - TY - JOUR A1 - Belyaeva, Inna A. A1 - Kramarenko, Elena Yu A1 - Stepanov, Gennady V. A1 - Sorokin, Vladislav V. A1 - Stadler, Dominik A1 - Shamonin (Chamonine), Mikhail T1 - Transient magnetorheological response of magnetoactive elastomers to step and pyramid excitations JF - SOFT MATTER N2 - Transient rheological response of magnetoactive elastomers is experimentally studied using dynamic torsion at a fixed oscillation frequency in temporally stepwise changing magnetic fields and oscillation amplitudes. For step magnetic-field excitations, at least three exponential functions are required to reasonably describe the time behavior of the storage shear modulus over long time scales (>10(3) s). The deduced characteristic time constants of the corresponding rearrangement processes of the filler network differ approximately by one order of magnitude: tau(1) less than or similar to 10(1) s, tau(2) similar to 10(2) s, and tau(3) similar to 10(3) s. The sudden imposition of the external magnetic field activates a very fast rearrangement process with the characteristic time under 10 s, which cannot be determined more precisely due to the measurement conditions. Even more peculiar transient behavior has been observed during pyramid excitations, when either the external magnetic field was first stepwise increased and then decreased in a staircase manner at a fixed strain amplitude gamma or the strain amplitude gamma was first stepwise increased and then decreased in a staircase manner at a fixed magnetic field. In particular, the so-called "cross-over effect'' has been identified in both dynamical loading programs. This cross-over effect seems to be promoted by the application of the external magnetic field. The experimental results are discussed in the context of the specific rearrangement of the magnetic filler network under the simultaneous action of the external magnetic field and shear deformation. Striking similarities of the observed phenomena to the structural relaxation processes in glassy materials and to the jamming transition of granular materials are pointed out. The obtained results are important for fundamental understanding of material behavior in magnetic fields as well as for the development of devices on the basis of magnetoactive elastomeric materials. KW - AMPLITUDE KW - BEHAVIOR KW - DEPENDENCE KW - FLUID KW - HOMOGENEOUS MAGNETIC-FIELD KW - NORMAL FORCE KW - OSCILLATORY SHEAR KW - TIME KW - VISCOELASTIC PROPERTIES Y1 - 2016 U6 - https://doi.org/10.1039/c5sm02690c VL - 12 IS - 11 SP - 2901 EP - 2913 PB - ROYAL SOC CHEMISTRY ER - TY - CHAP A1 - Shamonin (Chamonine), Mikhail A1 - Kramarenko, Elena Yu ED - Domracheva, Natalia ED - Caporali, Maria ED - Rentschler, Eva T1 - Highly Responsive Magnetoactive Elastomers (Chapter 7) T2 - Novel Magnetic Nanostructures N2 - This chapter introduces composite smart materials known as magnetoactive (MAEs) or magnetorheological elastomers. It starts by defining these materials and distinguishing them from relevant magnetorheological fluids and ferrofluids. It then gives the overview of constitutive materials for the polymer matrix and filler particles. Next, the influence of external magnetic field on physical properties of MAEs is discussed. The emphasis is made on mechanical properties, which are the most important for real-world applications. In particular, magnetomechanical effects such as magnetostriction, magnetodeformation, and magnetorheological effect are discussed. The magnetic Payne effect is presented as an example of a nonlinear behavior. Electromagnetic and acoustic properties are also considered. The chapter finishes with the brief discussion of the future prospects in research and development of MAEs. Y1 - 2018 SN - 9780128135945 U6 - https://doi.org/10.1016/B978-0-12-813594-5.00007-2 SP - 221 EP - 245 PB - Elsevier ER - TY - JOUR A1 - Burdin, Dmitrii A. A1 - Ekonomov, Nikolai A. A1 - Chashin, Dmitri V. A1 - Fetisov, Leonid Y. A1 - Fetisov, Yuri K. A1 - Shamonin (Chamonine), Mikhail T1 - Temperature Dependence of the Resonant Magnetoelectric Effect in Layered Heterostructures JF - Materials N2 - The dependence of the resonant direct magnetoelectric effect on temperature is studied experimentally in planar composite structures. Samples of rectangular shapes with dimensions of 5 mm x 20 mm employed ferromagnetic layers of either an amorphous (metallic glass) alloy or nickel with a thickness of 20-200 m and piezoelectric layers of single crystalline langatate material or lead zirconate titanate piezoelectric ceramics with a thickness of 500 m. The temperature of the samples was varied in a range between 120 and 390 K by blowing a gaseous nitrogen stream around them. It is shown that the effective characteristics of the magnetoelectric effectsuch as the mechanical resonance frequency f(r), the quality factor Q and the magnitude of the magnetoelectric coefficient (E) at the resonance frequencyare contingent on temperature. The interrelations between the temperature changes of the characteristics of the magnetoelectric effect and the temperature variations of the following material parametersYoung's modulus Y, the acoustic quality factor of individual layers, the dielectric constant epsilon, the piezoelectric modulus d of the piezoelectric layer as well as the piezomagnetic coefficients ((n)) of the ferromagnetic layerare established. The effect of temperature on the characteristics of the nonlinear magnetoelectric effect is observed for the first time. The results can be useful for designing magnetoelectric heterostructures with specified temperature characteristics, in particular, for the development of thermally stabilized magnetoelectric devices. KW - acoustic quality factor KW - composite structure KW - linear KW - magnetoelectric effect KW - magnetoelectric heterostructure KW - magnetostriction KW - nonlinear KW - piezoelectric KW - temperature dependence Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-32185 N1 - corresponding author: Mikhail Shamonin VL - 10 IS - 10 PB - MDPI ER - TY - JOUR A1 - Nadzharyan, Timur A. A1 - Shamonin (Chamonine), Mikhail A1 - Kramarenko, Elena Yu T1 - Theoretical Modeling of Magnetoactive Elastomers on Different Scales: A State-of-the-Art Review JF - Polymers N2 - A review of the latest theoretical advances in the description of magnetomechanical effects and phenomena observed in magnetoactive elastomers (MAEs), i.e., polymer networks filled with magnetic micro- and/or nanoparticles, under the action of external magnetic fields is presented. Theoretical modeling of magnetomechanical coupling is considered on various spatial scales: from the behavior of individual magnetic particles constrained in an elastic medium to the mechanical properties of an MAE sample as a whole. It is demonstrated how theoretical models enable qualitative and quantitative interpretation of experimental results. The limitations and challenges of current approaches are discussed and some information about the most promising lines of research in this area is provided. The review is aimed at specialists involved in the study of not only the magnetomechanical properties of MAEs, but also a wide range of other physical phenomena occurring in magnetic polymer composites in external magnetic fields. KW - magnetodeformation KW - magnetorheological effect KW - mechanical properties KW - magnetic particles KW - theoretical modeling KW - magnetorheological elastomersn KW - magnetoactive elastomers Y1 - 2022 U6 - https://doi.org/10.3390/polym14194096 VL - 14 IS - 19 SP - 1 EP - 42 PB - MDPI ER - TY - JOUR A1 - Snarskii, Andrei A. A1 - Podlasov, Sergii A1 - Shamonin (Chamonine), Mikhail T1 - Isotropic inertia tensor without symmetry of mass distribution JF - American Journal of Physics N2 - Conventional calculations of the inertia tensor in undergraduate physics course are usually done for highly symmetrical bodies. Students might therefore get the impression that the moment of inertia about any axis through the center of mass is the same only for bodies with the highest degree of symmetry relative to this point, e.g., for spheres. A simple, seemingly counterintuitive example is presented, showing that the moment of inertia of a non-regular body, here an assembly of material points, can be the same about any axis passing through its center of mass. Y1 - 2021 U6 - https://doi.org/10.1119/10.0005416 VL - 89 IS - 10 SP - 916 EP - 920 PB - AIP Publishing ER - TY - JOUR A1 - Bodnaruk, Andrii V. A1 - Brunhuber, Alexander A1 - Kalita, Viktor M. A1 - Kulyk, Mykola M. A1 - Snarskii, Andrei A. A1 - Lozenko, Albert F. A1 - Ryabchenko, Sergey M. A1 - Shamonin (Chamonine), Mikhail T1 - Temperature-dependent magnetic properties of a magnetoactive elastomer: Immobilization of the soft-magnetic filler JF - Journal of Applied Physics N2 - The magnetic properties of a magnetoactive elastomer (MAE) filled with mu m-sized soft-magnetic iron particles have been experimentally studied in the temperature range between 150 K and 310 K. By changing the temperature, the elastic modulus of the elastomer matrix was modified, and it was possible to obtain magnetization curves for an invariable arrangement of particles in the sample and in the case when the particles were able to change their position within the MAE under the influence of magnetic forces. At low (less than 220 K) temperatures, when the matrix becomes rigid, the magnetization of the MAE does not show a hysteresis behavior, and it is characterized by a negative value of the Rayleigh constant. At room temperature, when the polymer matrix is compliant, a magnetic hysteresis exists where the dependence of the differential magnetic susceptibility on the magnetic field exhibits local maxima. The appearance of these maxima is explained by the elastic resistance of the matrix to the displacement of particles under the action of magnetic forces. KW - BEHAVIOR KW - composites KW - FIELD KW - GELS KW - hysteresis KW - Magnetorheological elastomers KW - MICROSTRUCTURE KW - PERMEABILITY KW - RAYLEIGH LAW KW - STRAIN Y1 - 2018 U6 - https://doi.org/10.1063/1.5023891 VL - 123 IS - 11 PB - AIP Publishing ER - TY - JOUR A1 - Kalita, Viktor M. A1 - Snarskii, Andrei A. A1 - Zorinets, Denis A1 - Shamonin (Chamonine), Mikhail T1 - Single-particle mechanism of magnetostriction in magnetoactive elastomers JF - Physical Review E N2 - Magnetoactive elastomers (MAEs) are composite materials comprised of micrometer-sized ferromagnetic particles in a nonmagnetic elastomermatrix. Asingle-particle mechanism ofmagnetostriction in MAEs, assuming the rotation of a soft magnetic, mechanically rigid particle with uniaxial magnetic anisotropy in magnetic fields is identified and considered theoretically within the framework of an alternative model. In this mechanism, the total magnetic anisotropy energy of the filling particles in the matrix is the sum over single particles. Matrix displacements in the vicinity of the particle and the resulting direction of the magnetization vector are calculated. The effect of matrix deformation is pronounced well if the magnetic anisotropy coefficient K is much larger than the shear modulus mu of the elastic matrix. The feasibility of the proposed magnetostriction mechanism in soft magnetoactive elastomers and gels is elucidated. The magnetic-field-induced internal stresses in the matrix lead to effects of magnetodeformation and may increase the elastic moduli of these composite materials. KW - BEHAVIOR KW - Deformation KW - DEPENDENCE KW - FERROGELS KW - HOMOGENEOUS MAGNETIC-FIELD KW - magnetodeformation KW - MICROSTRUCTURE KW - SENSITIVE ELASTOMERS Y1 - 2016 U6 - https://doi.org/10.1103/PhysRevE.93.062503 VL - 93 IS - 6 PB - American Physical Society ER - TY - JOUR A1 - Saveliev, Dmitri A1 - Chashin, Dmitri V. A1 - Fetisov, Leonid Y. A1 - Shamonin (Chamonine), Mikhail A1 - Fetisov, Yuri K. T1 - Ceramic-Heterostructure-Based Magnetoelectric Voltage Transformer with an Adjustable Transformation Ratio JF - Materials N2 - A voltage transformer employing the magnetoelectric effect in a composite ceramic heterostructure with layers of a magnetostrictive nickel–cobalt ferrite and a piezoelectric lead zirconate–titanate is described. In contrast to electromagnetic and piezoelectric transformers, a unique feature of the presented transformer is the possibility of tuning the voltage transformation ratio K using a dc magnetic field. The dependences of the transformer characteristics on the frequency and the amplitude of the input voltage, the strength of the control magnetic field and the load resistance are investigated. The transformer operates in the voltage range between 0 and 112 V, and the voltage transformation ratio K is tuned between 0 and 14.1 when the control field H changes between 0 and 6.4 kA/m. The power at the transformer output reached 63 mW, and the power conversion efficiency was 34%. The methods for calculation of the frequency response, and the field and load characteristics of the transformer are proposed. The ways to improve performance characteristics of magnetoelectric transformers and their possible application areas are discussed. KW - magnetoelectric effect KW - piezoelectric effect KW - voltage transformer KW - composite material KW - magnetostriction