@article{SydorukRadkovskayaZhuromskyyetal., author = {Sydoruk, O. and Radkovskaya, Anna A. and Zhuromskyy, Oleksandr and Shamonina, Ekaterina and Shamonin (Chamonine), Mikhail and Stevens, Chris J. and Faulkner, Grahame and Edwards, David J. and Solymar, L.}, title = {Tailoring the near-field guiding properties of magnetic metamaterials with two resonant elements per unit cell}, series = {PHYSICAL REVIEW B}, volume = {73}, journal = {PHYSICAL REVIEW B}, number = {22}, publisher = {APS}, doi = {10.1103/PhysRevB.73.224406}, abstract = {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.}, language = {en} } @article{HesmerTatartschukZhuromskyyetal., author = {Hesmer, Frank and Tatartschuk, Eugen and Zhuromskyy, Oleksandr and Radkovskaya, Anna A. and Shamonin (Chamonine), Mikhail and Hao, Tong and Stevens, Chris J. and Faulkner, Grahame and Edwards, David J. and Shamonina, Ekaterina}, title = {Coupling mechanisms for split ring resonators: Theory and experiment}, series = {Physica status solidi b}, volume = {244}, journal = {Physica status solidi b}, number = {4}, publisher = {Wiley}, doi = {10.1002/pssb.200674501}, pages = {1170 -- 1175}, abstract = {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.}, language = {en} } @article{KlankHagedornHolthausetal., author = {Klank, Michael and Hagedorn, Oliver and Holthaus, Carsten and Shamonin (Chamonine), Mikhail and D{\"o}tsch, Horst}, title = {Characterization and optimization of magnetic garnet films for magneto-optical visualization of magnetic field distributions}, series = {NDT \& E International}, volume = {36}, journal = {NDT \& E International}, number = {6}, publisher = {Elsevier}, doi = {10.1016/S0963-8695(03)00012-4}, pages = {375 -- 381}, abstract = {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.}, language = {en} } @article{LukyanetsSnarskiiShamoninChamonineetal., author = {Lukyanets, S. and Snarskii, Andrei A. and Shamonin (Chamonine), Mikhail and Bakaev, V. V.}, title = {Calculation of magnetic leakage field from a surface defect in a linear ferromagnetic material: an analytical approach}, series = {NDT \& E International}, volume = {36}, journal = {NDT \& E International}, number = {1}, publisher = {Elsevier}, doi = {10.1016/s0963-8695(02)00071-3}, pages = {51 -- 55}, abstract = {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.}, language = {en} } @article{BakaevSnarskiiShamoninChamonine, author = {Bakaev, V. V. and Snarskii, Andrei A. and Shamonin (Chamonine), Mikhail}, title = {The permeability and remanent magnetization of a randomly inhomogeneous two-phase medium}, series = {Technical Physics}, volume = {47}, journal = {Technical Physics}, number = {1}, publisher = {Springer}, doi = {10.1134/1.1435901}, pages = {125 -- 128}, abstract = {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.}, language = {en} } @article{BakaevSnarskiiShamoninChamonine, author = {Bakaev, V. V. and Snarskii, Andrei A. and Shamonin (Chamonine), Mikhail}, title = {The effective magnetic permeability of a two-phase fibred ferromagnetic composite}, series = {Technical Physics}, volume = {46}, journal = {Technical Physics}, number = {12}, publisher = {Springer}, doi = {10.1134/1.1427995}, pages = {1571 -- 1574}, language = {en} } @article{KovalevBelyaevavonHofenetal., author = {Kovalev, Alexander and Belyaeva, Inna A. and von Hofen, Christian and Gorb, Stanislav and Shamonin (Chamonine), Mikhail}, title = {Magnetically Switchable Adhesion and Friction of Soft Magnetoactive Elastomers}, series = {Advanced Engineering Materials}, volume = {24}, journal = {Advanced Engineering Materials}, number = {10}, publisher = {WILEY-VCH}, doi = {10.1002/adem.202200372}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-45283}, pages = {1 -- 8}, abstract = {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.}, language = {en} } @article{LohmeyerShamoninChamonineHertel, author = {Lohmeyer, Manfred and Shamonin (Chamonine), Mikhail and Hertel, Peter}, title = {Integrated optical circulator based on radiatively coupled magneto-optic waveguides}, series = {Optical Engineering}, volume = {36}, journal = {Optical Engineering}, number = {3}, publisher = {SPIE}, doi = {10.1117/1.601255}, pages = {889 -- 895}, abstract = {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.}, language = {en} } @article{BelyaevaKramarenkoStepanovetal., author = {Belyaeva, Inna A. and Kramarenko, Elena Yu and Stepanov, Gennady V. and Sorokin, Vladislav V. and Stadler, Dominik and Shamonin (Chamonine), Mikhail}, title = {Transient magnetorheological response of magnetoactive elastomers to step and pyramid excitations}, series = {SOFT MATTER}, volume = {12}, journal = {SOFT MATTER}, number = {11}, publisher = {ROYAL SOC CHEMISTRY}, doi = {10.1039/c5sm02690c}, pages = {2901 -- 2913}, abstract = {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.}, language = {en} } @article{BelyaevaKramarenkoShamoninChamonine, author = {Belyaeva, Inna A. and Kramarenko, Elena Yu and Shamonin (Chamonine), Mikhail}, title = {Magnetodielectric effect in magnetoactive elastomers: Transient response and hysteresis}, series = {POLYMER}, volume = {127}, journal = {POLYMER}, publisher = {ELSEVIER}, doi = {10.1016/j.polymer.2017.08.056}, pages = {119 -- 128}, abstract = {Magnetodielectric properties of magnetoactive elastomers comprising micrometer-sized iron particles dispersed in compliant elastomer matrices are experimentally studied in stepwise time-varying dc magnetic fields. It is found that imposition of magnetic field significantly increases both the effective lossless permittivity of these composite materials as well as their effective conductivity. These magnetodielectric effects are more pronounced for larger concentrations of soft-magnetic filler particles and softer elastomer matrices. The largest observed relative change of the effective dielectric constant in the maximum magnetic field of 0.57 T is of the order of 1000\%. The largest observed absolute change of the loss tangent is approximately 0.8. The transient response of the magnetodielectric effect to a step magnetic-field excitation can be rather complex. It changes from a simple monotonic growth with time for small magnetic-field steps (<0.1 T) to a non-monotonic behavior with a significant rapidly appearing overshoot for large magnetic-field steps (>0.3 T). The settling time to the magnetic-field step excitation can reach roughly 1000 s and it depends on the applied magnetic field and sample composition. There is also significant hysteresis of the magnetodielectric effect on the externally applied magnetic field. These findings are attributed to the rearrangement of ferromagnetic filler particles in external magnetic fields. The results will be useful for understanding and predicting the transient behavior of magnetoactive elastomers in applications where the control magnetic field is time dependent. (C) 2017 Elsevier Ltd. All rights reserved.}, language = {en} } @article{SorokinBelyaevaShamoninChamonineetal., author = {Sorokin, Vladislav V. and Belyaeva, Inna A. and Shamonin (Chamonine), Mikhail and Kramarenko, Elena Yu}, title = {Magnetorheological response of highly filled magnetoactive elastomers from perspective of mechanical energy density: Fractal aggregates above the nanometer scale?}, series = {Physical Review E}, volume = {95}, journal = {Physical Review E}, number = {6}, publisher = {Amer Physical Soc}, doi = {10.1103/PhysRevE.95.062501}, abstract = {The dynamic shear modulus of magnetoactive elastomers containing 70 and 80 mass \% of carbonyl iron microparticles is measured as a function of strain amplitude via dynamic torsion oscillations in various magnetic fields. The results are presented in terms of the mechanical energy density and considered in the framework of the conventional Kraus model. The form exponent of the Kraus model is further related to a physical model of Huber et al. [Huber et al., J. Phys.: Condens. Matter 8, 409 (1996)] that uses a realistic representation for the cluster network possessing fractal structure. Two mechanical loading regimes are identified. At small strain amplitudes the exponent beta of the Kraus model changes in an externally applied magnetic field due to rearrangement of ferromagnetic-filler particles, while at large strain amplitudes, the exponent beta seems to be independent of the magnetic field. The critical mechanical energy characterizing the transition between these two regimes grows with the increasing magnetic field. Similarities between agglomeration and deagglomeration of magnetic filler under simultaneously applied magnetic field and mechanical shear and the concept of jamming transition are discussed. It is proposed that the magnetic field should be considered as an additional parameter to the jamming phase diagram of rubbers filled with magnetic particles.}, language = {en} } @article{BelyaevaKleppLemmeletal., author = {Belyaeva, Inna A. and Klepp, J{\"u}rgen and Lemmel, Hartmut and Shamonin (Chamonine), Mikhail}, title = {Feasibility of Probing the Filler Restructuring in Magnetoactive Elastomers by Ultra-Small-Angle Neutron Scattering}, series = {Applied Sciences}, volume = {11}, journal = {Applied Sciences}, number = {10}, publisher = {MDPI}, address = {Basel}, doi = {10.3390/app11104470}, pages = {1 -- 9}, abstract = {Ultra-small-angle neutron scattering (USANS) experiments are reported on isotropic magnetoactive elastomer (MAE) samples with different concentrations of micrometer-sized iron particles in the presence of an in-plane magnetic field up to 350 mT. The effect of the magnetic field on the scattering curves is observed in the scattering vector range between 2.5 x 10(-5) and 1.85 x 10(-4) angstrom(-1). It is found that the neutron scattering depends on the magnetization history (hysteresis). The relation of the observed changes to the magnetic-field-induced restructuring of the filler particles is discussed. The perspectives of employing USANS for investigations of the internal microstructure and its changes in magnetic field are considered.