Y1 - 2020 U6 - https://doi.org/10.3390/ma13183981 VL - 13 IS - 18 SP - 1 EP - 13 PB - MDPI ER - TY - JOUR A1 - Snarskii, Andrei A. A1 - Zorinets, Denis A1 - Shamonin (Chamonine), Mikhail A1 - Kalita, Viktor M. T1 - Theoretical method for calculation of effective properties of composite materials with reconfigurable microstructure BT - Electric and magnetic phenomena JF - Physica A: Statistical Mechanics and its Applications N2 - We propose a theoretical approach for calculating effective electric and magnetic properties of composites, with field dependent restructuring of the filler. The theory combines the effective medium approximation, extended to a field-dependent (variable) percolation threshold, with an approximate treatment of the nonlinearity of material properties. Theoretical results are compared with experiments on magnetorheological elastomers, which in the context of investigated phenomena are often called magnetoactive elastomers (MAEs). In MAEs with soft polymer matrices, the mutual arrangement of inclusions changes in an applied magnetic field. This reorganization of the microstructure leads to unconventionally large changes of electrical and magnetic properties. The obtained theoretical results describe observed phenomena in MAEs well. For the magnetodielectric effect, qualitative agreement between theory and experiment is demonstrated. In the case of magnetic permeability, quantitative agreement is achieved. The theoretical approach presented can be useful for the development of field-controlled smart materials and design of intelligent structures on their basis, because the field dependence of physical properties can be predicted. (C) 2019 Elsevier B.V. All rights reserved. KW - CONDUCTIVITY KW - EFFECTIVE RESPONSE KW - magnetoactive elastomers KW - PERCOLATION KW - PERMEABILITY Y1 - 2019 U6 - https://doi.org/10.1016/j.physa.2019.122467 VL - 535 IS - December PB - Elsevier ER - TY - JOUR A1 - Kostrov, Sergei A. A1 - Shamonin (Chamonine), Mikhail A1 - Stepanov, Gennady V. A1 - Kramarenko, Elena Yu T1 - Magnetodielectric Response of Soft Magnetoactive Elastomers: Effects of Filler Concentration and Measurement Frequency JF - International Journal of Molecular Sciences N2 - The magnetodielectric response of magnetoactive elastomers (MAEs) in its dependence on filler concentration, magnetic field, and test frequency is studied experimentally. MAEs are synthesized on the basis of a silicone matrix filled with spherical carbonyl iron particles characterized by a mean diameter of 4.5 mu m. The concentration of the magnetic filler within composite materials is equal to 70, 75, and 80 mass%. The effective lossless permittivity epsilon as well as the dielectric loss tan grow significantly when the magnetic field increases. The permittivity increases and the dielectric loss decreases with increasing filler concentration. In the measurement frequency range between 1 kHz and 200 kHz, the frequency hardly affects the values of epsilon and tan in the absence of a magnetic field. However, both parameters decrease considerably with the growing frequency in a constant magnetic field. The more strongly the magnetic field is applied, the larger the change in permittivity and loss tangent at the same test frequency is observed. An equivalent circuit formulation qualitatively describes the main tendencies of the magnetodielectric response. KW - dielectric loss KW - magnetic filler KW - MAGNETIC-FIELD KW - magnetoactive elastomers KW - magnetodielectric effect KW - permittivity Y1 - 2019 U6 - https://doi.org/10.3390/ijms20092230 VL - 20 IS - 9 SP - 1 EP - 13 PB - MDPI CY - Basel ER - TY - JOUR A1 - Bodnaruk, Andrii V. A1 - Kalita, Viktor M. A1 - Kulyk, Mykola M. A1 - Lozenko, Albert F. A1 - Ryabchenko, Sergey M. A1 - Snarskii, Andrei A. A1 - Brunhuber, Alexander A1 - Shamonin (Chamonine), Mikhail T1 - Temperature blocking and magnetization of magnetoactive elastomers JF - Journal of Magnetism and Magnetic Materials N2 - The magnetization of a magnetoactive elastomer (MAE) with microparticles of soft magnetic carbonyl iron embedded in a highly elastic matrix has been studied. It is shown that at high temperatures its magnetization curve has the form of a specific hysteresis loop. This hysteresis is attributed to the influence of displacement of magnetized particles in the elastically soft elastomer matrix under the effect of magnetic forces, leading to the change of magnetic interaction between the particles. In this case, there is a maximum in the field dependence of the magnetic susceptibility, the occurrence of which has been associated with the competition between rearrangement of particles, when they are displaced in a magnetic field, and saturation of particles' magnetization. When the MAE is cooled below approximately 225 K, both the magnetic hysteresis and the maximum in the field dependence of the magnetic susceptibility disappear. When the MAE material is cooled below the solidification temperature of the elastomer matrix, the displacements of the magnetic particles during magnetization are blocked by the rigid matrix. The magnetization reversal of the MAE is reversible. This means that the shape of subsequent magnetization loops remains constant and the sample returns into the initial non-magnetized state after the magnetic field is turned off. KW - Hysteresis loop KW - Magnetization reversal KW - magnetoactive elastomer KW - Magnetorheological elastomers KW - MICROSTRUCTURE KW - Solidification Y1 - 2019 U6 - https://doi.org/10.1016/j.jmmm.2018.10.005 VL - 471 IS - February SP - 464 EP - 467 PB - Elsevier ER - TY - JOUR A1 - Fetisov, Yuri K. A1 - Chashin, Dmitri V. A1 - Saveliev, Dmitri A1 - Fetisov, Leonid Y. A1 - Shamonin (Chamonine), Mikhail T1 - Anisotropic Magnetoelectric Effect in a Planar Heterostructure Comprising Piezoelectric Ceramics and Magnetostrictive Fibrous Composite JF - Materials N2 - The direct magnetoelectric (ME) effect is investigated in a planar structure comprising mechanically coupled layers of a magnetostrictive fibrous composite (MFC) and a piezoelectric ceramics (lead zirconate titanate, PZT). The MFC is an array of Ni-wires with a diameter of 200 mu m that are aligned parallel to each other in a single layer. The wires are separated by a distance of 250 or 500 mu m and fixed in a polyamide matrix. The structure was placed in a tangential constant field H and was excited by an alternating magnetic field h parallel to H, while the voltage generated by the PZT layer was measured. The resulting field dependences of the magnetization M(H) and the magnetostriction lambda(H) were determined by the orientation of the field H in the plane of the structure and the distance between the Ni-wires. The ME coupling coefficient of the structure decreased from 4.8 to 0.25 V/A when the orientation of H was changed from parallel to perpendicular to Ni-wires. With an increase in the excitation field amplitude h, a nonlinear ME effect in the output voltage, namely frequency doubling, was observed. The frequency and field dependences of the efficiency of the ME transduction in the MFC-piezoelectric heterostructure are well described by the existing theory. KW - composite KW - frequency doubling KW - heterostructure KW - magnetoelectric effect KW - magnetostrictive fiber KW - piezoelectric ceramic material Y1 - 2019 U6 - https://doi.org/10.3390/ma12193228 N1 - Corresponding authors: Yuri Fetisov, Mikhail Shamonin VL - 12 IS - 19 SP - 1 EP - 13 PB - MDPI CY - Basel ER - TY - JOUR A1 - Bodnaruk, A1 - Andrii V., A1 - Brunhuber, Alexander A1 - Kalita, Viktor M. A1 - Kulyk, Mykola M. A1 - Kurzweil, Peter A1 - Snarskii, Andrei A. A1 - Lozenko, Albert F. A1 - Ryabchenko, Sergey M. A1 - Shamonin (Chamonine), Mikhail T1 - Magnetic anisotropy in magnetoactive elastomers, enabled by matrix elasticity JF - Polymer N2 - Polydimethylsiloxane based magnetoactive elastomers demonstrate above the melting transition range (e.g. at room temperature) an induced uniaxial magnetic anisotropy, which grows with increasing magnetic field. By freezing a material down to 150 K, displaced iron microparticles are immobilized, so that the magnetic anisotropy can be measured. Magnetic anisotropy “constant” is a consequence of particle displacements and a characteristic of the energy of internal deformations in the polymer matrix. The maximum anisotropy constant of the filling is at least one order of magnitude larger than the shear modulus of the pure elastomer (matrix). In a magnetic field, the gain in the rigidity of the composite material is attributed to the magnetomechanical coupling, which is in turn a source of anisotropy. The concept of effective magnetic field felt by the magnetization allows one to explain the magnetization curve at room temperature from low-temperature measurements. The results can be useful for developing vibration absorbers and isolators. KW - Experimental methodology KW - Internal deformation KW - magnetic properties KW - magnetoactive elastomer KW - Magnetomechanical coupling KW - magnetorheological elastomer Y1 - 2019 U6 - https://doi.org/10.1016/j.polymer.2018.12.027 VL - 162 IS - January SP - 63 EP - 72 PB - Elsevier ER - TY - JOUR A1 - Snarskii, Andrei A. A1 - Kalita, Viktor M. A1 - Shamonin (Chamonine), Mikhail T1 - Renormalization of the critical exponent for the shear modulus of magnetoactive elastomers JF - Scientific Reports N2 - It is shown that the critical exponent for the effective shear modulus of a composite medium where a compliant polymer matrix is filled with ferromagnetic particles may significantly depend on the external magnetic field. The physical consequence of this dependence is the critical behavior of the relative magnetorheological effect. Y1 - 2018 U6 - https://doi.org/10.1038/s41598-018-22333-6 N1 - Corresponding author: Mikhail Shamonin VL - 8 SP - 1 EP - 8 PB - Nature ER - TY - JOUR A1 - Forster, Eva A1 - Mayer, Matthias A1 - Rabindranath, Raman A1 - Böse, Holger A1 - Schlunck, Günther A1 - Monkman, Gareth J. A1 - Shamonin (Chamonine), Mikhail T1 - Patterning of ultrasoft, agglutinative magnetorheological elastomers JF - Journal of applied polymer science N2 - A low-cost wax-cast molding technique for structuring ultrasoft (Young’s modulus ≤ 40 kPa), agglutinative magnetorheological elastomer (MRE) material is presented. MRE structures ranging from a few millimeters down to the micrometer range with highly reproducible results are possible. Semitransparent MREs are also fabricated and their surfaces modified accordingly. This method opens new possibilities for MREs in biomedical engineering and microfluidic applications. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013 Y1 - 2013 U6 - https://doi.org/10.1002/app.38500 VL - 128 IS - 4 SP - 2508 EP - 2515 PB - Wiley CY - New York, NY ER - TY - JOUR A1 - Hesmer, Frank A1 - Tatartschuk, Eugen A1 - Zhuromskyy, Oleksandr A1 - Radkovskaya, Anna A. A1 - Shamonin (Chamonine), Mikhail A1 - Hao, Tong A1 - Stevens, Chris J. A1 - Faulkner, Grahame A1 - Edwards, David J. A1 - Shamonina, Ekaterina T1 - Coupling mechanisms for split ring resonators: Theory and experiment JF - Physica status solidi b N2 - We study experimentally and theoretically coupling mechanisms between metamaterial elements of the split ring resonator (SRR) type. We show that, depending on the orientation of the elements relative to each other, the coupling may be either of magnetic or electric type or a combination of both. Experimental results on SRRs with resonances around 1.7–1.9 GHz agree quantitatively with results of simulations (CST Microwave Studio). Further simulations provide analysis for a variety of SRRs both in the GHz and in the 20 THz frequency regions. The variety of coupling mechanisms can be employed in designing near field manipulating devices based on propagation of slow waves. Y1 - 2007 U6 - https://doi.org/10.1002/pssb.200674501 VL - 244 IS - 4 SP - 1170 EP - 1175 PB - Wiley ER - TY - JOUR A1 - Sydoruk, O. A1 - Radkovskaya, Anna A. A1 - Zhuromskyy, Oleksandr A1 - Shamonina, Ekaterina A1 - Shamonin (Chamonine), Mikhail A1 - Stevens, Chris J. A1 - Faulkner, Grahame A1 - Edwards, David J. A1 - Solymar, L. T1 - Tailoring the near-field guiding properties of magnetic metamaterials with two resonant elements per unit cell JF - PHYSICAL REVIEW B N2 - A theoretical and experimental study of magnetic metamaterials with unit cells containing two resonant elements is presented. The properties of these structures, consisting of split rings, are governed by strongly anisotropic magnetic coupling between individual elements. This coupling leads to propagation of slow magnetoinductive waves in the vicinity of the resonant frequency. The wavelength of magnetoinductive waves is much smaller than the free-space wavelength of the electromagnetic radiation. This opens up the possibility of manipulating the near field on a subwavelength scale. We develop a theoretical formulation for coupled chains of metamaterial elements allowing the tailoring of their guiding properties in the near field. In a comprehensive analysis modes of coupled waveguides supporting forward and/or backward waves are identified and the corresponding hybridization mechanisms for dispersion equations of magnetoinductive waves