}, language = {en} } @article{GlavanBelyaevaShamoninChamonine, author = {Glavan, Gašper and Belyaeva, Inna A. and Shamonin (Chamonine), Mikhail}, title = {On the Piezomagnetism of Magnetoactive Elastomeric Cylinders in Uniform Magnetic Fields: Height Modulation in the Vicinity of an Operating Point by Time-Harmonic Fields}, series = {Polymers}, volume = {16}, journal = {Polymers}, number = {19}, doi = {10.3390/polym16192706}, abstract = {Soft magnetoactive elastomers (MAEs) are currently considered to be promising materials for actuators in soft robotics. Magnetically controlled actuators often operate in the vicinity of a bias point. Their dynamic properties can be characterized by the piezomagnetic strain coefficient, which is a ratio of the time-harmonic strain amplitude to the corresponding magnetic field strength. Herein, the dynamic strain response of a family of MAE cylinders to the time-harmonic (frequency of 0.1-2.5 Hz) magnetic fields of varying amplitude (12.5 kA/m-62.5 kA/m), superimposed on different bias magnetic fields (25-127 kA/m), is systematically investigated for the first time. Strain measurements are based on optical imaging with sub-pixel resolution. It is found that the dynamic strain response of MAEs is considerably different from that in conventional magnetostrictive polymer composites (MPCs), and it cannot be described by the effective piezomagnetic constant from the quasi-static measurements. The obtained maximum values of the piezomagnetic strain coefficient (∼102 nm/A) are one to two orders of magnitude higher than in conventional MPCs, but there is a significant phase lag (35-60°) in the magnetostrictive response with respect to an alternating magnetic field. The experimental dependencies of the characteristics of the alternating strain on the amplitude of the alternating field, bias field, oscillation frequency, and aspect ratio of cylinders are given for several representative examples. It is hypothesized that the main cause of observed peculiarities is the non-linear viscoelasticity of these composite materials.}, language = {en} } @article{JezeršekKrieglKravanjaetal., author = {Jezeršek, Matija and Kriegl, Raphael and Kravanja, Gaia and Hribar, Luka and Drevenšek-Olenik, Irena and Unold, Heiko and Shamonin (Chamonine), Mikhail}, title = {Control of Droplet Impact through Magnetic Actuation of Surface Microstructures}, series = {Advanced Materials Interfaces}, volume = {10}, journal = {Advanced Materials Interfaces}, number = {11}, publisher = {Wiley}, doi = {10.1002/admi.202202471}, abstract = {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.}, language = {en} } @article{GlavanKettlBrunhuberetal., author = {Glavan, Gašper and Kettl, Wolfgang and Brunhuber, Alexander and Shamonin (Chamonine), Mikhail and Drevenšek-Olenik, Irena}, title = {Effect of Material Composition on Tunable Surface Roughness of Magnetoactive Elastomers}, series = {Polymers}, volume = {11}, journal = {Polymers}, number = {4}, publisher = {MDPI}, address = {Basel}, doi = {10.3390/polym11040594}, pages = {1 -- 13}, abstract = {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.}, language = {en} } @article{GlavanSalamonBelyaevaetal., author = {Glavan, Gašper and Salamon, Peter and Belyaeva, Inna A. and Shamonin (Chamonine), Mikhail and Drevenšek-Olenik, Irena}, title = {Tunable surface roughness and wettability of a soft magnetoactive elastomer}, series = {Journal of applied polymer science}, volume = {135}, journal = {Journal of applied polymer science}, number = {18}, publisher = {Wiley}, doi = {10.1002/app.46221}, abstract = {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.}, language = {en} } @article{KravanjaKrieglHribaretal., author = {Kravanja, Gaia and Kriegl, Raphael and Hribar, Luka and Glavan, Gašper and Drevenšek-Olenik, Irena and Shamonin (Chamonine), Mikhail and Jezeršek, Matija}, title = {Magnetically Actuated Surface Microstructures for Efficient Transport and Tunable Separation of Droplets and Solids}, series = {Advanced Engineering Materials}, volume = {25}, journal = {Advanced Engineering Materials}, number = {22}, publisher = {Wiley-VCH}, issn = {1527-2648}, doi = {10.1002/adem.202301000}, pages = {1 -- 11}, abstract = {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.}, language = {en} } @article{KravanjaBelyaevaHribaretal., author = {Kravanja, Gaia and Belyaeva, Inna A. and Hribar, Luka and Drevenšek-Olenik, Irena and Shamonin (Chamonine), Mikhail and Jezeršek, Matija}, title = {Laser Micromachining of Magnetoactive Elastomers as Enabling Technology for Magnetoresponsive Surfaces}, series = {Advanced Materials Technologies}, volume = {7}, journal = {Advanced Materials Technologies}, number = {5}, publisher = {Wiley}, doi = {10.1002/admt.202101045}, pages = {1 -- 8}, abstract = {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.}, language = {en} } @article{KravanjaBelyaevaHribaretal., author = {Kravanja, Gaia and Belyaeva, Inna A. and Hribar, Luka and Drevenšek-Olenik, Irena and Jezeršek, Matija and Shamonin (Chamonine), Mikhail}, title = {Tunable Drop Splashing on Magnetoactive Elastomers}, series = {Advanced Materials Interfaces}, volume = {8}, journal = {Advanced Materials Interfaces}, number = {11}, publisher = {Wiley}, doi = {10.1002/admi.202100235}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-24504}, pages = {1 -- 7}, abstract = {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.}, language = {en} } @inproceedings{KravanjaBelyaevaHribaretal., author = {Kravanja, Gaia and Belyaeva, Inna A. and Hribar, Luka and Drevenšek-Olenik, Irena and Shamonin (Chamonine), Mikhail and Jezeršek, Matija}, title = {Adaptive Magneto-Responsive Surfaces Fabricated by Laser-Based Microstructuring}, series = {Proceedings of the ASME 2022 Conference on Smart Materials, Adaptive Structures and Intelligent Systems (SMASIS 2022): September 12-14, 2022, Dearborn, Michigan}, booktitle = {Proceedings of the ASME 2022 Conference on Smart Materials, Adaptive Structures and Intelligent Systems (SMASIS 2022): September 12-14, 2022, Dearborn, Michigan}, publisher = {ASME}, isbn = {978-0-7918-8627-4}, doi = {10.1115/SMASIS2022-90742}, pages = {6}, abstract = {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.}, language = {en} } @misc{KrieglKravanjaHribaretal., author = {Kriegl, Raphael and Kravanja, Gaia and Hribar, Luka and Jezeršek, Matija and Drevenšek-Olenik, Irena and Shamonin (Chamonine), Mikhail}, title = {Characterization of Wetting Properties of Magnetoactive Elastomer Surfaces}, series = {Proceedings of the ASME Conference on Smart Materials, Adaptive Structures and Intelligent Systems (SMASIS) - 2023, September 11-13, 2023 Austin, Texas, USA}, journal = {Proceedings of the ASME Conference on Smart Materials, Adaptive Structures and Intelligent Systems (SMASIS) - 2023, September 11-13, 2023 Austin, Texas, USA}, publisher = {The American Society of Mechanical Engineers}, address = {New York, USA}, isbn = {978-0-7918-8752-3}, doi = {10.1115/SMASIS2023-110998}, abstract = {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.}, language = {en} } @article{GlavanBelyaevaDrevenšek‐Oleniketal., author = {Glavan, Gašper and Belyaeva, Inna A. and Drevenšek-Olenik, Irena and Shamonin (Chamonine), Mikhail}, title = {Experimental study of longitudinal, transverse and volume strains of magnetoactive elastomeric cylinders in uniform magnetic fields}, series = {Journal of Magnetism and Magnetic Materials}, volume = {579}, journal = {Journal of Magnetism and Magnetic Materials}, publisher = {Elsevier}, issn = {0304-8853}, doi = {10.1016/j.jmmm.2023.170826}, abstract = {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.}, language = {en} } @article{HoernerKrykanovChashinetal., author = {H{\"o}rner, Eduard and Krykanov, Ivan M. and Chashin, Dmitri V. and Fetisov, Yuri K. and Fetisov, Leonid Y. and Shamonin (Chamonine), Mikhail}, title = {Magnetoelectric characteristics of cobalt-iron alloy-lead zirconate titanate bilayer planar structures}, series = {International Journal of Materials Research}, volume = {103}, journal = {International Journal of Materials Research}, number = {11}, publisher = {De Gruyter}, doi = {10.3139/146.110776}, abstract = {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.}, language = {de} } @article{StrausKokotKravanjaetal., author = {Straus, Izidor and Kokot, Gašper and Kravanja, Gaia and Hribar, Luka and Kriegl, Raphael and Shamonin (Chamonine), Mikhail and Jezeršek, Matija and Drevenšek-Olenik, Irena}, title = {Dynamically tunable lamellar surface structures from magnetoactive elastomers driven by a uniform magnetic field}, series = {Soft Matter}, volume = {Vol. 19}, journal = {Soft Matter}, publisher = {Royal Society of Chemistry}, doi = {10.1039/D3SM00012E}, pages = {3357 -- 3365}, abstract = {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.}, language = {en} } @article{StrausKravanjaHribaretal., author = {Straus, Izidor and Kravanja, Gaia and Hribar, Luka and Kriegl, Raphael and Jezeršek, Matija and Shamonin (Chamonine), Mikhail and Drevenšek-Olenik, Irena and Kokot, Gašper}, title = {Surface Modification of Magnetoactive Elastomers by Laser Micromachining}, series = {Materials}, volume = {2024}, journal = {Materials}, number = {17 / 7}, publisher = {MDPI AG}, address = {Basel, Switzerland}, doi = {10.3390/ma17071550}, pages = {12}, abstract = {It has been recently demonstrated that laser micromachining of magnetoactive elastomers is a very convenient method for fabricating dynamic surface microstructures with magnetically tunable properties, such as wettability and surface reflectivity. In this study, we investigate the impact of the micromachining process on the fabricated material's structural properties and its chemical composition. By employing scanning electron microscopy, we investigate changes in size distribution and spatial arrangement of carbonyl iron microparticles dispersed in the polydimethylsiloxane (PDMS) matrix as a function of laser irradiation. Based on the images obtained by a low vacuum secondary electron detector, we analyze modifications of the surface topography. The results show that most profound modifications occur during the low-exposure (8 J/cm^2) treatment of the surface with the laser beam. Our findings provide important insights for developing theoretical models of functional properties of laser-sculptured microstructures from magnetoactive elastomers.}, language = {en} } @inproceedings{KrieglJezeršekKravanjaetal., author = {Kriegl, Raphael and Jezeršek, Matija and Kravanja, Gaia and Hribar, Luka and Kokot, Gašper and Drevenšek-Olenik, Irena and Shamonin (Chamonine), Mikhail}, title = {Characterization of Tunable Rebound Properties of Microstructured Magnetoactive Elastomers}, series = {ASME 2024 Conference on Smart Materials, Adaptive Structures and Intelligent Systems (SMASIS), September 9-11, 2024, Atlanta, Georgia, USA}, booktitle = {ASME 2024 Conference on Smart Materials, Adaptive Structures and Intelligent Systems (SMASIS), September 9-11, 2024, Atlanta, Georgia, USA}, publisher = {American Society of Mechanical Engineers}, address = {New York, USA}, isbn = {978-0-7918-8832-2}, doi = {10.1115/SMASIS2024-139154}, abstract = {We present a novel method to control the rebounding behavior of small mm-sized solid balls by employing magnetoactive elastomers (MAEs) with microstructured surfaces. An MAE is a composite material consisting of μm-sized ferromagnetic particles dispersed in a soft elastomer (e.g., polydimethylsiloxane) matrix. In the act of rebounding, the ball hits an MAE surface and bounces back. The MAE samples contained 75 wt.\% of iron. This composite material is known to respond to an applied magnetic field with increased stiffness (due to the magnetorheological effect) and plasticity. To adjust the rebound properties, the top layer of the MAE material was additionally modified by micromachining lamellar structures with different dimensions on the 100 μm scale via laser ablation. Due to the resulting high aspect ratio, these surface structures were sensitive to the magnetic field direction. The lamellas could stand up straight or lay down flat. The rebound behavior was evaluated by using a custom build apparatus that facilitates dropping of the balls in a precise and repeatable manner. A ball was dropped from different heights. The ball trajectory was captured with a high-speed camera to investigate the rebound properties. The recorded video was processed using a custom software written in Python. The experimental procedure and data processing algorithms are presented in detail. The results for the samples with different geometrical dimensions are provided as examples. It is made evident that the magnetic field influences the rebound properties of small non-magnetic balls impinging microstructured MAE surfaces. The change in surface topography is an effective way to control the ball rebound. The fabrication flexibility in geometrical dimensions of surface microstructures opens a convenient way to tune the desired response to magnetic fields. The presented idea may find applications in impact mitigation or small-scale sorting machinery, e.g. for recycling.}, language = {en} } @article{LovšinBrandlGlavanetal., author = {Lovšin, Matija and Brandl, Dominik and Glavan, Gašper and Belyaeva, Inna A. and Cmok, Luka and Coga, Lucija and Kalin, Mitjan and Shamonin (Chamonine), Mikhail and Drevenšek-Olenik, Irena}, title = {Reconfigurable Surface Micropatterns Based on the Magnetic Field-Induced Shape Memory Effect in Magnetoactive Elastomers}, series = {Polymers}, volume = {13}, journal = {Polymers}, number = {24}, publisher = {MDPI}, doi = {10.3390/polym13244422}, abstract = {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.}, language = {en} } @inproceedings{HolthausHagedornKlanketal., author = {Holthaus, Carsten and Hagedorn, Oliver and Klank, Michael and Shamonin (Chamonine), Mikhail and Trifonov, A. and D{\"o}tsch, Horst}, title = {Preparation and Characterization of Sensitive Magnetic Garnet Films for MOI Applications}, series = {Magneto-Optical Imaging. Proceedings of the NATO Advanced Research Workshop on Magneto-Optical Imaging, {\O}ystese, Norway, 28 - 30 August 2003}, booktitle = {Magneto-Optical Imaging. Proceedings of the NATO Advanced Research Workshop on Magneto-Optical Imaging, {\O}ystese, Norway, 28 - 30 August 2003}, publisher = {Kluwer}, address = {Dodrecht}, doi = {10.1007/978-94-007-1007-8_42}, pages = {329 -- 336}, abstract = {Magnetic garnet films prepared by liquid phase epitaxy on paramagnetic substrates of gadolinium gallium garnet are currently used for the imaging of magnetic field distributions. This application is based on the Faraday rotation which can be strongly enhanced by bismuth incorporation. For gray scale imaging the plane of the sensor film should be an easy plane of magnetization so that no domains nucleate. However, incorporation of bismuth induces a strong positive uniaxial anisotropy perpendicular to the film plane, especially if films of [111] orientation are used. To counteract this unwanted behavior neodymium and/or praseodymium are substituted in addition to bismuth. These two elements cause a very strong negative anisotropy. This is tested experimentally by growing series of garnet films with gradually changing composition and growth parameters.}, language = {en} } @article{BodnarukBrunhuberKalitaetal., author = {Bodnaruk, Andrii V. and Brunhuber, Alexander and Kalita, Viktor M. and Kulyk, Mykola M. and Snarskii, Andrei A. and Lozenko, Albert F. and Ryabchenko, Sergey M. and Shamonin (Chamonine), Mikhail}, title = {Temperature-dependent magnetic properties of a magnetoactive elastomer: Immobilization of the soft-magnetic filler}, series = {Journal of Applied Physics}, volume = {123}, journal = {Journal of Applied Physics}, number = {11}, publisher = {AIP Publishing}, doi = {10.1063/1.5023891}, abstract = {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.}, language = {en} } @misc{ScharfenbergMottokArtmannetal., author = {Scharfenberg, Georg and Mottok, J{\"u}rgen and Artmann, Christina and Hobelsberger, Martin and Paric, Ivan and Großmann, Benjamin and Pohlt, Clemens and Wackerbarth, Alena and Pausch, Uli and Heidrich, Christiane and Fadanelli, Martin and Elsner, Michael and P{\"o}cher, Daniel and Pittroff, Lenz and Beer, Stefan and Br{\"u}ckl, Oliver and Haslbeck, Matthias and Sterner, Michael and Thema, Martin and Muggenthaler, Nicole and Lenck, Thorsten and G{\"o}tz, Philipp and Eckert, Fabian and Deubzer, Michael and Stingl, Armin and Simsek, Erol and Kr{\"a}mer, Stefan and Großmann, Benjamin and Schlegl, Thomas and Niedersteiner, Sascha and Berlehner, Thomas and Joblin, Mitchell and Mauerer, Wolfgang and Apel, Sven and Siegmund, Janet and Riehle, Dirk and Weber, Joachim and Palm, Christoph and Zobel, Martin and Al-Falouji, Ghassan and Prestel, Dietmar and Scharfenberg, Georg and Mandl, Roland and Deinzer, Arnulf and Halang, W. and Margraf-Stiksrud, Jutta and Sick, Bernhard and Deinzer, Renate and Scherzinger, Stefanie and Klettke, Meike and St{\"o}rl, Uta and Wiech, Katharina and Kubata, Christoph and Sindersberger, Dirk and Monkman, Gareth J. and Dollinger, Markus and Dembianny, Sven and K{\"o}lbl, Andreas and Welker, Franz and Meier, Matthias and Thumann, Philipp and Swidergal, Krzysztof and Wagner, Marcus and Haug, Sonja and Vernim, Matthias and Seidenst{\"u}cker, Barbara and Weber, Karsten and Arsan, Christian and Schone, Reinhold and M{\"u}nder, Johannes and Schroll-Decker, Irmgard and Dillinger, Andrea Elisabeth and Fuchshofer, Rudolf and Monkman, Gareth J. and Shamonin (Chamonine), Mikhail and Geith, Markus A. and Koch, Fabian and {\"U}hlin, Christian and Schratzenstaller, Thomas and Saßmannshausen, Sean Patrick and Auchter, Eberhard and Kriz, Willy and Springer, Othmar and Thumann, Maria and Kusterle, Wolfgang and Obermeier, Andreas and Udalzow, Anton and Schmailzl, Anton and Hierl, Stefan and Langer, Christoph and Schreiner, Rupert}, title = {Forschungsbericht 2015}, editor = {Baier, Wolfgang}, address = {Regensburg}, organization = {Ostbayerische Technische Hochschule Regensburg}, isbn = {978-3-00-048589-3}, doi = {10.35096/othr/pub-1386}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-13867}, language = {de} } @article{ShamoninChamonineKlankHagedornetal., author = {Shamonin (Chamonine), Mikhail and Klank, Michael and Hagedorn, Oliver and D{\"o}tsch, Horst}, title = {Magneto-optical visualization of metal-loss defects in a ferromagnetic plate: experimental verification of theoretical modeling}, series = {Applied optics}, volume = {40}, journal = {Applied optics}, number = {19}, publisher = {Optica Publishing Group}, doi = {10.1364/ao.40.003182}, pages = {3182 -- 3189}, abstract = {Rare-earth iron garnet films with in-plane magnetic anisotropy grown on [111]-oriented substrates are promising for the visualization of magnetic leakage fields in nondestructive evaluation. Such magneto-optical films have to be specifically engineered, and we give an example of this technology. To assess the validity and accuracy of finite-element calculations of a magnetization assembly combined with the physical modeling of the image formation, comparisons between calculated and experimentally obtained magneto-optical images of metal-loss defects have been made. A convincing quantitative agreement is demonstrated. It is shown that both physical and computer modeling techniques allow for a predictive engineering design of the prospective applications and provide greater insight into the method.