are determined. Analytical predictions are verified both experimentally and numerically on a variety of coupled waveguides. The approach can be employed for the design of near-field manipulating devices. Y1 - 2006 U6 - https://doi.org/10.1103/PhysRevB.73.224406 VL - 73 IS - 22 PB - APS ER - TY - JOUR A1 - Radkovskaya, Anna A. A1 - Shamonin (Chamonine), Mikhail A1 - Stevens, Chris J. A1 - Faulkner, Grahame A1 - Edwards, David J. A1 - Shamonina, Ekaterina A1 - Solymar, L. T1 - An experimental study of the properties of magnetoinductive waves in the presence of retardation JF - Journal of Magnetism and Magnetic Materials N2 - Magnetoinductive (MI) waves owe their existence to the magnetic coupling between metamaterial elements. First experiments confirming the existence of MI waves were carried out on capacitively loaded loops and Swiss Rolls about three orders of magnitude smaller than the operating wavelengths (5–15 m) so that the radiation effects did not play any significant role. In the present paper MI waves are studied experimentally on various types of split ring resonators of about 1 cm diameter operating in the microwave region between 1 and 2 GHz. Our results prove that retardation has a significant effect upon the propagation of MI waves. Y1 - 2006 U6 - https://doi.org/10.1103/physrevb.73.224406 VL - 300 IS - 1 SP - 29 EP - 32 PB - Elsevier ER - TY - JOUR A1 - Radkovskaya, Anna A. A1 - Shamonin (Chamonine), Mikhail A1 - Stevens, Chris J. A1 - Faulkner, Grahame A1 - Edwards, David J. A1 - Shamonina, Ekaterina A1 - Solymar, L. T1 - Resonant frequencies of a combination of split rings: Experimental, analytical and numerical study JF - Microwave and Optical Technoly Letters N2 - The resonant frequencies of five different ring resonators are measured with the aid of a network analyser within the frequency range of about 1.5 to 2.8 GHz. The resonant frequencies for those configurations are also determined from numerical calculations using the commercially available MICRO-STRIPES package. The experimental and numerical results are shown to be very close to each other. Analytical results from various authors, available for three of the configurations, are also compared with the experimental results; one of them leads to a large discrepancy, but the other analytical approximations are shown to be not too far off. Y1 - 2005 U6 - https://doi.org/10.1002/mop.21021 VL - 46 IS - 5 SP - 473 EP - 476 PB - Wiley ER - TY - JOUR A1 - Shamonin (Chamonine), Mikhail A1 - Shamonina, Ekaterina A1 - Kalinin, V. A1 - Solymar, L. T1 - Resonant frequencies of a split-ring resonator: Analytical solutions and numerical simulations JF - Microwave and optical technology letters N2 - A set of differential equations describing the current andvoltage distribution in a split-ring resonator is derived and solved ana-lytically. The resonant frequencies may be obtained from the solution of a characteristic equation. An approximate solution for the lowest reso-nant frequency agrees with that obtained by heuristic arguments. The analytical results are supported by numerical simulations KW - metamaterial KW - split-ring resonator KW - resonant frequencies KW - equivalent distributed circuit KW - characteristic equation Y1 - 2004 U6 - https://doi.org/10.1002/mop.20567 VL - 44 IS - 2 SP - 133 EP - 136 PB - Wiley ER - TY - JOUR A1 - Shamonin (Chamonine), Mikhail A1 - Shamonina, Ekaterina A1 - Kalinin, V. A1 - Solymar, L. T1 - Properties of a metamaterial element: Analytical solutions and numerical simulations for a singly split double ring JF - Journal of Applied Physics N2 - An equivalent circuit, consisting of bulk and distributed elements, is derived for describing the properties of a potential metamaterial element capable of providing negative effective permeability. It is the singly split double ring (SSDR), a special case of the split ring resonator (J. B. Pendry et al., IEEE Trans. Microwave Theory Tech. 47, 2075 (1999)), obtained when the gap capacitance in the inner ring is infinitely large. The variables are the inter-ring voltage and the currents flowing in the inner and outer rings. The excitation is assumed in the form of a spatially constant temporally varying magnetic field. The functions, showing the angular variation of the variables, are found by solving a set of differential equations with boundary conditions imposed at the position of the split. It is shown from the analytical solution that the SSDR can have resonant frequencies in the full spectrum from very low to very high frequencies. It is pointed out in particular that whenever the mean diameter of the ring is equal to an odd multiple of the half wavelength it is always possible to find a set of parameters which will give rise to resonance. As examples the resonant frequencies are determined for eight sets of parameters. Results are also derived by replacing the distributed circuit with a number of discrete circuits. It is finally shown that the results obtained from the equivalent circuit model are in excellent agreement with those derived from the MICRO-STRIPES numerical package which solves Maxwell’s equations in the time domain. Y1 - 2004 U6 - https://doi.org/10.1063/1.1652251 VL - 95 IS - 7 PB - AIP ER - TY - JOUR A1 - Klank, Michael A1 - Hagedorn, Oliver A1 - Holthaus, Carsten A1 - Shamonin (Chamonine), Mikhail A1 - Dötsch, Horst T1 - Characterization and optimization of magnetic garnet films for magneto-optical visualization of magnetic field distributions JF - NDT & E International N2 - Rare-earth iron garnet films with in-plane anisotropy grown on (111)-oriented substrates can be used as magneto-optical indicator films for visualization of magnetic leakage fields in nondestructive evaluation. The influence of Faraday rotation, Faraday ellipticity, absorption and film thickness on the performance of a magneto-optical indicator film is investigated. A new optimization method is introduced and compared with the method of contrast optimization. The theory is experimentally verified and an application example is presented. KW - Magneto-optics KW - Imaging KW - Magnetic flux leakage KW - Garnet films Y1 - 2003 U6 - https://doi.org/10.1016/S0963-8695(03)00012-4 VL - 36 IS - 6 SP - 375 EP - 381 PB - Elsevier ER - TY - JOUR A1 - Apelsmeier, Andreas A1 - Schmauss, Bernhard A1 - Shamonin (Chamonine), Mikhail T1 - Compensation of parasitic losses in an extrinsic fiber-optic temperature sensor based on intensity measurement JF - Sensors and Actuators A: Physical N2 - A method of referencing in an extrinsic optical fiber sensor system utilizing temperature dependence of the absorption edge in a semiconductor crystal (semi-insulating iron-doped indium phosphide) is demonstrated. The intensity reference is provided by controlling the temperature of an LED source and transmission measurements with different emission spectra. A transient operation regime is introduced. The entire process is controlled by a microprocessor unit. The performance of the sensor system is investigated and it is shown that the connector losses may be compensated for. Contrary to the published works performed with GaAs crystals it was not observed that the absorption coefficient of the semiconductor follows the law for idealized direct-gap semiconductor but can be described by the so-called Urbach tail. Since the proposed sensor system comprises a single LED source, simple electronics and no optical fiber couplers it is promising for realization of low-cost fiber-optic temperature sensors, e.g. for power transformer monitoring or magnetic resonance imaging applications. KW - Extrinsic optical fiber sensor KW - Temperature measurement KW - Intensity measurement KW - Intensity referencing KW - Indium phosphide KW - Transient operation Y1 - 2012 U6 - https://doi.org/10.1016/j.sna.2011.10.015 VL - 173 IS - 1 SP - 49 EP - 54 ER - TY - JOUR A1 - Apelsmeier, Andreas A1 - Gleixner, Ramona A1 - Mayer, Matthias A1 - Shamonin (Chamonine), Mikhail A1 - Schmauss, Bernhard T1 - Intensity referencing in an extrinsic optical fiber temperature sensor JF - Procedia Engineering N2 - Optical fiber sensors based on intensity measurement require some form of intensity referencing to avoid errors arising from parasitic losses. Known techniques of referencing such as balanced bridge, divided beam systems or two-wavelength referencing are not suitable for low-cost applications since they use relatively complicated optical components such as multiple LED sources, couplers, filters etc. In this work a novel method of referencing in an extrinsic optical fiber sensor system utilizing temperature dependence of absorption edge in a semiconductor crystal is described. The sensor system comprises a single LED source and no optical fiber junctions. The emission spectrum of an LED depends on its temperature. The reference is provided by controlling the temperature of an LED source and transmission measurements with different emission spectra. The entire process is controlled by a microprocessor unit. Performance of a sensor system is investigated and it is shown that the losses in connectors may be compensated for. KW - Extrinsic optical fiber sensor KW - Intensity referencing KW - Temperature measurement KW - Absorption edge KW - Semiconductor KW - Hot-spot measurement Y1 - 2010 U6 - https://doi.org/10.1016/j.proeng.2010.09.301 VL - 5 SP - 1095 EP - 1098 PB - Elsevier ER - TY - JOUR A1 - Trautner, Ralph A1 - Schmauss, Bernhard A1 - Shamonin (Chamonine), Mikhail T1 - Herstellung und Charakterisierung eines extrinsischen faseroptischen Elementarsensors zur Temperaturmessung JF - tm - Technisches Messen N2 - Es werden Herstellung und Charakterisierung eines faseroptischen Elementarsensors zur Temperaturmessung vorgestellt. Der Sensorkopf in Form eines Prismas aus Indiumphosphid nutzt die Temperaturabhängigkeit der Absorptionskante des Halbleitermaterials. Aufgrund der Abmessungen des Prismas im Grenzbereich von Feinmechanik zu Mikrosystemtechnik ist ein angepasstes Herstellungsverfahren notwendig. T2 - Manufacture and Characterization of an Extrinsic Elementary Fiber-Optical Sensor for Temperature Measurement KW - Extrinsic fiber optic sensor KW - indiumphosphide KW - temperature measurement KW - manufacturing method KW - characterization Y1 - 2008 U6 - https://doi.org/10.1524/teme.2008.0866 VL - 75 IS - 10 PB - De Gruyter ER - TY - JOUR A1 - Kreitmeier, Florian A1 - Chashin, Dmitri V. A1 - Fetisov, Yuri K. A1 - Fetisov, Leonid Y. A1 - Schulz, Irene A1 - Monkman, Gareth J. A1 - Shamonin (Chamonine), Mikhail T1 - Nonlinear Magnetoelectric Response of Planar Ferromagnetic-Piezoelectric Structures to Sub-Millisecond Magnetic Pulses JF - Sensors N2 - The magnetoelectric response of bi- and symmetric trilayer composite structures to pulsed magnetic fields is experimentally investigated in detail. The structures comprise layers of commercially available piezoelectric (lead zirconate titanate) and magnetostrictive (permendur or nickel) materials. The magnetic-field pulses have the form of a half-wave sine function with duration of 450 µs and amplitudes ranging from 500 Oe to 38 kOe. The time dependence of the resulting voltage is presented and explained by theoretical estimations. Appearance of voltage oscillations with frequencies much larger than the reciprocal pulse length is observed for sufficiently large amplitudes (~1-10 kOe) of the magnetic-field pulse. The origin of these oscillations is the excitation of bending and planar acoustic oscillations in the structures. Dependencies of the magnetoelectric voltage coefficient on the excitation frequency and the applied magnetic field are calculated by digital signal processing and compared with those obtained by the method of harmonic field modulation. The results are of interest for developing magnetoelectric sensors of pulsed magnetic fields as well as for rapid characterization of magnetoelectric composite structures. Y1 - 2012 U6 - https://doi.org/10.3390/s121114821 N1 - Corresponding author: Mikhail Shamonin VL - 12 IS - 11 SP - 14821 EP - 14837 PB - MDPI CY - Basel ER - TY - CHAP A1 - Kreitmeier, Florian A1 - Schulz, Irene A1 - Monkman, Gareth J. A1 - Shamonin (Chamonine), Mikhail A1 - Fetisov, Yuri K. A1 - Chashin, Dmitri V. A1 - Fetisov, Leonid Y. T1 - Observation of Nonlinear Magnetoelectric Response to Magnetic Pulses in Layered Magnetostrictive-Piezoelectric Structures N2 - A detailed experimental study of the magnetoelectric response of planar bi- and symmetric trilayer composite structures to magnetic field pulses is reported. The structures consist of layers of commercially available piezoelectric (lead zirconate titanate) and magnetostrictive (permendur or nickel) materials. The magnetic-field pulses have the form of a half-wave sine function with duration of 450 μs and amplitude from 500 Oe up to 38 kOe. The measurement method is explained and the measured time dependence of the resulting voltage is presented. The most interesting case, when pulse amplitudes are sufficiently large (~ 1-10 kOe) and various types of acoustic oscillation with frequencies much larger than the reciprocal pulse length are excited in the structures, is considered. The dependencies of the magnetoelectric voltage coefficient on the excitation frequency and