}, language = {en} } @article{BodnarukAndriiVBrunhuberetal., author = {Bodnaruk, and Andrii V., and Brunhuber, Alexander and Kalita, Viktor M. and Kulyk, Mykola M. and Kurzweil, Peter and Snarskii, Andrei A. and Lozenko, Albert F. and Ryabchenko, Sergey M. and Shamonin (Chamonine), Mikhail}, title = {Magnetic anisotropy in magnetoactive elastomers, enabled by matrix elasticity}, series = {Polymer}, volume = {162}, journal = {Polymer}, number = {January}, publisher = {Elsevier}, doi = {10.1016/j.polymer.2018.12.027}, pages = {63 -- 72}, abstract = {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.}, language = {en} } @inproceedings{DoetschKlankHagedornetal., author = {D{\"o}tsch, Horst and Klank, Michael and Hagedorn, Oliver and Holthaus, Carsten and Shamonin (Chamonine), Mikhail and Trifonov, A.}, title = {Optimization of Magnetic Garnet Films for Magneto-Optical Imaging of Magnetic Field Distributions}, series = {Magneto-Optical Imaging. Proceedings of the NATO Advanced Research Workshop on Magneto-Optical Imaging, {\O}ystese, Norway, 28 - 30 August 2003}, booktitle = {Magneto-Optical Imaging. Proceedings of the NATO Advanced Research Workshop on Magneto-Optical Imaging, {\O}ystese, Norway, 28 - 30 August 2003}, publisher = {KLuwer}, address = {Dodrecht}, doi = {10.1007/978-94-007-1007-8_39}, pages = {301 -- 309}, abstract = {Rare-earth iron garnet films are currently applied for magneto-optical imaging of magnetic field distributions. The physical properties of the films can be controlled by the chemical composition, the growth conditions and the crystallographic orientation. The sensor properties must be optimized according to the application desired. A new optimization method is introduced based on the swing of the photoresponse. An application example is presented. Furthermore, the sensitivity can be strongly enhanced using specific crystallographic orientations which induce an easy plane of magnetization being tilted with respect to the film plane. Experimental results of a [112] oriented garnet film are in good agreement with calculations. The influence of the cubic anisotropy on the sensor performance is discussed. Finally, it is shown that also domain films can be applied for magneto-optical imaging.}, language = {en} } @article{KlankHagedornHolthausetal., author = {Klank, Michael and Hagedorn, Oliver and Holthaus, Carsten and Shamonin (Chamonine), Mikhail and D{\"o}tsch, Horst}, title = {Characterization and optimization of magnetic garnet films for magneto-optical visualization of magnetic field distributions}, series = {NDT \& E International}, volume = {36}, journal = {NDT \& E International}, number = {6}, publisher = {Elsevier}, doi = {10.1016/S0963-8695(03)00012-4}, pages = {375 -- 381}, abstract = {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.}, language = {en} } @article{KrieglKravanjaHribaretal., author = {Kriegl, Raphael and Kravanja, Gaia and Hribar, Luka and Čoga, Lucija and Drevenšek-Olenik, Irena and Jezeršek, Matija and Kalin, Mitjan and Shamonin (Chamonine), Mikhail}, title = {Microstructured Magnetoactive Elastomers for Switchable Wettability}, series = {Polymers}, volume = {14}, journal = {Polymers}, number = {18}, publisher = {MDPI}, doi = {10.3390/polym14183883}, pages = {1 -- 21}, abstract = {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.}, language = {en} } @article{ShamoninChamonineBeukerRosenetal., author = {Shamonin (Chamonine), Mikhail and Beuker, T. and Rosen, P. and Klank, Michael and Hagedorn, Oliver and D{\"o}tsch, Horst}, title = {Feasibility of magneto-optic flaw visualization using thin garnet films}, series = {NDT \& E International}, volume = {33}, journal = {NDT \& E International}, number = {8}, publisher = {Elsevier}, doi = {10.1016/s0963-8695(00)00028-1}, pages = {547 -- 553}, abstract = {We investigate the feasibility of using rare-earth iron garnet films grown on (111)-oriented substrates as magneto-optic indicator films for the visualization of magnetic leakage fields in non-destructive evaluation. In most cases the leakage field of the defect has a strong component in the film plane. The influence of this in-plane dc magnetic field on the image formation is investigated. It is shown that the presence of a strong in-plane magnetic field allows one to extend the dynamic range of the out-of-plane field imposed by the uniaxial anisotropy field HA. On the other hand, an in-plane field reduces the sensitivity. The guidelines for selecting parameters of magneto-optic indicator films are given.}, language = {en} } @article{KlankHagedornShamoninChamonineetal., author = {Klank, Michael and Hagedorn, Oliver and Shamonin (Chamonine), Mikhail and Rosen, H. and D{\"o}tsch, Horst}, title = {Sensitive magneto-optical sensors for visualization of magnetic fields using garnet films of specific orientations}, series = {Journal of Applied Physics}, volume = {92}, journal = {Journal of Applied Physics}, publisher = {AIP}, doi = {10.1063/1.1516839}, abstract = {Garnet films of high Faraday rotation are applied as magneto-optical sensors to visualize the spatial distribution of magnetic fields. Using specific orientations, the induced anisotropy can generate an easy plane of magnetization which is inclined with respect to the film plane. If the magnetization lies in this plane a very high sensitivity can be 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.}, language = {en} } @inproceedings{DoetschHolthausTrifonovetal., author = {D{\"o}tsch, Horst and Holthaus, Carsten and Trifonov, A. and Klank, Michael and Hagedorn, Oliver and Shamonin (Chamonine), Mikhail and Sch{\"u}tzmann, J.}, title = {Application of Magnetic Garnet Films for Magnetooptical Imaging of Magnetic Field Distributions}, series = {MRS Online Proceedings Library}, booktitle = {MRS Online Proceedings Library}, publisher = {Springer}, doi = {10.1557/PROC-834-J6.1}, pages = {18 -- 29}, abstract = {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.}, language = {en} } @misc{MauererRexhepajMonkmanetal., author = {Mauerer, Wolfgang and Rexhepaj, Tanja and Monkman, Gareth J. and Sindersberger, Dirk and Diermeier, Andreas and Neidhart, Thomas and Wolfrum, Dominik and Sterner, Michael and Heberl, Michael and Nusko, Robert and Maier, Georg and Nagl, Klaus and Reuter, Monika and Hofrichter, Andreas and Lex, Thomas and Lesch, Florian and Kieninger, B{\"a}rbel and Szalo, Alexander Eduard and Zehner, Alexander and Palm, Christoph and Joblin, Mitchell and Apel, Sven and Ramsauer, Ralf and Lohmann, Daniel and Westner, Markus and Strasser, Artur and Munndi, Maximilian and Ebner, Lena and Elsner, Michael and Weiß, Nils and Segerer, Matthias and Hackenberg, Rudolf and Steger, Sebastian and Schmailzl, Anton and Dostalek, Michael and Armbruster, Dominik and Koch, Fabian and Hierl, Stefan and Thumann, Philipp and Swidergal, Krzysztof and Wagner, Marcus and Briem, Ulrich and Diermeier, Andreas and Spreitzer, Stefan and Beiderbeck, Sabrina and Hook, Christian and Zobel, Martin and Weber, Tim and Groß, Simon and Penzkofer, Rainer and Dendorfer, Sebastian and Schillitz, Ingo and Bauer, Thomas and Rudolph, Clarissa and Schmidt, Katja and Liebetruth, Thomas and Hamer, Markus and Haug, Sonja and Vernim, Matthias and Weber, Karsten and Saßmannshausen, Sean Patrick and Books, Sebastian and Neuleitner, Nikolaus and Rechenauer, Christian and Steffens, Oliver and Kusterle, Wolfgang and G{\"o}mmel, Roland and Wellnitz, Felix and Stierstorfer, Johannes and Stadler, Dominik and Hofmann, Matthias J. and Motschmann, Hubert and Shamonin (Chamonine), Mikhail and Bleicher, Veronika and Fischer, Sebastian and Hackenberg, Rudolf and Horn, Anton and Kawasch, Raphael and Petzenhauser, Michael and Probst, Tobias and Udalzow, Anton and Dams, Florian and Schreiner, Rupert and Langer, Christoph and Prommesberger, Christian and Ławrowski, Robert Damian}, title = {Forschungsbericht 2016}, editor = {Baier, Wolfgang}, address = {Regensburg}, organization = {Ostbayerische Technische Hochschule Regensburg}, doi = {10.35096/othr/pub-1384}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-13840}, language = {de} } @misc{LautenschlaegerLeisDendorferetal., author = {Lautenschl{\"a}ger, Toni and Leis, Alexander and Dendorfer, Sebastian and Palm, Christoph and Schreiner, Rupert and Langer, Christoph and Prommesberger, Christian and Ławrowski, Robert Damian and Dams, Florian and