the applied magnetic field are calculated. By digital signal processing the results are compared with those obtained by the method of harmonic field modulation (HFM). The findings are of interest for developing magnetoelectric sensors for pulsed magnetic fields as well as for rapid characterization of magnetoelectric composite structures. T2 - Proceedings of 2012 21st IEEE ISAF held jointly with 11th IEEE ECAPD and IEEE PFM (ISAF/ECAPD/PFM), 9th-13th of July 2012, Aveiro, Portugal KW - composite materials KW - magnetoelectric effect KW - magnetoelectric sensors KW - magnetostriction KW - piezoelectricity KW - magnetic field pulse Y1 - 2012 U6 - https://doi.org/10.1109/ISAF.2012.6297739 PB - IEEE ER - TY - GEN A1 - Sorokin, Vladislav V. A1 - Stepanov, Gennady V. A1 - Vasiliev, V. G. A1 - Kramarenko, Elena Yu A1 - Mayer, M. A1 - Shamonin (Chamonine), Mikhail A1 - Monkman, Gareth J. T1 - Investigation of Dynamic Modulus and Normal Force of Magnetorheological Elastomers with Soft and Hard Magnetic Fillers T2 - NANO 2014, July 13 – 18, 2014, Moscow ; Section 06 - Polymer, Organic and Other Soft Matter Materials Y1 - 2014 CY - Moscow ER - TY - JOUR A1 - Stoll, Andrea A1 - Mayer, Matthias A1 - Monkman, Gareth J. A1 - Shamonin (Chamonine), Mikhail T1 - Evaluation of highly compliant magneto-active elastomers with colossal magnetorheological response JF - Journal of applied polymer science N2 - Highly compliant elastomers with a shear storage modulus as low as 25 Pa are prepared using commercially available silicone, plasticizer, and tactile mutator silicone additive. They are used as matrix material for magneto-active elastomers (MAEs) with carbonyl iron contents between 0 and 85 wt %. In the absence of an external magnetic field, the storage modulus of MAEs based on two selected mixtures ranges between ~100 Pa and ~2000 Pa. Addition of a mutator to the matrix mixture results in a long post-cure period depending on the curing temperature and the initial mixture. In the presence of a magnetic field, the presented MAEs exhibit a strong magneto-induced change in storage modulus resulting in a colossal magnetorheological effect of >106 % which is ~30 times higher than previously reported values. The results are of interest in applications using such elastomers as cell substrates with magnetically tunable rigidity. Y1 - 2014 U6 - https://doi.org/10.1002/app.39793 SN - 1097-4628 SN - 0021-8995 PB - Wiley CY - New York, NY ER - TY - JOUR A1 - Mayer, Matthias A1 - Rabindranath, Raman A1 - Börner, Juliane A1 - Hörner, Eva A1 - Bentz, Alexander A1 - Salgado, Josefina A1 - Han, Hong A1 - Böse, Holger A1 - Probst, Jörn A1 - Shamonin (Chamonine), Mikhail A1 - Monkman, Gareth J. A1 - Schlunck, Günther T1 - Ultra-Soft PDMS-Based Magnetoactive Elastomers as Dynamic Cell Culture Substrata JF - PLoS ONE N2 - Mechanical cues such as extracellular matrix stiffness and movement have a major impact on cell differentiation and function. To replicate these biological features in vitro, soft substrata with tunable elasticity and the possibility for controlled surface translocation are desirable. Here we report on the use of ultra-soft (Young’s modulus <100 kPa) PDMS-based magnetoactive elastomers (MAE) as suitable cell culture substrata. Soft non-viscous PDMS (<18 kPa) is produced using a modified extended crosslinker. MAEs are generated by embedding magnetic microparticles into a soft PDMS matrix. Both substrata yield an elasticity-dependent (14 vs. 100 kPa) modulation of α-smooth muscle actin expression in primary human fibroblasts. To allow for static or dynamic control of MAE material properties, we devise low magnetic field (≈40 mT) stimulation systems compatible with cell-culture environments. Magnetic field-instigated stiffening (14 to 200 kPa) of soft MAE enhances the spreading of primary human fibroblasts and decreases PAX-7 transcription in human mesenchymal stem cells. Pulsatile MAE movements are generated using oscillating magnetic fields and are well tolerated by adherent human fibroblasts. This MAE system provides spatial and temporal control of substratum material characteristics and permits novel designs when used as dynamic cell culture substrata or cell culture-coated actuator in tissue engineering applications or biomedical devices. Y1 - 2013 U6 - https://doi.org/10.1371/journal.pone.0076196 VL - 8 IS - 10 PB - PLOS ER - TY - CHAP A1 - Egersdörfer, Stefan A1 - Zeidler, A. A1 - Wieser, A. A1 - Trompier, F. A1 - Monkman, Gareth J. A1 - Shamonin (Chamonine), Mikhail T1 - A portable accident dosimeter using tooth enamel T2 - Proceedings of the 7th International Symposium on EPR Dosimetry and Applications and the 2nd International Conference on Biodosimetry held at the Uniformed Services University of the Health Sciences, Bethesda, MD, USA, 10-13 July 2006 Y1 - 2006 PB - Pergamon CY - Oxford ER - TY - RPRT A1 - Rabindranath, R. A1 - Böse, Holger A1 - Probst, Jörn A1 - Schlunck, G. A1 - Mayer, Matthias A1 - Forster, Eva A1 - Bentz, Alexander A1 - Shamonin (Chamonine), Mikhail A1 - Monkman, Gareth J. T1 - EAP mit magnetisch steuerbarer Elastizität zur Interaktion mit Bindegewebszellen MagElan BT - Teilvorhaben (HS-Regensburg) "Etablierung eines mechatronischen Systems zur (Magneto) Elastophorese von Bindegewebszellen" ; Schlussbericht ; Verbundprojekt "MagElan" ; Laufzeit des Vorhabens: 01.07.2009 - 30.10.2011 Y1 - 2012 N1 - Förderkennzeichen BMBF 13N10574 CY - Regensburg ER - TY - CHAP A1 - Forster, Eva A1 - Mayer, Matthias A1 - Rabindranath, R. A1 - Bentz, Alexander A1 - Böse, Holger A1 - Shamonin (Chamonine), Mikhail A1 - Monkman, Gareth J. T1 - Surface Control Magneto-Active Polymers (MAP) T2 - EuroEAP 2011, First international conference on Electromechanically Active Polymer (EAP) transducers & artificial muscles, Pisa, 8-9 June N2 - Smart materials change their properties with external energy supply. Besides the known ferro-fluids and Magneto Rheological Fluid (MRF) also the Electro Active Polymer (EAP) and Magneto Rheological Elastomer (MRE) belong to these intelligent materials. The latest generation of magnetic elastomers represents a new class of composite materials. This consists of small magnetized particles which are sized in the micron or even nanometer range that in turn is bounded in a highly elastic rubber matrix. These materials are very often called MRE. Only recently, it has managed to develop these materials even further, so that very soft composite materials with a young?s modulus up to 10 kPa are possible. These soft polymers could be named magneto-active polymers. The combination of polymers with magnetic materials show novel and often enhanced properties. A precisely controllable young?s modulus and hardness, giant and non-homogeneous deformation behavior and rapid response to the magnetic field opens up new possibilities for various applications. Since MAP represent a very new technology, the behavior of these materials as a function of their composition and external conditions so far are not yet sufficiently understood. Therefore, some fundamental studies are necessary. In this paper, the mechanical surface properties are studied using a micro hardness meter. This work shows the possibility to control mechanical properties at the surface of MAP with new developed magnetic systems. Y1 - 2011 ER - TY - JOUR A1 - Bakaev, V. V. A1 - Snarskii, Andrei A. A1 - Shamonin (Chamonine), Mikhail T1 - The permeability and remanent magnetization of a randomly inhomogeneous two-phase medium JF - Technical Physics N2 - A randomly inhomogeneous composite consisting of two, ferromagnetic and nonmagnetic (para-or diamagnetic), phases is considered. The dependence of the effective permeability of the composite on the concentration of the ferromagnetic phase and on the applied magnetic field is found for the case of the negligible hysteresis loop. When the hysteresis loop is appreciable, the remanent magnetization as a function of the ferromagnet concentration is calculated. KW - Magnetic Field KW - Permeability KW - Hysteresis Loop KW - Remanent Magnetization KW - Applied Magnetic Field Y1 - 2002 U6 - https://doi.org/10.1134/1.1435901 VL - 47 SP - 125 EP - 128 PB - Springer ER - TY - JOUR A1 - Snarskii, Andrei A. A1 - Zhenirovskyy, M. I. A1 - Shamonin (Chamonine), Mikhail T1 - The effective properties of macroscopically nonuniform ferromagnetic composites: Theory and numerical experiment JF - Journal of Experimental and Theoretical Physics N2 - Various theoretical models (self-consistent field, local linearization, and percolation theory methods and an analytic solution of the linear problem for an ordered medium) for calculating the magnetostatic properties of two-phase composites containing one ferromagnetic phase were considered. The concentration and field dependences of the effective magnetic permeability were found. A method for determining the coercive force and remanent magnetization as functions of the ferromagnetic phase concentration was suggested. Numerical experiments were performed for composites with a periodic distribution of circular inclusions. The results were compared with the analytically calculated effective magnetic permeability. KW - Numerical Experiment KW - Remanent Magnetization KW - Field Dependence KW - Coercive Force KW - Magnetic Permeability Y1 - 2003 U6 - https://doi.org/10.1134/1.1545385 VL - 96 SP - 66 EP - 77 PB - Springer ER - TY - JOUR A1 - Shamonin (Chamonine), Mikhail A1 - Snarskii, Andrei A. A1 - Zhenirovskyy, M. I. T1 - Effective magnetic permeability of ferromagnetic composites. Theoretical description and comparison with experiment JF - NDT & E International N2 - Two analytical methods based on the so-called local linearization of magnetostatic properties of composite materials with ferromagnetic inclusions in a non-magnetic matrix are described. These methods are applied to the experimental data obtained in Gorkunov et al. [Russ. J. Nondestruct. Test. 3 (2001) 186]. A qualitative agreement is obtained for the concentration values reported in that paper and a quantitative agreement is achieved at slightly different value of concentration. The conclusions are supported by direct numerical modeling. KW - Material characterization KW - Ferromagnetic composites KW - Magnetostatic properties Y1 - 2004 U6 - https://doi.org/10.1016/j.ndteint.2003.08.001 VL - 37 IS - 1 SP - 35 EP - 40 PB - Elsevier ER - TY - JOUR A1 - Filippov, O. A1 - Ringhofer, K. H. A1 - Shamonin (Chamonine), Mikhail A1 - Shamonina, Ekaterina A1 - Kamshilin, A. A. A1 - Nippolainen, E. A1 - Sturman, B. I. T1 - Polarization properties of light-induced scattering in Bi12TiO20 crystals: theory and experiment for diagonal geometry JF - Journal of the Optical Society of America B N2 - Illumination of ac-biased photorefractive Bi12TiO20 crystals with a coherent light beam results in the development of strong nonlinear scattering. Theoretically and experimentally we investigate the angular and polarization characteristics of the scattered light for the diagonal ([1̲1̲1]) optical configuration and different polarization states of the pump. A satisfactory understanding of the observed scattering properties is achieved for most of the cases investigated. Y1 - 2003 U6 - https://doi.org/10.1364/JOSAB.20.000677 VL - 20 IS - 4 SP - 677 EP - 684 PB - Optica Publishing Group ER - TY - JOUR A1 - Lukyanets, S. A1 - Snarskii, Andrei A. A1 - Shamonin (Chamonine), Mikhail A1 - Bakaev, V. V. T1 - Calculation of magnetic leakage field from a surface defect in a linear ferromagnetic material: an analytical approach JF - NDT & E International N2 - A novel analytical approach for calculating the magnetic leakage field from surface defects is proposed and demonstrated for the case of a linear ferromagnetic material. The novelty of the theory is that it relates the distribution of induced magnetic charges to the surface shape. An excellent agreement between the analytical and numerical results is shown. The functional relations between different magnetic field components are discussed. KW - Magnetic methods KW - Flux leakage KW - Mathematical model KW - Defects Y1 - 2003 U6 - https://doi.org/10.1016/S0963-8695(02)00071-3 VL - 36 IS - 1 SP - 51 EP - 55 PB - Elsevier ER - TY - JOUR A1 - Snarskii, Andrei A. A1 - Shamonin (Chamonine), Mikhail A1 - Zhenirovskyy, M. I. T1 - Effective properties of macroscopically non-uniform ferromagnetic composite materials BT - Theory and numerical experiment JF - Zhurnal Eksperimental'noj i Teoreticheskoj Fiziki - Journal of Experimental and Theoretical Physics (JETP) Y1 - 2003 VL - 123 IS - 1 SP - 79 EP - 92 PB - Akademija Nauk SSSR CY - Moscow ER - TY - JOUR A1 - Snarskii, Andrei A. A1 - Shamonin (Chamonine), Mikhail A1 - Zhenirovskyy, M. I. A1 - Trautner, Ralph T1 - Effect of disorder on the conductivity of two-phase strongly inhomogeneous highly filled composites JF - Theoretical and Mathematical Physics N2 - The effect of the “stir” of a structure (small deviations from strict periodicity) on effective conductivity is considered. For determinate and random deviations, concentration and field dependences of the effective conductivity are found. Numerical experiments with determinate deviations are carried out for the cases of linear (with respect to the field) inclusions embedded in both a linear and nonlinear matrix. The numerical results are compared with the effective conductivity calculated analytically. KW - Small Deviation KW - Numerical Experiment KW - Field Dependence KW - Effective Conductivity KW - Random Deviation Y1 - 2005 U6 - https://doi.org/10.1134/1.1854818 VL - 50 SP - 11 EP - 18 PB - Springer ER - TY - JOUR A1 - Kriegl, Raphael A1 - Kravanja, Gaia A1 - Hribar, Luka A1 - Čoga, Lucija A1 - Drevenšek-Olenik, Irena A1 - Jezeršek, Matija A1 - Kalin, Mitjan A1 - Shamonin (Chamonine), Mikhail T1 - Microstructured Magnetoactive Elastomers for Switchable Wettability JF - Polymers N2 - We demonstrate the control of wettability of non-structured and microstructured magnetoactive elastomers (MAEs) by magnetic field. The synthesized composite materials have a concentration of carbonyl iron particles of 75 wt.