Bornmann, Benjamin and Navitski, Aliaksandr and Serbun, Pavel and M{\"u}ller, G{\"u}nter and Liebetruth, Thomas and Kohlert, Dieter and Pernsteiner, Jochen and Schreier, Franz and Heerklotz, Sabrina and Heerklotz, Allwin and Boos, Alexander and Herwald, Dominik and Monkman, Gareth J. and Treiber, Daniel and Mayer, Matthias and H{\"o}rner, Eva and Bentz, Alexander and Shamonin (Chamonine), Mikhail and Johansen, S{\o}ren Peter and Reichel, Marco and Stoll, Andrea and Briem, Ulrich and Dullien, Silvia and Renkawitz, Tobias and Weber, Tim and Dendorfer, Sebastian and Grifka, Joachim and Penzkofer, Rainer and Barnsteiner, K. and Jovanovik, M. and Wernecke, P. and V{\"o}gele, A. and Bachmann, T. and Pl{\"o}tz, Martin and Schliekmann, Claus and Wels, Harald and Helmberger, Paul and Kaspar, Marcel and H{\"o}nicka, M. and Schrammel, Siegfried and Enser, Markus and Schmidmeier, Monika and Schroll-Decker, Irmgard and Haug, Sonja and Gelfert, Verena and Vernim, Matthias}, title = {Forschungsbericht 2012}, editor = {Baier, Wolfgang}, address = {Regensburg}, organization = {Ostbayerische Technische Hochschule Regensburg}, doi = {10.35096/othr/pub-783}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-7834}, pages = {64}, language = {de} } @inproceedings{LangerHausladenPrommesbergeretal., author = {Langer, Christoph and Hausladen, Matthias and Prommesberger, Christian and Ławrowski, Robert Damian and Bachmann, Michael and D{\"u}sberg, Felix and Pahlke, Andreas and Shamonin (Chamonine), Mikhail and Schreiner, Rupert}, title = {Field emission current investigation of p-type and metallized silicon emitters in the frequency domain}, series = {International Vacuum Nanoelectronics Conference (IVNC), 31st, 2018, Kyoto, Japan}, booktitle = {International Vacuum Nanoelectronics Conference (IVNC), 31st, 2018, Kyoto, Japan}, publisher = {IEEE}, doi = {10.1109/IVNC.2018.8520127}, pages = {1-2}, abstract = {We investigated two different field emitter arrays consisting of 10×10 p-type and 10×10 undoped Au-coated high aspect ratio silicon tips. The I-V characterization of the p-type sample showed a pronounced saturation for voltages higher than 500 V and a maximum emission current of 39 nA. The metallized sample revealed a FN-like emission up to several μA. The metallized and the p-type sample operating below the saturation region showed high current fluctuations of ±16\%. Whereas, the metallized sample with current regulation and the p-type sample in the saturation yielded a current stability of ±0.4\% and ±0.3\%, respectively. Investigations in the frequency domain revealed the for field emission typical 1/f-noise. By operating in the saturation region (p-type sample) or using an emission current regulation (metallized sample) the noise level was reduced by at least 20 dB. Finally, the p-type sample was illuminated by a light emitting diode to increase and modulate the emission current in the saturation region. The emission current was increased by a factor of 3.7 to 145 nA. With this configuration we emulated an unstable emission behavior and evaluated the performance of our emission current regulation circuit.}, language = {en} } @article{LohmeyerShamoninChamonineHertel, author = {Lohmeyer, Manfred and Shamonin (Chamonine), Mikhail and Hertel, Peter}, title = {Boundary conditions for the finite difference beam propagation method based on plane wave solutions of the Fresnel equation}, series = {IEEE Journal of Quantum Electronics}, volume = {33}, journal = {IEEE Journal of Quantum Electronics}, number = {2}, issn = {0018-9197}, doi = {10.1109/3.552269}, pages = {279 -- 286}, abstract = {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.}, language = {en} } @article{ShamoninChamonineLohmeyerHertel, author = {Shamonin (Chamonine), Mikhail and Lohmeyer, Manfred and Hertel, Peter}, title = {Analysis of power-dependent switching between radiatively coupled planar waveguides}, series = {Journal of Lightwave Technology}, volume = {15}, journal = {Journal of Lightwave Technology}, number = {6}, publisher = {IEEE}, address = {New York}, doi = {10.1109/50.588671}, pages = {983 -- 989}, abstract = {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.}, language = {en} } @article{LohmeyerShamoninChamonineBahlmannetal., author = {Lohmeyer, Manfred and Shamonin (Chamonine), Mikhail and Bahlmann, N. and Hertel, Peter and Dotsch, H.}, title = {Radiatively Coupled Waveguide Concept for an Integrated Magneto-Optic Circulator}, series = {MRS Online Proceedings Library}, journal = {MRS Online Proceedings Library}, number = {517}, issn = {1946-4274}, doi = {10.1557/PROC-517-519}, pages = {519 -- 524}, abstract = {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.}, language = {en} } @article{ShamoninChamonineLohmeyerHertel, author = {Shamonin (Chamonine), Mikhail and Lohmeyer, Manfred and Hertel, Peter}, title = {Directional coupler based on radiatively coupled waveguides}, series = {Applied optics (Appl. Opt.)}, volume = {36}, journal = {Applied optics (Appl. Opt.)}, number = {3}, doi = {10.1364/ao.36.000635}, pages = {635 -- 641}, abstract = {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.}, language = {en} } @misc{SorokinStepanovVasilievetal., author = {Sorokin, Vladislav V. and Stepanov, Gennady V. and Vasiliev, V. G. and Kramarenko, Elena Yu and Mayer, Matthias and Shamonin (Chamonine), Mikhail and Monkman, Gareth J.}, title = {Investigation of Dynamic Modulus and Normal Force of Magnetorheological Elastomers with Soft and Hard Magnetic Fillers}, series = {NANO 2014, July 13 - 18, 2014, Moscow ; Section 06 - Polymer, Organic and Other Soft Matter Materials}, journal = {NANO 2014, July 13 - 18, 2014, Moscow ; Section 06 - Polymer, Organic and Other Soft Matter Materials}, address = {Moscow}, language = {en} } @inproceedings{ForsterMayerRabindranathetal., author = {Forster, Eva and Mayer, Matthias and Rabindranath, Raman and Bentz, Alexander and B{\"o}se, Holger and Shamonin (Chamonine), Mikhail and Monkman, Gareth J.}, title = {Surface Control Magneto-Active Polymers (MAP)}, series = {EuroEAP 2011, First international conference on Electromechanically Active Polymer (EAP) transducers \& artificial muscles, Pisa, 8-9 June}, booktitle = {EuroEAP 2011, First international conference on Electromechanically Active Polymer (EAP) transducers \& artificial muscles, Pisa, 8-9 June}, abstract = {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.}, language = {en} } @article{RadkovskayaSydorukShamoninChamonineetal., author = {Radkovskaya, Anna A. and Sydoruk, O. and Shamonin (Chamonine), Mikhail and Shamonina, Ekaterina and Stevens, C. J. and Faulkner, Grahame and Edwards, David J. and Solymar, L.}, title = {Experimental study of a bi-periodic magnetoinductive waveguide: comparison with theory}, series = {IET Microwaves, Antennas \& Propagation}, volume = {1}, journal = {IET Microwaves, Antennas \& Propagation}, number = {1}, publisher = {IET}, issn = {1751-8733}, doi = {10.1049/iet-map:20050289}, pages = {80 -- 83}, abstract = {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.}, language = {en} } @inproceedings{MayerForsterRabindranathetal., author = {Mayer, Matthias and Forster, Eva and Rabindranath, Raman and Bentz, Alexander and B{\"o}se, Holger and Shamonin (Chamonine), Mikhail and Monkman, Gareth J.}, title = {Highly compliant Magneto-Active Polymers (MAPs)}, series = {Actuator'11, Bremen, May 2011}, booktitle = {Actuator'11, Bremen, May 2011}, language = {en} } @article{SydorukShamoninChamonineRadkovskayaetal., author = {Sydoruk, O. and Shamonin (Chamonine), Mikhail and Radkovskaya, Anna A. and Zhuromskyy, Oleksandr and Shamonina, Ekaterina and Trautner, Ralph and Stevens, C. J. and Faulkner, Grahame and Edwards, David J. and Solymar, L.}, title = {Mechanism of subwavelength imaging with bilayered magnetic metamaterials: Theory and experiment}, series = {Journal of Applied Physics}, volume = {101}, journal = {Journal of Applied Physics}, number = {7}, publisher = {AIP}, doi = {10.1063/1.2714782}, abstract = {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.}, language = {en} } @article{RadkovskayaSydorukShamoninChamonineetal., author = {Radkovskaya, Anna A. and Sydoruk, O. and Shamonin (Chamonine), Mikhail and Stevens, C. J. and Faulkner, Grahame and Edwards, David J. and Shamonina, Ekaterina and Solymar, L.}, title = {Transmission properties of two shifted magnetoinductive waveguides}, series = {Microwave and Optical Technology Letters}, volume = {49}, journal = {Microwave and Optical Technology Letters}, number = {5}, publisher = {Wiley}, doi = {10.1002/mop.22344}, pages = {997 -- 1230}, abstract = {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}, language = {en} } @inproceedings{ForsterRabindranathMayeretal., author = {Forster, Eva and Rabindranath, Raman and Mayer, Matthias and Bentz, Alexander and B{\"o}se, Holger and Shamonin (Chamonine), Mikhail and Monkman, Gareth J.}, title = {Characterization of ultra soft Magneto-Active Polymers (MAPs)}, series = {Conference proceedings / INDUCTICA 2011, Berlin, Germany, 24 - 26 May}, booktitle = {Conference proceedings / INDUCTICA 2011, Berlin, Germany, 24 - 26 May}, language = {en} } @article{SavelevGlavanBelanetal., author = {Savelev, Dmitrii V. and Glavan, Gašper and Belan, Viktoria O. and Belyaeva, Inna A. and Fetisov, Leonid Y. and Shamonin (Chamonine), Mikhail}, title = {Resonant Magnetoelectric Effect at Low Frequencies in Layered Polymeric Cantilevers Containing a Magnetoactive Elastomer}, series = {Applied Sciences}, volume = {12}, journal = {Applied Sciences}, number = {4}, publisher = {MPDI}, doi = {10.3390/app12042102}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-30637}, pages = {1 -- 13}, abstract = {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.