% (≈27 vol.%) and three different stiffnesses of the elastomer matrix. A new method of fabrication of MAE coatings on plastic substrates is presented, which allows one to enhance the response of the apparent contact angle to the magnetic field by exposing the particle-enriched side of MAEs to water. A magnetic field is not applied during crosslinking. The highest variation of the contact angle from (113 ± 1)° in zero field up to (156 ± 2)° at about 400 mT is achieved in the MAE sample with the softest matrix. Several lamellar and pillared MAE structures are fabricated by laser micromachining. The lateral dimension of surface structures is about 50 µm and the depth varies between 3 µm and 60 µm. A systematic investigation of the effects of parameters of laser processing (laser power and the number of passages of the laser beam) on the wetting behavior of these structures in the absence and presence of a magnetic field is performed. In particular, strong anisotropy of the wetting behavior of lamellar structures is observed. The results are qualitatively discussed in the framework of the Wenzel and Cassie-Baxter models. Finally, directions of further research on magnetically controlled wettability of microstructured MAE surfaces are outlined. The obtained results may be useful for the development of magnetically controlled smart surfaces for droplet-based microfluidics. Y1 - 2022 U6 - https://doi.org/10.3390/polym14183883 N1 - Corresponding authors: Raphael Kriegl und Mikhail Shamonin VL - 14 IS - 18 SP - 1 EP - 21 PB - MDPI ER - TY - JOUR A1 - Jezeršek, Matija A1 - Kriegl, Raphael A1 - Kravanja, Gaia A1 - Hribar, Luka A1 - Drevenšek-Olenik, Irena A1 - Unold, Heiko A1 - Shamonin (Chamonine), Mikhail T1 - Control of Droplet Impact through Magnetic Actuation of Surface Microstructures JF - Advanced Materials Interfaces N2 - An effective method for on-demand control over the impact dynamics of droplets on a magnetoresponsive surface is reported. The surface is comprised of micrometer-sized lamellas from a magnetoactive elastomer on a copper substrate. The surface itself is fabricated using laser micromachining. The orientation of the lamellae is switched from edge-on (orthogonal to the surface) to face-on (parallel to the surface) by changing the direction of a moderate (<250 mT) magnetic field. This simple actuation technique can significantly change the critical velocities of droplet rebound, deposition, and splashing. Rebound and deposition regimes can be switched up to Weber number We < 13 ± 3, while deposition and splashing can be switched in the range of 32 < We < 52. Because a permanent magnet is used, no permanent power supply is required for maintaining the particular regime of droplet impact. The presented technology is highly flexible and enables selective fabrication and actuation of microstructures on complex devices. It has great potential for applications in soft robotics, microfluidics, and advanced thermal management. Y1 - 2023 U6 - https://doi.org/10.1002/admi.202202471 VL - 10 IS - 11 PB - Wiley ER - TY - JOUR A1 - Sorokin, Vladislav V. A1 - Stepanov, Gennady V. A1 - Shamonin (Chamonine), Mikhail A1 - Monkman, Gareth J. A1 - Khokhlov, Alexei R. A1 - Kramarenko, Elena Yu T1 - Hysteresis of the viscoelastic properties and the normal force in magnetically and mechanically soft magnetoactive elastomers: Effects of filler composition, strain amplitude and magnetic field JF - Polymer N2 - Hysteresis in dynamic modulus, loss factor and normal forces of magnetoactive elastomers (MAEs) comprising various proportions of small (3-5 mu m) and large (50-60 mu m) ferromagnetic particles are experimentally studied using dynamic torsion performed at a fixed oscillation frequency in varying DC magnetic fields. It is shown that hysteresis is a characteristic feature of MAEs observed both under increasing/decreasing magnetic field strength and increasing/decreasing strain amplitude. This hysteresis is attributed to the specific rearrangement of the magnetic filler network under simultaneously applied magnetic field and shear deformation. Rheological properties of the magnetic filler network formed in the magnetic field and, therefore, the rheological properties of MAEs depend strongly on the filler composition and the magnetic field magnitude. Larger magnetic particles and higher magnetic fields provide stronger magnetic networks. Both factors result in the extension of the linear viscoelastic regime to larger strain amplitudes and lead to higher values of shear storage and loss moduli. It is found that the hysteresis width maximises at an intermediate magnetic field where it is attributed to the balance between elastic and magnetic particle interactions. This is apparently where the most significant restructuring of the magnetic network occurs. The hysteresis width decreases with increasing fraction of large particles in the magnetic filler. The loss factor grows significantly when the magnetic network is physically broken by large strains gamma > 1%. A huge (more than one order of magnitude) increase of normal force at maximum magnetic field strengths is observed. It is predicted that any physical quantity depending on the internal structuring of the magnetic filler should demonstrate hysteresis either with a changing magnetic field and constant deformation amplitude or under variable deformation in a constant magnetic field. (C) 2015 Elsevier Ltd. All rights reserved. KW - BEHAVIOR KW - COMPRESSION KW - Dynamic modulus KW - GELS KW - hysteresis KW - Magnetorheological elastomers KW - magnetostriction KW - MODULUS KW - PARTICLES KW - POLYMER COMPOSITES KW - shear Y1 - 2015 U6 - https://doi.org/10.1016/j.polymer.2015.08.040 VL - 76 SP - 191 EP - 202 PB - Elsevier ER - TY - JOUR A1 - Sorokin, Vladislav V. A1 - Ecker, Eva A1 - Stepanov, Gennady V. A1 - Shamonin (Chamonine), Mikhail A1 - Monkman, Gareth J. A1 - Kramarenko, Elena Yu A1 - Khokhlov, Alexei R. T1 - Experimental study of the magnetic field enhanced Payne effect in magnetorheological elastomers JF - Soft Matter N2 - The dynamic modulus and the loss factor of magnetorheological elastomers (MREs) of various compositions and anisotropies are studied by dynamic torsion oscillations performed in the absence and in the presence of an external magnetic field. The emphasis is on the Payne effect, i.e. the dependence of the elastomer magnetorheological characteristics on the strain amplitude and their evolution with cyclically increasing and decreasing strain amplitudes. MREs are based on two silicone matrices differing in storage modulus (soft, G' similar to 10(3) Pa, and hard, G' similar to 10(4) Pa, matrices). For each matrix, the concentration of carbonyl iron particles with diameters of 3-5 mu m was equal to 70 and 82 mass% (22 and 35 vol%, respectively) in the composite material. Samples for each filler content, isotropic and aligned-particles, are investigated. It is found that the Payne effect significantly increases in the presence of an external magnetic field and varies with the cyclical loading which reaches saturation after several cycles. The results are interpreted as the processes of formation-destruction-reformation of the internal filler structure under the simultaneously applied mechanical force and magnetic field. Impacts of matrix elasticity and magnetic interactions on the filler alignment are elucidated. KW - BEHAVIOR KW - CARRAGEENAN KW - DAMPERS KW - MODEL KW - SEALS KW - SENSITIVE ELASTOMERS KW - Shear modulus KW - VISCOELASTIC PROPERTIES KW - WIDE-RANGE MODULATION Y1 - 2014 U6 - https://doi.org/10.1039/c4sm01738b VL - 10 IS - 43 SP - 8765 EP - 8776 PB - ROYAL Society of CHEMISTRY ER - TY - JOUR A1 - Kriegl, Raphael A1 - Kovalev, Alexander A1 - Shamonin (Chamonine), Mikhail A1 - Gorb, Stanislav T1 - Tunable contact angle hysteresis on compliant magnetoactive elastomers JF - Extreme Mechanics Letters N2 - It is shown that the advancing (ACA) and receding (RCA) contact angles of water on extremely soft (shear modulus of the order of 10 kPa) magnetoactive elastomer (MAE) films significantly depend on the applied magnetic field. The difference between these angles, known as the contact angle hysteresis, is examined. The roles of the filler concentration and material softness are elaborated. The highest change in the contact angle hysteresis (CAH) from 34° in the absence of magnetic field to 76° in a magnetic field of 0.4 T is achieved for the softest sample with the lowest mass fraction of iron particles (70 wt%). The dependence of the CAH on magnetization history (“magnetic hysteresis”) is observed. This magnetic hysteresis is clearly pronounced for the ACA and has little effect on the RCA. Magnetic field-induced changes of the surface roughness exhibit qualitatively the same hysteresis behavior with regard to the external magnetic field as the ACA. The results are promising for the development of smart surfaces for applications where the dynamic wetting has to be controlled. KW - Magnetoactive elastomers KW - Dynamic wetting KW - Magnetic hysteresis KW - Contact angle hysteresis Y1 - 2023 U6 - https://doi.org/10.1016/j.eml.2023.102049 SN - 2352-4316 VL - 63 PB - Elsevier ER - TY - CHAP A1 - Forster, Eva A1 - Rabindranath, R. A1 - Mayer, M. A1 - Bentz, Alexander A1 - Böse, Holger A1 - Shamonin (Chamonine), Mikhail A1 - Monkman, Gareth J. T1 - Characterization of ultra soft Magneto-Active Polymers (MAPs) T2 - Conference proceedings / INDUCTICA 2011, Berlin, Germany, 24 - 26 May Y1 - 2011 ER - TY - JOUR A1 - Saveliev, Dmitry V. A1 - Glavan, Gašper A1 - Belan, Viktoria O. A1 - Belyaeva, Inna A. A1 - Fetisov, Leonid Y. A1 - Shamonin (Chamonine), Mikhail T1 - Resonant Magnetoelectric Effect at Low Frequencies in Layered Polymeric Cantilevers Containing a Magnetoactive Elastomer JF - Applied Sciences N2 - In this work, the resonance enhancement of magnetoelectric (ME) coupling at the two lowest bending resonance frequencies was investigated in layered cantilever structures comprising a magnetoactive elastomer (MAE) slab and a commercially available piezoelectric polymer multilayer. A cantilever was fixed at one end in the horizontal plane and the magnetic field was applied horizontally. Five composite structures, each containing an MAE layer of different thicknesses from 0.85 to 4 mm, were fabricated. The fundamental bending resonance frequency in the absence of a magnetic field varied between roughly 23 and 55 Hz. It decreased with the increasing thickness of the MAE layer, which was explained by a simple theory. The largest ME voltage coefficient of about 7.85 V/A was measured in a sample where the thickness of the MAE layer was ≈2 mm. A significant increase in the bending resonance frequencies in the applied DC magnetic field of 240 kA/m up to 200% was observed. The results were compared with alternative designs for layered multiferroic structures. Directions for future research were also discussed. KW - flexible composite KW - low frequency KW - magnetoactive elastomer KW - magnetoelectric effect KW - piezoelectric polymer Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-30637 N1 - corresponding authors: Dmitry V. Saveliev and Mikhail Shamonin VL - 12 IS - 4 SP - 1 EP - 13 PB - MPDI ER - TY - JOUR A1 - Glavan, Gašper A1 - Kettl, Wolfgang A1 - Brunhuber, Alexander A1 - Shamonin (Chamonine), Mikhail A1 - Drevenšek-Olenik, Irena T1 - Effect of Material Composition on Tunable Surface Roughness of Magnetoactive Elastomers JF - Polymers N2 - We investigated magnetic-field-induced modifications of the surface roughness of magnetoactive elastomers (MAEs) with four material compositions incorporating two concentrations of ferromagnetic microparticles (70 wt% and 80 wt%) and exhibiting two shear storage moduli of the resulting composite material (about 10 kPa and 30 kPa). The analysis was primarily based on spread optical reflection measurements. The surfaces of all four materials were found to be very smooth in the absence of magnetic field (RMS roughness below 50 nm). A maximal field-induced roughness modification (approximately 1 m/T) was observed for the softer material with the lower filler concentration, and a minimal modification (less than 50 nm/T) was observed for the harder material with the higher filler concentration. All four materials showed a significant decrease in the total optical reflectivity with an increasing magnetic field as