}, language = {en} } @article{FetisovChashinSavelevetal., author = {Fetisov, Yuri K. and Chashin, Dmitri V. and Savelev, Dmitrii V. and Fetisov, Leonid Y. and Shamonin (Chamonine), Mikhail}, title = {Anisotropic Magnetoelectric Effect in a Planar Heterostructure Comprising Piezoelectric Ceramics and Magnetostrictive Fibrous Composite}, series = {Materials}, volume = {12}, journal = {Materials}, number = {19}, publisher = {MDPI}, address = {Basel}, doi = {10.3390/ma12193228}, pages = {1 -- 13}, abstract = {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.}, language = {en} } @techreport{RabindranathBoeseProbstetal., author = {Rabindranath, Raman and B{\"o}se, Holger and Probst, J{\"o}rn and Schlunck, G{\"u}nther and Mayer, Matthias and Forster, Eva and Bentz, Alexander and Shamonin (Chamonine), Mikhail and Monkman, Gareth J.}, title = {EAP mit magnetisch steuerbarer Elastizit{\"a}t zur Interaktion mit Bindegewebszellen MagElan}, address = {Regensburg}, organization = {Hochschule f{\"u}r Angewandte Wissenschaften Regensburg / Fachbereich Elektro- und Informationstechnik}, pages = {37}, language = {de} } @article{SavelevChashinFetisovetal., author = {Savelev, Dmitrii V. and Chashin, Dmitri V. and Fetisov, Leonid Y. and Shamonin (Chamonine), Mikhail and Fetisov, Yuri K.}, title = {Ceramic-Heterostructure-Based Magnetoelectric Voltage Transformer with an Adjustable Transformation Ratio}, series = {Materials}, volume = {13}, journal = {Materials}, number = {18}, publisher = {MDPI}, doi = {10.3390/ma13183981}, pages = {1 -- 13}, abstract = {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.}, language = {en} } @article{RomeisKostrovKramarenkoetal., author = {Romeis, Dirk and Kostrov, Sergei A. and Kramarenko, Elena Yu and Stepanov, Gennady V. and Shamonin (Chamonine), Mikhail and Saphiannikova, Marina}, title = {Magnetic-field-induced stress in confined magnetoactive elastomers}, series = {Soft Matter}, volume = {16}, journal = {Soft Matter}, number = {39}, publisher = {Royal Society of Chemistry}, address = {Cambridge}, doi = {10.1039/D0SM01337D}, pages = {9047 -- 9058}, abstract = {We present a theoretical approach for calculating the state of stress induced by a uniform magnetic field in confined magnetoactive elastomers of arbitrary shape. The theory explicitly includes the magnetic field generated by magnetizable spherical inclusions in the sample interior assuming a non-linear magnetization behavior. The initial spatial distribution of particles and its change in an external magnetic field are considered. This is achieved by the introduction of an effective demagnetizing factor where both the sample shape and the material microstructure are taken into account. Theoretical predictions are fitted to the stress data measured using a specifically designed experimental setup. It is shown that the theory enables the quantification of the effect of material microstructure upon introducing a specific microstructural factor and its derivative with respect to the extensional strain in the undeformed state. The experimentally observed differences between isotropic and anisotropic samples, compliant and stiff elastomer matrices are explained.}, language = {en} } @article{SnarskiiShamoninChamonineYuskevichetal., author = {Snarskii, Andrei A. and Shamonin (Chamonine), Mikhail and Yuskevich, Pavel and Savelev, Dmitrii V. and Belyaeva, Inna A.}, title = {Induced anisotropy in composite materials with reconfigurable microstructure: Effective medium model with movable percolation threshold}, series = {Physica A: Statistical Mechanics and its Applications}, volume = {560}, journal = {Physica A: Statistical Mechanics and its Applications}, number = {December}, publisher = {Elsevier}, doi = {10.1016/j.physa.2020.125170}, abstract = {In composite materials, with field-dependent restructuring of the filler material (changes in the mutual arrangement of inclusions), the presence of an external magnetic field induces anisotropy of the dielectric properties, even if the composite is isotropic in the absence of an external field. A modified effective medium approximation is proposed for the calculation of the components of effective permittivity within a class of composites with reconfigurable microstructure, where both phases (the filler and the matrix) are isotropic and the inclusions have spherical shape. The effective physical properties are calculated in the parallel and perpendicular directions to an applied field. The appearance of the anisotropy of the permittivity is simulated by the introduction of two not-equal, possibly variable (field-dependent) percolation thresholds. The implications, of the proposed theoretical approach, are demonstrated for the case of the dielectric properties of magnetoactive elastomers (MAEs). In MAEs with soft polymer matrices, the mutual arrangement of micrometer-sized magnetic inclusions can significantly change in an applied magnetic field. A reasonable agreement between theory and experiment at a measurement frequency of 1 kHz is found, and is improved in comparison to the previous models. The components of the effective permittivity tensor, characterizing the dielectric properties along the direction of the applied magnetic field and in the orthogonal direction, grow with an increasing field. This growth is more pronounced for the permittivity component in the field direction. The possible extensions of the theoretical model and future directions of research are discussed. The presented theoretical approach can be useful for the application-driven development of a number of smart materials, in particular electro- and magnetorheological gels, elastomers and fluids.}, language = {en} } @article{GlavanBelyaevaRuwischetal., author = {Glavan, Gašper and Belyaeva, Inna A. and Ruwisch, Kevin and Wollschlaeger, Joachim and Shamonin (Chamonine), Mikhail}, title = {Magnetoelectric Response of Laminated Cantilevers Comprising a Magnetoactive Elastomer and a Piezoelectric Polymer, in Pulsed Uniform Magnetic Fields}, series = {Sensors}, volume = {21}, journal = {Sensors}, number = {19}, publisher = {MDPI}, address = {Basel}, doi = {10.3390/s21196390}, pages = {1 -- 19}, abstract = {The voltage response to pulsed uniform magnetic fields and the accompanying bending deformations of laminated cantilever structures are investigated experimentally in detail. The structures comprise a magnetoactive elastomer (MAE) slab and a commercially available piezoelectric polymer multilayer. The magnetic field is applied vertically and the laminated structures are customarily fixed in the horizontal plane or, alternatively, slightly tilted upwards or downwards. Six different MAE compositions incorporating three concentrations of carbonyl iron particles (70 wt\%, 75 wt\% and 80 wt\%) and two elastomer matrices of different stiffness are used. The dependences of the generated voltage and the cantilever's deflection on the composition of the MAE layer and its thickness are obtained. The appearance of the voltage between the electrodes of a piezoelectric material upon application of a magnetic field is considered as a manifestation of the direct magnetoelectric (ME) effect in a composite laminated structure. The ME voltage response increases with the increasing total quantity of the soft-magnetic filler in the MAE layer. The relationship between the generated voltage and the cantilever's deflection is established. The highest observed peak voltage around 5.5 V is about 8.5-fold higher than previously reported values. The quasi-static ME voltage coefficient for this type of ME heterostructures is about 50 V/A in the magnetic field of approximate to 100 kA/m, obtained for the first time. The results could be useful for the development of magnetic field sensors and energy harvesting devices relying on these novel polymer composites.}, language = {en} } @article{SavelevBelyaevaChashinetal., author = {Savelev, Dmitrii V. and Belyaeva, Inna A. and Chashin, Dmitri V. and Fetisov, Leonid Y. and Romeis, Dirk and Kettl, Wolfgang and Kramarenko, Elena Yu and Saphiannikova, Marina and Stepanov, Gennady V. and Shamonin (Chamonine), Mikhail}, title = {Giant extensional strain of magnetoactive elastomeric cylinders in uniform magnetic fields}, series = {Materials}, volume = {13}, journal = {Materials}, number = {15}, publisher = {MDPI}, address = {Basel}, issn = {1996-1944}, doi = {10.3390/ma13153297}, pages = {1 -- 17}, abstract = {Elongations of magnetoactive elastomers (MAEs) under ascending-descending uniform magnetic fields were studied experimentally using a laboratory apparatus specifically designed to measure large extensional strains (up to 20\%) in compliant MAEs. In the literature, such a phenomenon is usually denoted as giant magnetostriction. The synthesized cylindrical MAE samples were based on polydimethylsiloxane matrices filled with micrometer-sized particles of carbonyl iron. The impact of both the macroscopic shape factor of the samples and their magneto-mechanical characteristics were evaluated. For this purpose, the aspect ratio of the MAE cylindrical samples, the concentration of magnetic particles in MAEs and the effective shear modulus were systematically varied. It was shown that the magnetically induced elongation of MAE cylinders in the maximum magnetic field of about 400 kA/m, applied along the cylinder axis, grew with the increasing aspect ratio. The effect of the sample composition is discussed in terms of magnetic filler rearrangements in magnetic fields and the observed experimental tendencies are rationalized by simple theoretical estimates. The obtained results can be used for the design of new smart materials with magnetic-field-controlled deformation properties, e.g., for soft robotics.