well. This effect is attributed to the existence of a distinct surface layer that is depleted of microparticles in the absence of a magnetic field but becomes filled with particles in the presence of the field. We analyzed the temporal response of the reflective properties to the switching on and off of the magnetic field and found switching-on response times of around 0.1 s and switching-off response times in the range of 0.3-0.6 s. These observations provide new insight into the magnetic-field-induced surface restructuring of MAEs and may be useful for the development of magnetically reconfigurable elastomeric optical surfaces. KW - magnetically tunable surface reflectivity KW - magnetically tunable surface roughness KW - magnetorheological elastomer KW - magnetorheological polymers KW - surface properties Y1 - 2019 U6 - https://doi.org/10.3390/polym11040594 N1 - Corresponding author: Gašper Glavan VL - 11 IS - 4 SP - 1 EP - 13 PB - MDPI CY - Basel ER - TY - JOUR A1 - Glavan, Gašper A1 - Salamon, Peter A1 - Belyaeva, Inna A. A1 - Shamonin (Chamonine), Mikhail A1 - Drevensek-Olenik, Irena T1 - Tunable surface roughness and wettability of a soft magnetoactive elastomer JF - Journal of applied polymer science N2 - Surface topographical modifications of a soft magnetoactive elastomer (MAE) in response to variable applied magnetic field are investigated. The analysis is performed in situ and is based on optical microscopy, spread optical reflection and optical profilometry measurements. Optical profilometry analysis shows that the responsivity of magnetic field-induced surface roughness with respect to external magnetic field is in the range of 1 mu m/T. A significant hysteresis of surface modifications takes place for increasing and decreasing fields. Investigations of shape of sessile water droplets deposited on the MAE surface reveal that field-induced topographical modifications affect the contact angle of water at the surface. This effect is reversible and the responsivity to magnetic field is in the range of 20 degrees/T. Despite the increased surface roughness, the apparent contact angle decreases with increasing field, which is attributed to the field-induced protrusion of hydrophilic microparticles from the surface layer. KW - CONTACT KW - EVAPORATION KW - FORCE KW - hydrophobic polymers KW - MAGNETIC-MATERIALS KW - magnetism and magnetic properties KW - optical properties KW - STIMULI-RESPONSIVE SURFACES KW - stimuli-sensitive polymers KW - structure-property relationships Y1 - 2018 U6 - https://doi.org/10.1002/app.46221 VL - 135 IS - 18 PB - Wiley ER - TY - JOUR A1 - Sydoruk, O. A1 - Shamonin (Chamonine), Mikhail A1 - Radkovskaya, A. A1 - Zhuromskyy, O. A1 - Shamonina, Ekaterina A1 - Trautner, Ralph A1 - Stevens, C. J. A1 - Faulkner, Grahame A1 - Edwards, David J. A1 - Solymar, L. T1 - Mechanism of subwavelength imaging with bilayered magnetic metamaterials: Theory and experiment JF - Journal of Applied Physics N2 - We present a theoretical and experimental study of a bilayered metamaterial structure for subwavelength imaging of magnetic field. The simplest version of such a structure consists of one or two linear arrays of capacitively loaded split pipe resonators. Its subwavelength physics is governed by strongly anisotropic magnetic coupling between individual resonators and by propagation of magnetoinductive waves with wavelength much shorter than the wavelength of the electromagnetic radiation in free space. It is shown that magnetoinductive waves propagating in the lateral direction are undesirable because they spread the image. Good subwavelength imaging is achieved when, due to the strong interlayer coupling, a stop band in the vicinity of the resonant frequency appears in the dispersion characteristics. The imaging properties of the single and double lens are compared and it is shown that the double lens has a superior performance. Excellent agreement is obtained between experimental and theoretical results for the magnetic field in the image plane in the operation frequency range of 30–60 MHz. It is shown that the same mechanism is responsible for image formation using bilayered planar metamaterial structures and a design of such a lens comprising two planar layers with a total of 542 elements is provided. The conclusions are not restricted to the radio frequency region because the elements can be scaled down. Y1 - 2007 U6 - https://doi.org/10.1063/1.2714782 VL - 101 IS - 7 PB - AIP ER - TY - JOUR A1 - Radkovskaya, A. A1 - Sydoruk, O. A1 - Shamonin (Chamonine), Mikhail A1 - Shamonina, Ekaterina A1 - Stevens, C. J. A1 - Faulkner, Grahame A1 - Edwards, David J. A1 - Solymar, L. T1 - Experimental study of a bi-periodic magnetoinductive waveguide: comparison with theory JF - IET Microwaves, Antennas & Propagation N2 - Magnetoinductive waves propagating along a line consisting of two kinds of metamaterial elements are studied. Both elements are made up by the same metallic loop but are loaded by different capacitors resulting in different resonant frequencies. The dispersion characteristics are derived from phase and amplitude measurements for the cases when the line consists of (i) identical elements and (ii) of alternating elements. Both planar (elements in the same plane as the axis of the line) and axial (elements perpendicular to the axis of the line) configurations are investigated. It is shown that in the bi-periodic arrangement of the elements, the dispersion curves have a forward wave in the lower frequency branch and a backward wave in the upper frequency branch independent of the configuration whether it is planar or axial. Comparisons between theoretical and experimental results show good agreement. KW - magnetic materials KW - metamaterials KW - wave propagation KW - dispersion (wave) KW - waveguides Y1 - 2007 U6 - https://doi.org/10.1049/iet-map:20050289 SN - 1751-8733 VL - 1 IS - 1 SP - 80 EP - 83 PB - IET ER - TY - JOUR A1 - Radkovskaya, A. A1 - Sydoruk, O. A1 - Shamonin (Chamonine), Mikhail A1 - Stevens, C. J. A1 - Faulkner, Grahame A1 - Edwards, David J. A1 - Shamonina, Ekaterina A1 - Solymar, L. T1 - Transmission properties of two shifted magnetoinductive waveguides JF - Microwave and Optical Technology Letters N2 - Transmission properties of magnetoinductive waves propagating in two coupled one-dimensional metamaterial arrays are studied both experimentally and theoretically for the case when one of the arrays is shifted relative to the other one. Two different kinds of resonant metamaterial elements, split-pipe and spiral resonators, are investigated in the frequency bands centred at 46.2 and 586 MHz, respectively. It is shown that within a certain frequency range close to the resonant frequencies the transmission is strongly dependent on the shift. Theoretical calculations based on the impedance matrix show good agreement with the experimental results Y1 - 2007 U6 - https://doi.org/10.1002/mop.22344 VL - 49 IS - 5 SP - 997 EP - 1230 PB - Wiley ER - TY - CHAP A1 - Mayer, M. A1 - Forster, Eva A1 - Rabindranath, R. A1 - Bentz, Alexander A1 - Böse, Holger A1 - Shamonin (Chamonine), Mikhail A1 - Monkman, Gareth J. T1 - Highly compliant Magneto-Active Polymers (MAPs) T2 - Actuator'11, Bremen, May 2011 Y1 - 2011 ER - TY - JOUR A1 - Hörner, Eduard A1 - Krykanov, Ivan M. A1 - Chashin, Dmitry V. A1 - Fetisov, Yury K. A1 - Fetisov, Leonid Y. A1 - Shamonin (Chamonine), Mikhail T1 - Magnetoelectric characteristics of cobalt-iron alloy–lead zirconate titanate bilayer planar structures JF - International Journal of Materials Research N2 - The characteristics of both direct and converse magnetoelectric (ME) interactions in bilayer composite structures comprising layers of a commercially available magnetostrictive permendur CoFe alloy and different piezoelectric PZT ceramics are investigated in detail by the method of harmonic field modulation. It is shown that, given the optimum DC magnetic bias field, a high piezomagnetic coefficient in the alloy leads to increased efficiency of ME interactions. The resonant behavior of frequency dependencies of the magnetoelectric voltage is explained by excitation of bending and planar mechanical oscillations in the structures. The results are of interest for developing highly sensitive AC magnetic field sensors and magnetoelectric transducers for energy harvesting from mechanical vibrations. KW - Composite materials KW - Magnetostriction KW - Piezoelectricity KW - Magnetically ordered materials KW - Magnetoelectric effect Y1 - 2012 U6 - https://doi.org/10.3139/146.110776 VL - 103 IS - 11 PB - De Gruyter ER - TY - JOUR A1 - Glavan, Gašper A1 - Belyaeva, Inna A. A1 - Shamonin (Chamonine), Mikhail T1 - Multiferroic Cantilevers Containing a Magnetoactive Elastomer: Magnetoelectric Response to Low-Frequency Magnetic Fields of Triangular and Sinusoidal Waveform JF - Sensors N2 - In this work, multiferroic cantilevers comprise a layer of a magnetoactive elastomer (MAE) and a commercially available piezoelectric polymer-based vibration sensor. The structures are fixed at one end in the horizontal plane and the magnetic field is applied vertically. First, the magnetoelectric (ME) response to uniform, triangle-wave magnetic fields with five different slew rates is investigated experimentally. Time and field dependences of the generated voltage, electric charge, and observed mechanical deflection are obtained and compared for four different thicknesses of the MAE layer. The ME responses to triangular and sinusoidal wave excitations are examined in contrast. Second, the ME response at low frequencies (≤3 Hz) is studied by the standard method of harmonic magnetic field modulation. The highest ME coupling coefficient is observed in the bias magnetic field strength of ≈73 kA/m and it is estimated to be about 3.3 ns/m (ME voltage coefficient ≈ 25 V/A) at theoretically vanishing modulation frequency (f→0 Hz). Presented results demonstrate that the investigated heterostructures are promising for applications as magnetic-field sensors and energy harvesting devices. KW - magnetoactive elastomer KW - piezoelectric polymer KW - multilayer cantilever KW - direct magnetoelectric effect KW - magnetic field sensing Y1 - 2022 U6 - https://doi.org/10.3390/s22103791 N1 - Corresponding authors: Gašper Glavan und Mikhail Shamonin VL - 22 IS - 10 SP - 1 EP - 17 PB - MDPI CY - Basel ER - TY - JOUR A1 - Lovšin, Matija A1 - Brandl, Dominik A1 - Glavan, Gašper A1 - Belyaeva, Inna A. A1 - Cmok, Luka A1 - Coga, Lucija A1 - Kalin, Mitjan A1 - Shamonin (Chamonine), Mikhail A1 - Drevenšek-Olenik, Irena T1 - Reconfigurable Surface Micropatterns Based on the Magnetic Field-Induced Shape Memory Effect in Magnetoactive Elastomers JF - Polymers N2 - A surface relief grating with a period of 30 mu m is embossed onto the surface of magnetoactive elastomer (MAE) samples in the presence of a moderate magnetic field of about 180 mT. The grating, which is represented as a set of parallel stripes with two different amplitude reflectivity coefficients, is detected via diffraction of a laser beam in the reflection configuration. Due to the magnetic-field-induced plasticity effect, the grating persists on the MAE surface for at least 90 h if the magnetic field remains present. When the magnetic field is removed, the diffraction efficiency vanishes in a few minutes. The described effect is much more pronounced in MAE samples with larger content of iron filler (80 wt%) than in the samples with lower content of iron filler (70 wt%). A simple theoretical model is proposed to describe the observed dependence of the diffraction efficiency on the applied magnetic field. Possible applications of MAEs as magnetically reconfigurable diffractive optical elements are discussed. It is proposed that the described experimental method can be used as a convenient tool for investigations of the dynamics of magnetically induced plasticity of MAEs on the micrometer scale. KW - ADHESION KW - friction KW - magnetoactive elastomers KW - magnetorheological elastomer KW - optical diffraction KW - shape memory effect KW - surface microstructuring KW - TEMPERATURE Y1 - 2021 U6 - https://doi.org/10.3390/polym13244422 VL - 13 IS - 24 PB - MDPI ER - TY - CHAP A1 - Dötsch, Horst A1 - Holthaus, C. A1 - Trifonov, A. A1 - Klank, M. A1 - Hagedorn, Oliver A1 - Shamonin (Chamonine), Mikhail A1 - Schützmann, J. T1 - Application of Magnetic Garnet Films for Magnetooptical Imaging of Magnetic Field Distributions T2 - MRS Online Proceedings Library N2 - Rare-earth iron garnet films of high quality can be grown by liquid phase epitaxy on paramagnetic substrates of gadolinium galliumgarnet. Such films are currently used for imaging of the spatial distribution of magnetic fields. This application is based on the Faraday rotation which can strongly be enhanced by bismuth incorporation. The physical properties of the films can be controlled by the chemical composition, the growth conditions and the crystallographic orientation. The sensor properties like sensitivity, dynamic range, signal linearity and unambiguity must be optimized according to the application desired. These properties, however, are not independent of each other. In addition, they strongly depend on the optical wavelength. Thus, it is necessary to find compromises. The influence of Faraday rotation, Faraday ellipticity, optical absorption, magnetic anisotropies and film thickness on the performance of a magnetooptical indicator film is investigated. Based on the swing of the photoresponse, a new optimization process is introduced. The process is experimentally verified and application examples are demonstrated. Furthermore, two methods are presented to enhance the sensitivity of magnetooptical sensors. Using specific crystallographic orientations, an easy plane of magnetization can be induced which is inclined with respect to the film plane. If the magnetization lies in this plane a very high sensitivity is achieved. The dependence of the geometrical orientation of the easy plane on the growth direction is calculated and the sensitivity and dynamic range are derived. Experimental results of a [112] oriented garnet film are in good agreement with calculations. Garnet films which are magnetized along the film normal due to a strong induced uniaxial anisotropy support magnetic domains. If the collapse field perpendicular to the film plane is small, such films can be used as very sensitive indicator films. Such films are easier to prepare than sensitive in-plane films. However, the spatial resolution is limited by the size of the domains. This disadvantage can be avoided by applying a bias field in the film plane. Directly at the in-plane collapse field the sensor film is in-plane magnetized yielding high spatial resolution at still high sensitivity. The variation of magnetooptical images with in-plane induction is demonstrated. Experimental results are in agreement with calculations. Y1 - 2004 U6 - https://doi.org/10.1557/PROC-834-J6.1 SP - 18 EP - 29 PB - Springer ER - TY - JOUR A1 - Klank, M. A1 - Hagedorn, Oliver A1 - Holthaus, C. A1 - Shamonin (Chamonine), Mikhail A1 - Dötsch, Horst T1 - Characterization and optimization of magnetic garnet films for magneto-optical visualization of magnetic field distributions JF - NDT & E International N2 - Rare-earth iron garnet films with in-plane anisotropy grown on (111)-oriented substrates can be used as magneto-optical indicator films for visualization of magnetic leakage fields in nondestructive evaluation. The influence of Faraday rotation, Faraday ellipticity, absorption and film thickness on the performance of a magneto-optical indicator film is investigated. A new optimization method is introduced and compared with the method of contrast optimization. The theory is experimentally verified and an application example is presented. KW - Magneto-optics KW - Imaging KW - Magnetic flux leakage KW - Garnet films Y1 - 2003 U6 - https://doi.org/10.1016/S0963-8695(03)00012-4 VL - 36 IS - 6 SP - 375 EP - 381 PB - Elsevier ER - TY - JOUR A1 - Glavan, Gašper A1 - Belyaeva, Inna A. A1 - Drevenšek-Olenik, Irena A1 - Shamonin (Chamonine), Mikhail T1 - Experimental study of longitudinal, transverse and volume strains of magnetoactive elastomeric cylinders in uniform magnetic fields JF - Journal of Magnetism and Magnetic Materials N2 - Magnetoactive elastomers (MAEs) are promising materials for realization of magnetic field-controlled soft actuators. Herein, a systematic investigation of magnetic field-induced macroscopic deformations of soft MAE cylinders with a diameter of 15 mm in uniform quasi-static magnetic fields directed parallel to the cylinder’s axis is reported. The measurements were based on image processing. Thirty-six MAE samples differing in the weight fraction of the iron filler (70 wt%, 75 wt% and 80 wt%), alignment of filling particles, and the aspect ratio (0.2, 0.4, 0.6, 0.8, 1.0 and 1.2) were fabricated. MAE cylinders exhibited high relative change in height (up to 35% in the field of 485 kA/m) and lateral contraction. The dependence of the maximum extensional strain on the aspect ratio was obtained and compared with theoretical considerations. A concave dent was formed on the free circular base in magnetic fields. This concavity was characterized experimentally. A significant volumetric strain of the order of magnitude of 10% was calculated in MAEs for the first time. In consequently repeated magnetization cycles, the remanent extensional strain significantly increased after each cycle. The results are qualitatively discussed in the framework of the modern views on the magnetically induced macroscopic deformations of MAEs. The directions of further research are outlined. Y1 - 2023 U6 - https://doi.org/10.1016/j.jmmm.2023.170826 SN - 0304-8853 VL - 579 PB - Elsevier ER - TY - JOUR A1 - Lohmeyer, M. A1 - Shamonin (Chamonine), Mikhail A1 - Hertel, P. T1 - Boundary conditions for the finite difference beam propagation method based on plane wave solutions of the Fresnel equation JF - IEEE Journal of Quantum Electronics N2 - Each particular implementation of the beam propagation method (BPM) requires a special procedure allowing for radiation to leave the computational window. We propose a new approach to constructing the finite difference schemes of the BPM at the boundary of the computational window. These schemes are independent of the computed fields and allow for a similar treatment of both interior and boundary points. The new approach can be further improved by correcting the field values at the boundary points according to Hadley's method. The algorithm is easy to implement for both two- and three-dimensional structures. The new method considerably reduces computation times because the propagation matrices remain constant in longitudinally invariant sections, thus avoiding repeated LU-decompositions. The basic idea-establishing the finite difference scheme such that locally exact, approximate, or plausible solutions are recovered-may be of interest for other efforts to solve partial differential equations by the finite difference method. KW - Boundary conditions KW - Finite difference methods KW - Optical propagation KW - Matrix decomposition KW - Computational modeling KW - Refractive index KW - Maxwell equations KW - Sparse matrices KW - Partial differential equations KW - Shape Y1 - 1997 U6 - https://doi.org/10.1109/3.552269 SN - 0018-9197 VL - 33 IS - 2 SP - 279 EP - 286 ER - TY - JOUR A1 - Shamonin (Chamonine), Mikhail A1 - Lohmeyer, M. A1 - Hertel, P. T1 - Analysis of power-dependent switching between radiatively coupled planar waveguides JF - Journal of Lightwave Technology N2 - Effective coupling between two remote optical waveguides without branching sections can be achieved in a three-guide system with multimode central waveguide. We investigate the nonlinear power switching of c.w. laser radiation by such radiatively coupled waveguides. It is shown that effective all-optical switches with spatially well separated input/output channels can be realized although the influence of multimode interference on the switching characteristics becomes more pronounced for increasing thickness of the central guide. Different coupling regimes are specified, and the changes in switching characteristics during the transformation from one regime to another is studied. Numerical calculations for the critical power are compared with an approximate analytical expression. It is also shown that, at a moderate input power, a small number of modes determines the switching behavior. KW - Electromagnetic coupling KW - Planar waveguide KW - Optical waveguides KW - Nonlinear optics KW - Optical coupling KW - Optical surface waves KW - Optical refraction KW - Optical variables control KW - Refractive index KW - Optical switches Y1 - 1997 UR - 1558-2213 U6 - https://doi.org/10.1109/50.588671 VL - 15 IS - 6 SP - 983 EP - 989 PB - IEEE CY - New York ER - TY - JOUR A1 - Lohmeyer, M. A1 - Shamonin (Chamonine), Mikhail A1 - Bahlmann, N. A1 - Hertel, P. A1 - Dotsch, H. T1 - Radiatively Coupled Waveguide Concept for an Integrated Magneto-Optic Circulator JF - MRS Online Proceedings Library N2 - Three-guide couplers with multimode central waveguides allow for remote coupling between optical channels. A simple three mode approximation turns out to be sufficient for the description of the main features of the power transfer behavior. The specific form of the relevant modes suggests the design of integrated optical isolators and circulators based on magnetic garnet materials. These novel devices are superior to conventional nonreciprocal couplers with respect to the total length and admissible fabrication tolerances. We characterize the isolation performance and the transmission loss for the proposed devices by propagating mode simulations and estimate the influence of geometry parameter deviations. Y1 - 1998 U6 - https://doi.org/10.1557/PROC-517-519 SN - 1946-4274 IS - 517 SP - 519 EP - 524 ER - TY - JOUR A1 - Shamonin (Chamonine), Mikhail A1 - Lohmeyer, M. A1 - Hertel, P. T1 - Directional coupler based on radiatively coupled waveguides JF - Applied optics (Appl. Opt.) N2 - We investigate a system of two waveguides with leaky modes sharing a common substrate (radiatively coupled waveguides). The main advantage of such a system is the possibility of remote coupling. A perturbation theory is developed for both TE and TM polarization. Numerical calculations of dispersion curves and of the coupling length allow us to determine the limitations of the perturbation theory. We study the influence of multimode interference on the process of beating by considering the propagation of a given initial field. Finally, we propose a new design for an effective, integrated optical TE-TM polarization splitter. Y1 - 1997 UR - https://opg.optica.org/ao/abstract.cfm?URI=ao-36-3-635 U6 - https://doi.org/10.1364/ao.36.000635 VL - 36 IS - 3 SP - 635 EP - 641 ER - TY - JOUR A1 - Snarskii, Andrei A. A1 - Shamonin (Chamonine), Mikhail A1 - Yuskevich, Pavel T1 - Effect of magnetic-field-induced restructuring on the elastic properties of magnetoactive elastomers JF - Journal of Magnetism and Magnetic Materials N2 - Composite materials where magnetic micrometer-sized particles are embedded into a compliant polymer matrix are known as magnetorheological (or magnetoactive) elastomers (MAEs). They are distinguished by huge variations in their physical properties, when in a magnetic field, which is commonly attributed to the restructuring of the filler. The process of the magnetic-field-induced restructuring in a magnetorheological elastomer is interpreted as progression towards percolation. Such a physical model was previously used to explain the dependence of the magnetic permeability and dielectric permittivity of MAEs on the magnetic field strength. Based on this hypothesis, the magnetorheological effect in MAEs is considered theoretically. The theoretical approach is built upon a self-consistent effective-medium theory for the elastic properties, extended to the variable (field dependent) percolation threshold. The proposed model allows one to describe the large variations (over several orders of magnitude) of the effective elastic moduli of these composite materials, known as the giant magnetorheological (MR) and field-stiffening effects. The existence of a giant magnetic Poisson effect is predicted. The relation of the proposed model to the existing theories of the MR effect in MAEs is discussed. The results can be useful for applications of MAEs in magnetic-field-controlled vibration dampers and isolators. Y1 - 2021 U6 - https://doi.org/10.1016/j.jmmm.2020.167392 IS - 517, January PB - Elsevier ER - TY - JOUR A1 - Lohmeyer, Manfred A1 - Shamonin (Chamonine), Mikhail A1 - Hertel, Peter T1 - Integrated optical circulator based on radiatively coupled magneto-optic waveguides JF - Optical Engineering N2 - In a three-guide coupler with multimode central waveguide, more than two modes of the entire structure participate in the coupling between the outer waveguides. Using a three-mode approximation we found simple conditions for complete power transfer between the outer waveguides: the device length has to match certain multiples of the con- ventionally defined coupling length. The specific form of the relevant modes allows us to design a magneto-optic isolator or circulator with significantly reduced device length (as compared to the conventional nonreciprocal coupler). The performance of the proposed devices is simulated by propagating-mode calculations. Estimates for admissible fabrication tolerances for the layer thicknesses are presented. KW - integrated optics KW - magneto-optic circulator KW - magneto-optic isolator KW - radiatively coupled waveguides KW - three-guide coupler Y1 - 1997 U6 - https://doi.org/10.1117/1.601255 VL - 36 IS - 3 SP - 889 EP - 895 PB - SPIE ER - TY - GEN A1 - Kriegl, Raphael A1 - Kravanja, Gaia A1 - Hribar, Luka A1 - Jezeršek, Matija A1 - Drevenšek-Olenik, Irena A1 - Shamonin (Chamonine), Mikhail T1 - Characterization of Wetting Properties of Magnetoactive Elastomer Surfaces T2 - Proceedings of the ASME Conference on Smart Materials, Adaptive Structures and Intelligent Systems (SMASIS) - 2023, September 11–13, 2023 Austin, Texas, USA N2 - Commercially available contact angle (CA) measuring devices usually do not allow for the application of magnetic fields to the sample under test. A setup for measuring the CA of liquids on magnetosensitive surfaces has been developed specifically