}, language = {en} } @article{SavelevFetisovChashinetal., author = {Savelev, Dmitrii V. and Fetisov, Leonid Y. and Chashin, Dmitri V. and Fetisov, Yuri K. and Khon, Anastasia and Shamonin (Chamonine), Mikhail}, title = {Effects of ferromagnetic-material thickness on magnetoelectric voltage transformation in a multiferroic heterostructure}, series = {Smart Materials and Structures}, volume = {30}, journal = {Smart Materials and Structures}, number = {6}, publisher = {IOP PUBLISHING}, doi = {10.1088/1361-665X/abf6c0}, abstract = {A magnetoelectric (ME) voltage transformer is fabricated on the basis of a ferromagnetic (FM)-piezoelectric (PE) heterostructure comprising two equally thick laminated layers of an amorphous FM alloy and a piezoceramic lead zirconate-titanate layer sandwiched between them. The structure, placed inside an excitation coil, is electrically poled and magnetized in the direction of the long axis. The primary voltage is applied to the coil and the secondary voltage is measured between the electrodes of the PE material. It is shown for the first time that the change in the total thickness of magnetic layers significantly influences the transformer ' s characteristics. At the largest total thickness of FM layers of 138 mu m, the open-circuit voltage transformation ratio K has a maximum value of about 20, and the power transfer efficiency eta at a matched resistive load of about 20 k omega reaches 45\%. The variation of the control magnetic field in the range of 0-21.6 kA m(-1) makes it possible to change the voltage transformation ratio K from zero to the maximum value. A simple model allows one to calculate the dependence of the characteristics of the ME transformer on the frequency of the primary voltage, thickness of the FM layers, control magnetic field, and the load.}, language = {en} } @article{SavelevBelyaevaChashinetal., author = {Savelev, Dmitrii V. and Belyaeva, Inna A. and Chashin, Dmitri V. and Fetisov, Leonid Y. and Shamonin (Chamonine), Mikhail}, title = {Large Wiedemann effect in a magnetoactive elastomer}, series = {Journal of Magnetism and Magnetic Materials}, volume = {511}, journal = {Journal of Magnetism and Magnetic Materials}, number = {October}, publisher = {Elsevier}, doi = {10.1016/j.jmmm.2020.166969}, abstract = {Large twists of a soft tube (hollow cylinder) in helical magnetic fields are presented for the first time. Such a phenomenon is usually denoted as the Wiedemann effect. The tube is fabricated from a soft magnetoactive elastomer material with the shear modulus of about 56 kPa. The composite material comprises 80 mass\% of micrometer-sized iron particles embedded into a polydimethylsiloxane matrix. The circular magnetic field is generated by an electric current in a straight wire passing through the inner hole of the tube. The maximum value of approximately 350″/cm is observed in a longitudinal magnetic field of a few kA/m overlapped with a circumferential magnetic field of about 1.4 kA/m on the surface of the inner hole. A pronounced hysteresis in the dependence of the Wiedemann effect on the circular magnetic field is found. The ways to enhance the Wiedemann twist in magnetoactive elastomers are discussed. The observed large effect is promising for application in magnetic-field controlled torsional actuators, in particular for soft robotics.}, language = {en} } @article{SavelevFetisovChashinetal., author = {Savelev, Dmitrii V. and Fetisov, Leonid Y. and Chashin, Dmitri V. and Shabin, P. A. and Vyunik, D. A. and Fedulov, Feodor and Kettl, Wolfgang and Shamonin (Chamonine), Mikhail}, title = {Method of Measuring Deformations of Magnetoactive Elastomers under the Action of Magnetic Fields}, series = {Russian Technological Journal}, volume = {7}, journal = {Russian Technological Journal}, number = {4}, doi = {10.32362/2500-316x-2019-7-4-81-91}, pages = {81 -- 91}, language = {ru} } @misc{PershinaSavelevGlavanetal., author = {Pershina, K. V. and Savelev, Dmitrii V. and Glavan, Gašper and Chashin, Dmitri V. and Belyaeva, Inna A. and Fetisov, Leonid Y. and Shamonin (Chamonine), Mikhail}, title = {The voltage response of a structure comprising a magnetoactive-elastomer cylinder and a piezoelectric material to magnetic field step excitations}, series = {The 4th International Baltic Conference on Magnetism (IBCM 2021) : Svetlogorsk, Russia August 29 - September 2, 2021 : Book of Abstracts}, journal = {The 4th International Baltic Conference on Magnetism (IBCM 2021) : Svetlogorsk, Russia August 29 - September 2, 2021 : Book of Abstracts}, publisher = {Immanuel Kant Baltic Federal University, Kaliningrad, Russia}, pages = {182}, language = {en} } @article{DillingerWeberMayeretal., author = {Dillinger, Andrea Elisabeth and Weber, Gregor R. and Mayer, Matthias and Schneider, Magdalena and G{\"o}ppner, Corinna and Ohlmann, Andreas and Shamonin (Chamonine), Mikhail and Monkman, Gareth J. and Fuchshofer, Rudolf and Keller, Kate and Lozano, Diana C. and Clark, Abbot}, title = {CCN2/CTGF-A Modulator of the Optic Nerve Head Astrocyte}, series = {Frontiers in cell and developmental biology (Front Cell Dev Biol.)}, volume = {10}, journal = {Frontiers in cell and developmental biology (Front Cell Dev Biol.)}, publisher = {frontiers}, doi = {10.3389/fcell.2022.864433}, pages = {864433}, abstract = {In primary open-angle glaucoma (POAG), a neurodegenerative disease of the optic nerve (ON) and leading cause of blindness, the optic nerve head (ONH) undergoes marked structural extracellular matrix (ECM) changes, which contribute to its permanent deformation and to degeneration of ON axons. The remodeling process of the ECM causes changes in the biomechanical properties of the ONH and the peripapillary sclera, which is accompanied by an increased reactivity of the resident astrocytes. The molecular factors involved in the remodeling process belong to the Transforming growth factor (TGF)-β superfamily, especially TGF-β2. In previous publications we showed that TGF-β2 induced ECM alterations are mediated by Cellular Communication Network Factor (CCN)2/Connective Tissue Growth Factor (CTGF) and recently we showed that CCN2/CTGF is expressed by astrocytes of the ON under normal conditions. In this study we wanted to get a better understanding of the function of CCN2/CTGF under normal and pathologic conditions. To this end, we analyzed the glial lamina and peripapillary sclera of CCN2/CTGF overexpressing mice and studied the effect of CCN2/CTGF and increasing substratum stiffness on murine ON astrocytes in vitro. We observed enhanced astrocyte reactivity in the ONH, increased ECM protein synthesis in the peripapillary sclera and increased Ccn2/Ctgf expression in the ONH during the pathologic development in situ. CCN2/CTGF treatment of primary murine ON astrocytes induced a higher migration rate, and increase of ECM proteins including fibronectin, elastin and collagen type III. Furthermore, the astrocytes responded to stiffer substratum with increased glial fibrillary acidic protein, vimentin, actin and CCN2/CTGF synthesis. Finally, we observed the reinforced appearance of CCN2/CTGF in the lamina cribrosa of glaucomatous patients. We conclude that reactive changes in ONH astrocytes, induced by the altered biomechanical characteristics of the region, give rise to a self-amplifying process that includes increased TGF-β2/CCN2/CTGF signaling and leads to the synthesis of ECM molecules and cytoskeleton proteins, a process that in turn augments the stiffness at the ONH. Such a scenario may finally result in a vicious circle in the pathogenesis of POAG. The transgenic CTGF-overexpressing mouse model might be an optimal model to study the chronic pathological POAG changes in the ONH.}, language = {en} } @article{SavelevGlavanBurdinetal., author = {Savelev, Dmitrii V. and Glavan, Gašper and Burdin, Dmitrii A. and Belyaeva, Inna A. and Fetisov, Leonid Y. and Shamonin (Chamonine), Mikhail and Fetisov, Yuri K.}, title = {Enhancement of magnetoelectric effect in polymer composites at low resonance frequencies by operation in the transverse-transverse mode}, series = {Journal of Magnetism and Magnetic Materials}, volume = {598}, journal = {Journal of Magnetism and Magnetic Materials}, publisher = {Elsevier}, issn = {1873-4766}, doi = {10.1016/j.jmmm.2024.172020}, abstract = {The resonant direct magnetoelectric (ME) effect for a series of multilayer heterostructures comprising a magnetoactive elastomer (MAE) of different thicknesses and a commercially available piezoelectric polyvinylidene fluoride-based vibration sensor has been investigated in detail. The specimens were rigidly fixed at one end as cantilevers. The cantilevers were operated in the transverse-transverse (T-T) mode, where both magnetic and electric fields were perpendicular to the plane of a non-deformed heterostructure. It is shown that the ME voltage coefficient of considered heterostructures in the T-T mode can be about 20-fold higher than in the conventional longitudinal-transverse (L-T) mode. The highest ME voltage coefficient reached about 150 V/(Oe·cm) at the first bending oscillation mode for the sample with MAE layer thickness of 4 mm. Mechanism of the resonant ME effect in T-T mode is explained using theory of critical bending of MAE cantilevers. Magnetic fields, when the ME voltage reaches its maximum, strongly depended on the MAE layer thickness, and could be associated with the critical field, where the structure commences to strongly bend. The non-monotonous dependence of the resonance frequency of the first oscillation mode on magnetic field strength was observed. The shift of the resonance frequency in the maximum magnetic field reached up to roughly 100 \% in comparison with zero field.