for investigating the surfaces of magnetoactive elastomers (MAEs). The addition of a programmable linear stage, which moves a permanent magnet, allows for fine control of the magnetic field applied to the MAE without the need for large and power-consuming electromagnets. Paired with a custom control and evaluation software, this measurement setup operates semiautomatically, limiting operator error and increasing precision, speed, as well as repeatability of static and dynamic CA measurements for different magnetoactive materials. The software is equipped with robust droplet fitting algorithms to avoid experimental challenges arising with soft magnetoactive materials, such as the curling of sample edges or diffuse non-reflective surfaces. Several application examples on MAE surfaces, both processed and unprocessed, are presented. KW - magnetoactive elastomers KW - image processing KW - droplet contour fitting KW - contact angle Y1 - 2023 SN - 978-0-7918-8752-3 U6 - https://doi.org/10.1115/SMASIS2023-110998 N1 - Corresponding author: Raphael Kriegl PB - The American Society of Mechanical Engineers CY - New York, USA ER - TY - JOUR A1 - Kovalev, Alexander A1 - Belyaeva, Inna A. A1 - von Hofen, Christian A1 - Gorb, Stanislav A1 - Shamonin (Chamonine), Mikhail T1 - Magnetically Switchable Adhesion and Friction of Soft Magnetoactive Elastomers JF - Advanced Engineering Materials N2 - Herein, the effect of an applied moderate (~240 mT) magnetic field on the work of adhesion (WoA) of mechanically soft (the shear modulus ~10 kPa) magnetoactive elastomer (MAE) samples with two different mass fractions (70 and 80 wt%) of carbonyl iron powder (CIP) is concerned. The unfilled elastomer sample is used for comparison. Due to some sedimentation of filling particles, the concentration of inclusions in thin (~10 μm) subsurface layers is different. It is shown that the WoA increases (up to 1.8-fold) on the particle-enriched side (PES) in the magnetic field and its value is higher for higher filler concentration. On the particle-depleted side (PDS), WoA does not depend on particle concentration and on the magnetic field. Adhesion and friction are coupled in MAEs. No statistically significant difference in the friction coefficient, determined from the extended Amontons´ law, depending on sample side, CIP concentration, or presence of magnetic field is found. However, the PDS in the magnetic field demonstrates significantly higher critical shear stress compared to that for the PES or PDS in the absence of magnetic field. Correlations between different surface properties are discussed. Obtained results are useful for the development of magnetically controllable soft robots. Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-45283 N1 - Corresponding authors: Stanislav Gorb und Mikhail Shamonin VL - 24 IS - 10 SP - 1 EP - 8 PB - WILEY-VCH ER - TY - JOUR A1 - Kravanja, Gaia A1 - Kriegl, Raphael A1 - Hribar, Luka A1 - Glavan, Gašper A1 - Drevenšek-Olenik, Irena A1 - Shamonin (Chamonine), Mikhail A1 - Jezeršek, Matija T1 - Magnetically Actuated Surface Microstructures for Efficient Transport and Tunable Separation of Droplets and Solids JF - Advanced Engineering Materials N2 - Efficient transportation of droplets (∽10 ¹ ̶̶̶̶ 10 ² µl) and small solid objects (∽10 ¹ ̶ 10 ² mm ³ ) have important applications in many fields, such as microfluidics, lab‐on‐a‐chip devices, drug delivery, etc. A novel multifunctional surface consisting of a periodic array of micro‐lamellae from a soft magnetoactive elastomer (MAE) on a plastic substrate is reported for these purposes. The physical origin of the propulsion is the bending of soft magnetic lamellae in non‐uniform magnetic fields, which is also observed in uniform magnetic fields. The magnetoactive surface is fabricated using a facile and rapid method of laser ablation. The propulsion of items is realized using a four‐pole rotating magnet. This results in a cyclic lamellar fringe motion over the micro‐structured surface and brings an advantage of easy reciprocation of transport by rotation reversal. Two modes of object transportation are identified: “pushing” mode for precise control of droplet and solid positioning and “bouncing” mode for heavier solid objects transportation. A water droplet of 5 μl or a glass sphere with a 2.1 mm diameter can be moved at a maximum speed of 60 mm s ⁻¹ . The multifunctionality of the proposed mechatronic platform is demonstrated on the examples of selective solid‐liquid separation and droplet merging. KW - Keywordslaser micromachinings KW - magnetoactive elastomers KW - magnetoresponsivesurfaces KW - object separations KW - object transportations Y1 - 2023 U6 - https://doi.org/10.1002/adem.202301000 SN - 1527-2648 VL - 25 IS - 22 SP - 1 EP - 11 PB - Wiley-VCH ER - TY - JOUR A1 - Kravanja, Gaia A1 - Belyaeva, Inna A. A1 - Hribar, Luka A1 - Drevenšek-Olenik, Irena A1 - Shamonin (Chamonine), Mikhail A1 - Jezeršek, Matija T1 - Laser Micromachining of Magnetoactive Elastomers as Enabling Technology for Magnetoresponsive Surfaces JF - Advanced Materials Technologies N2 - A simple method for structuring of the surface of a magnetoactive elastomer (MAE) on the tens of micrometers scale, which capabilities extend beyond conventional mold-based polymer casting, is reported. The method relies on the ablation of the material by absorption of nanosecond infrared pulses from a commercial laser. It is shown that it is possible to fabricate parallel lamellar structures with a high aspect ratio (up to 6:1) as well as structures with complex scanning trajectories. The method is fast (fabrication time for the 7 × 7 mm2 is about 60 s), and the results are highly reproducible. To illustrate the capabilities of the fabrication method, both orthogonal to the MAE surface and tilted lamellar structures are fabricated. These magnetosensitive lamellae can be easily bent by ±45° using an external magnetic field of about 230 mT. It is demonstrated that this bending allows one to control the sliding angle of water droplets in a great range between a sticky (>90°) and a sliding state (<20°). Perspectives on employing this fabrication technology for magnetosensitive smart surfaces in microfluidic devices and soft robotics are discussed. Y1 - 2021 U6 - https://doi.org/10.1002/admt.202101045 VL - 7 IS - 5 SP - 1 EP - 8 PB - Wiley ER - TY - JOUR A1 - Kravanja, Gaia A1 - Belyaeva, Inna A. A1 - Hribar, Luka A1 - Drevenšek-Olenik, Irena A1 - Jezeršek, Matija A1 - Shamonin (Chamonine), Mikhail T1 - Tunable Drop Splashing on Magnetoactive Elastomers JF - Advanced Materials Interfaces N2 - The significant effect of an external dc magnetic field on the splashing behavior of ethanol drops impacting on the unstructured (flat) surface of soft magnetoactive elastomers (MAEs) is reported. The Weber number corresponding to the transition between the deposition and the splashing regime is reduced by ≈20% in a moderate magnetic field of ≈300 mT. Alongside this effect, a two-fold increase of the initial deceleration of the ejection sheet is observed for the softest sample. The main underlying mechanism for the observed phenomena is believed to be the magnetic-field-induced stiffening of the MAEs. Further possible mechanisms are magnetically induced changes in the surface roughness and magnetic-field-induced plasticity (magnetic shape memory effect). The potential application areas are magnetically regulable wetting and magneto-responsive surfaces for controlling the drop splashing. Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-24504 N1 - Corresponding author: Mikhail Shamonin VL - 8 IS - 11 SP - 1 EP - 7 PB - Wiley ER - TY - JOUR A1 - Straus, Izidor A1 - Kokot, Gašper A1 - Kravanja, Gaia A1 - Hribar, Luka A1 - Kriegl, Raphael A1 - Shamonin (Chamonine), Mikhail A1 - Jezeršek, Matija A1 - Drevenšek-Olenik, Irena T1 - Dynamically tunable lamellar surface structures from magnetoactive elastomers driven by a uniform magnetic field JF - Soft Matter N2 - Stimuli responsive materials are key ingredients for any application that requires dynamically tunable or on-demand responses. In this work we report experimental and theoretical investigation of magnetic-field driven modifications of soft-magnetic elastomers whose surface was processed by laser ablation into lamellar microstructures that can be manipulated by a uniform magnetic field. We present a minimal hybrid model that elucidates the associated deflection process of the lamellae and explains the lamellar structure frustration in terms of dipolar magnetic forces arising from the neighbouring lamellae. We experimentally determine the magnitude of the deflection as a function of magnetic flux density and explore the dynamic response of lamellae to fast changes in a magnetic field. A relationship between the deflection of lamellae and modifications of the optical reflectance of the lamellar structures is resolved. KW - Intelligente Materialien Y1 - 2023 U6 - https://doi.org/10.1039/D3SM00012E VL - Vol. 19 SP - 3357 EP - 3365 PB - Royal Society of Chemistry ER - TY - CHAP A1 - Kravanja, Gaia A1 - Belyaeva, Inna A. A1 - Hribar, Luka A1 - Drevenšek-Olenik, Irena A1 - Shamonin (Chamonine), Mikhail A1 - Jezeršek, Matija T1 - Adaptive Magneto-Responsive Surfaces Fabricated by Laser-Based Microstructuring T2 - Proceedings of the ASME 2022 Conference on Smart Materials, Adaptive Structures and Intelligent Systems (SMASIS 2022): September 12-14, 2022, Dearborn, Michigan N2 - Adaptive surface microstructures are used extensively in nature to control various surface properties such as wettability, adhesion, self-cleaning, drag reduction, etc. Regulation of these properties can be achieved with the appropriate employment of a multitude of smart materials, whose characteristics/response can be controlled by noncontact stimuli, e.g., light, heat, or magnetic field. One of the very promising magneto-regulable smart materials are magnetoactive elastomers (MAEs). They are comprised of a compliant polymer matrix with embedded micrometer-sized ferromagnetic particles. The particles interact with each other and a magnetic field. This results in remarkable tunability of the physical properties of MAEs. This paper reports a fast, resilient, and tailored method for direct surface micromachining of MAEs that enables micro-structuring without mechanical contact between the tool and the material, bypassing the usual constraints of conventional fabrication methods. It is shown that it is possible to fabricate a large variety of different microstructure geometries whose precision is limited predominantly by the size of magnetic particles. Lamellar structures with a high aspect ratio (up to 6:1) oriented either perpendicularly to the surface, can be strongly bent by applying magnetic fields in the range of 0–250 mT. KW - adaptive surfaces KW - magnetoactive elastomers KW - magneto-responsive microstructures KW - laser microstructuring Y1 - 2022 SN - 978-0-7918-8627-4 U6 - https://doi.org/10.1115/SMASIS2022-90742 PB - ASME ER - TY - JOUR A1 - Glavan, Gašper A1 - Belyaeva, Inna A1 - Shamonin (Chamonine), Mikhail T1 - Transient Response of Macroscopic Deformation of Magnetoactive Elastomeric Cylinders in Uniform Magnetic Fields JF - Polymers N2 - Significant deformations of bodies made from compliant magnetoactive elastomers (MAE) in magnetic fields make these materials promising for applications in magnetically controlled actuators for soft robotics. Reported experimental research in this context was devoted to the behaviour in the quasi-static magnetic field, but the transient dynamics are of great practical importance. This paper presents an experimental study of the transient response of apparent longitudinal and transverse strains of a family of isotropic and anisotropic MAE cylinders with six different aspect ratios in time-varying uniform magnetic fields. The time dependence of the magnetic field has a trapezoidal form, where the rate of both legs is varied between 52 and 757 kA/(s·m) and the maximum magnetic field takes three values between 153 and 505 kA/m. It is proposed to introduce four characteristic times: two for the delay of the transient response during increasing and decreasing magnetic field, as well as two for rise and fall times. To facilitate the comparison between different magnetic field rates, these characteristic times are further normalized on the rise time of the magnetic field ramp. The dependence of the normalized characteristic times on the aspect ratio, the magnetic field slew rate, maximum magnetic field values, initial internal structure (isotropic versus anisotropic specimens) and weight fraction of the soft-magnetic filler are obtained and discussed in detail. The normalized magnetostrictive hysteresis loop is introduced, and used to explain why the normalized delay times vary with changing experimental parameters. KW - magnetoactive elastomer KW - magnetorheological elastomer KW - macroscopic deformation KW - magnetostriction KW - time-varying magnetic field Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-71067 SN - 2073-4360 N1 - Corresponding author der OTH Regensburg: Gašper Glavan VL - 16 IS - 5, Special Issue Magnetic Polymer Composites: Design and Application II PB - MDPI CY - Basel, Schweiz ER -