}, language = {en} } @article{RoghaniRomeisGlavanetal., author = {Roghani, Mehran and Romeis, Dirk and Glavan, Gašper and Belyaeva, Inna A. and Shamonin (Chamonine), Mikhail and Saphiannikova, Marina}, title = {Magnetically induced deformation of isotropic magnetoactive elastomers and its relation to the magnetorheological effect}, series = {Physical Review Applied}, volume = {23}, journal = {Physical Review Applied}, number = {3}, publisher = {American Physical Society (APS)}, issn = {2331-7019}, doi = {10.1103/PhysRevApplied.23.034041}, abstract = {Can isotropic magnetoactive elastomers (MAEs) undergo giant magnetically induced deformations and exhibit huge magnetorheological effects simultaneously? In this experimental and theoretical study, we reveal how the macroscopic deformation of MAEs relates to the process of particle restructuring caused by application of a magnetic field. For this purpose, MAE cylinders with different aspect ratios and particle loadings are studied in uniform magnetic fields. The axial deformations of the cylinders are acquired using an optical camera. A unified mean-field model proposed in previous studies is adapted to describe the transition of initially isotropic cylinders into transversely isotropic ones. This mechanical transition is caused by the rearrangement of particles into dense columnar structures aligned with the field and is believed to result in a huge magnetorheological effect. Our model however predicts less than a threefold increase in elastic moduli when evaluated along the field direction. This prediction is based on a careful examination of the shear moduli of studied MAEs and the columnar structures. A weak magnetorheological effect explains significant axial deformations measured in the field direction. A strong magnetorheological effect would hinder axial deformations due to an increase in the modulus by several orders of magnitude. Not only are the moduli and macroscopic deformations influenced by microstructure evolution, but so is the magnetization of particles, which increases as they rearrange into dense columns. With this study, we show that the unified mean-field model provides quantitative access to hidden material properties such as magnetization and stiffness in MAE samples with different shapes and evolving microstructures. Published by the American Physical Society 2025}, language = {en} } @misc{GlavanBelyaevaShamoninChamonine, author = {Glavan, Gašper and Belyaeva, Inna A. and Shamonin (Chamonine), Mikhail}, title = {On the Piezomagnetism of Magnetoactive Elastomeric Cylinders in Uniform Magnetic Fields: Height Modulation in the Vicinity of an Operating Point by Time-Harmonic Fields [Data set]}, doi = {10.5281/zenodo.13834054}, language = {en} } @misc{GlavanBelyaevaShamoninChamonine, author = {Glavan, Gašper and Belyaeva, Inna A. and Shamonin (Chamonine), Mikhail}, title = {Multiferroic Cantilevers Containing a Magnetoactive Elastomer: Magnetoelectric Response to Low-Frequency Magnetic Fields of Triangular and Sinusoidal Waveform [Data set]}, doi = {10.5281/zenodo.14651784}, language = {en} } @article{GlavanBelyaevaShamoninChamonine, author = {Glavan, Gašper and Belyaeva, Inna A. and Shamonin (Chamonine), Mikhail}, title = {Multiferroic Cantilevers Containing a Magnetoactive Elastomer: Magnetoelectric Response to Low-Frequency Magnetic Fields of Triangular and Sinusoidal Waveform}, series = {Sensors}, volume = {22}, journal = {Sensors}, number = {10}, publisher = {MDPI}, address = {Basel}, doi = {10.3390/s22103791}, pages = {1 -- 17}, abstract = {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.}, language = {en} } @article{KrieglJezeršekKravanjaetal., author = {Kriegl, Raphael and Jezeršek, Matija and Kravanja, Gaia and Hribar, Luka and Mukhi, Soham and Kokot, Gašper and Drevenšek-Olenik, Irena and Shamonin (Chamonine), Mikhail}, title = {Tunable rebound of millimeter-sized rigid balls by magnetic actuation of elastomer-based surface microstructures}, series = {Smart Materials and Structures}, volume = {33}, journal = {Smart Materials and Structures}, number = {6}, publisher = {IOP Publishing}, doi = {10.1088/1361-665X/ad41a9}, abstract = {A novel method for controlling the rebound behavior of small balls made of Al2O3 with a radius of 2.381 mm is presented. It uses different types of micro-structured surfaces of soft magnetoactive elastomers. These surfaces were fabricated via laser micromachining and include fully ablated surfaces as well as micrometer-sized lamellas with a fixed width of 90 µm, height of 250 µm and three different gap sizes (15, 60 and 105 µm). The lamellas can change their orientation from edge-on to face-on configuration according to the direction of the external magnetic field from a permanent magnet. The orientation of the external magnetic field significantly influences the rebound behavior of the balls, from a coefficient of restitution e of to < 0.1. The highest relative change in the coefficient of restitution between zero field and face-on configuration of is observed for lamellas with a gap of 60 µm. Other characteristics of the ball rebound such as the penetration depth into an Magnetoactive elastomer and the maximum deceleration are investigated as well. The proposed method does not require a constant power supply due to the use of permanent magnets. It may find novel applications in the field of impact engineering.}, language = {en} } @misc{GlavanBelyaevaShamoninChamonineetal., author = {Glavan, Gašper and Belyaeva, Inna A. and Shamonin (Chamonine), Mikhail and Ruwisch, Kevin and Wollschl{\"a}ger, Joachim}, title = {Magnetoelectric Response of Laminated Cantilevers Comprising a Magnetoactive Elastomer and a Piezoelectric Polymer, in Pulsed Uniform Magnetic Fields [Data set]}, doi = {10.5281/zenodo.14652152}, language = {en} } @misc{GlavanBelyaevaShamoninChamonine, author = {Glavan, Gašper and Belyaeva, Inna A. and Shamonin (Chamonine), Mikhail}, title = {Transient Response of Macroscopic Deformation of Magnetoactive Elastomeric Cylinders in Uniform Magnetic Fields [Data set]}, doi = {10.5281/zenodo.10679499}, language = {en} } @article{GlavanBelyaevaShamoninChamonine, author = {Glavan, Gašper and Belyaeva, Inna A. and Shamonin (Chamonine), Mikhail}, title = {Transient Response of Macroscopic Deformation of Magnetoactive Elastomeric Cylinders in Uniform Magnetic Fields}, series = {Polymers}, volume = {16}, journal = {Polymers}, number = {5, Special Issue Magnetic Polymer Composites: Design and Application II}, publisher = {MDPI}, address = {Basel, Schweiz}, issn = {2073-4360}, doi = {10.3390/polym16050586}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-71067}, pages = {17}, abstract = {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.}, language = {en} } @article{StrausKravanjaKriegletal., author = {Straus, Izidor and Kravanja, Gaia and Kriegl, Raphael and Shamonin (Chamonine), Mikhail and Drevenšek-Olenik, Irena and Jezeršek, Matija and Kokot, Gašper}, title = {Laser Micromachining for Polymer Surface Topography Designt}, series = {JoVE journal : engineering}, journal = {JoVE journal : engineering}, publisher = {JoVE}, doi = {10.3791/68126}, pages = {15}, abstract = {Soft magnetoactive elastomers (MAEs) are smart materials that respond to external magnetic fields by dynamically altering their mechanical properties. They are composed of magnetically responsive microparticles embedded within a soft polymer matrix, exhibiting an effective shear modulus of up to 100 kPa. In recent decades, MAEs' bulk properties have been successfully exploited for applications such as dynamic vibration damping, vibration sensing, and actuation in soft robotics. Recent research has shifted to their surface properties, revealing promising results on tunable surface features such as roughness, adhesion, and wetting. Even the transport of small solid and fluid objects was demonstrated. The associated surface effects can be significantly enhanced through the precise engineering of surface topography. In this article, an efficient laser micromachining technique, with a resolution of 15 µm, is presented, which enables rapid prototyping of MAE surfaces. It allows the creation of various complex shapes and offers functionality beyond the one achievable with traditional molding techniques. Additionally, the approach is versatile and can be applied to any polymer that sufficiently absorbs the laser light. As an example, a lamellar surface micro-pattern fabrication process and its characterization by optical and scanning electron microscopies are shown. Its response to a magnetic field is demonstrated. The technique provides a flexible and fast solution for optimizing polymer surface design across a wide range of applications.}, language = {en} }