Railway Actuator Made of Magnetic Elastomers and Driven by a Magnetic Field

Umehara, Yasuhiro; Yamanaga, Yusuke; Akama, Shota; Kato, Shunsuke; Kamoshita, Shogo; Kawai, Mika; Mitsumata, Tetsu

doi:10.3390/polym10121351

Cited by 12 publications

(11 citation statements)

References 22 publications

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“…When a magnetic field is applied to a magnetic elastomer, the elasticity increases due to the chain structure formation (restructuring) of magnetic particles, which is called the magnetorheological (MR) effect. So far, we have investigated the MR effect for polyurethane-based magnetic elastomers and found that bimodal magnetic elastomers with magnetic and nonmagnetic particles exhibit a significant MR effect compared with monomodal magnetic elastomers [9][10][11][12][13].…”

Section: Introductionmentioning

confidence: 99%

Efficient Chain Formation of Magnetic Particles in Elastomers with Limited Space

et al. 2020

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The magnetic response of the storage modulus for bimodal magnetic elastomers containing magnetic particles with a diameter of 7.0 μm and plastic beads with a diameter of 200 μm were investigated by varying the volume fraction of plastic beads up to 0.60 while keeping the volume fraction of the magnetic particles at 0.10. The storage modulus at 0 mT for monomodal magnetic elastomers was 1.4 × 104 Pa, and it slightly increased with the volume fraction of plastic beads up to 0.6. The storage modulus at 500 mT for bimodal magnetic elastomers at volume fractions below 0.25 was constant, which was equal to that for the monomodal one (=7.9 × 104 Pa). At volume fractions of 0.25–0.40, the storage modulus significantly increased with the volume fraction, showing a percolation behavior. At volume fractions of 0.40-0.60, the storage modulus was constant at 2.0 × 105 Pa, independently of the volume fraction. These results indicate that the enhanced increase in the storage modulus was caused by the chain formation of the magnetic particles in vacancies made of plastic beads.

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Section: Introductionmentioning

confidence: 99%

Efficient Chain Formation of Magnetic Particles in Elastomers with Limited Space

et al. 2020

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“…The ordering of microdomains increases the membrane conductivity to about 50%. The effect of a constant magnetic field on elastomers was observed by Umehara et al [ 36 ]. They produced a mono-link using bimodal magnetic elastomers, which showed marked changes in the elastic modulus under the influence of magnetic fields.…”

Section: Introductionmentioning

confidence: 99%

“…A special edition of the Polymers journal was devoted to this issue. That special edition was intended to document the latest advances in the use of magnetic fields for polymer processing and the production of functional polymer systems [ 33 , 34 , 35 , 36 , 37 ]. A group of German scientists have invented a polymer with shape memory which can be triggered by a magnetic field.…”

Section: Introductionmentioning

confidence: 99%

Modification of the Properties of Polymer Composites in a Constant Magnetic Field Environment

et al. 2021

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In this paper, polymer composites based on polylactide (PLA) and epoxy resin (Epidian 5) were studied in terms of the influence of magnetic induction on their changes in physicochemical properties. The composites contained admixtures in the form of magnetite (Fe3O4) and crystalline cellulose (Avicel PH-1010) in the amount of 10%, 20%, and 30% by weight and starch in the amount of 10%. The admixtures of cellulose and starch were intended to result in the composites becoming biodegradable biopolymers to some extent. Changes in physical and chemical properties due to the impact of a constant magnetic field with a magnetic induction value B = 0.5 T were observed. The changes were observed during tests of tensile strength, bending, impact strength, water absorbency, frost resistance, chemical resistance to acids and bases, as well as through SEM microscopy and with studies of the composition of the composites that use the EDS method and of their structure with the XRD method. Based on the obtained results, it was found that the magnetic induction value changes the properties of composites. This therefore acts as one method of receiving new alternative materials, the degradation of which in the environment would take far less time.

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“…It is attributed to the embedded magnetic particles in the foam as a matrix phase. In comparison with other MR solid material, such as MR elastomer (Umehara et al, 2018), MR foam has a unique porous and cellular structure that forms chemically by trapping gases in the liquid phase during the foaming process (Cain et al, 2013). Its porous structure has not only entitled the material to be low in density and physically lightweight (Davino et al, 2012) but also contributes to a great cushioning effect to absorb vibrations and shock impact (Linde et al, 1972).…”

Section: Introductionmentioning

confidence: 99%

Stiffness enhancement of magnetorheological foam by structural modification using silica nanoparticles additive

et al. 2022

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Magnetorheological (MR) foam is a newly developed porous smart material that is able to change its properties continuously, actively, and reversibly in response to controllable external magnetic stimuli. Unfortunately, the stiffness or also known as storage modulus of MR foam is still rather low and insufficient, in the range of below 100 kPa only, due to weak interparticle interaction between CIPs and the foam matrix, which consequently restricts the potential of MR foam to be used in future sensor applications or in other semi-active devices. Therefore, the aim of this research is to enhance the structural and storage modulus of MR foam by adding silica nanoparticles as an additive. Consequently, MR foam samples with different compositions of silica nanoparticles in the range of 0–5 wt% were prepared via an in situ method. The rheological properties were tested under an oscillatory shear mode with the absence and presence of magnetic fields using a rheometer, with the input parameters of strains between 0.001% and 10% and range of magnetic flux density between 0 and 0.73 T for a magnetic field sweep test. The rheological findings show that with the addition of silica nanoparticles, particularly at 4 wt%, have enhanced the storage modulus of MR foam by 260%, which attributed to the highest stiffness from 45 to 162 kPa. Meanwhile, the change of storage modulus under the influence of magnetic fields (0 T–0.73 T) somehow showed small increment, about ∆1 kPa for each concentration of silica nanoparticles in MR foams, due to non-magnetic behavior of silica. The morphological characteristics of MR foams were described by an elemental analysis carried out by a using variable pressure scanning electron microscope (VPSEM) equipped with energy dispersive x-ray spectroscopy (EDX). The micrographs demonstrated large open-cell pores for MR foam, while MR foam with silica nanoparticles exhibited more closed-cell pores, associated with the enhancement of its storage modulus. It indicates that the silica nanoparticles have encouraged well dispersion of the particles in the foam matrix, which improved and strengthened the microstructure of MR foams through formation of silane coupling bonds of silica in the filler-matrix structure. Overall, incorporation of silica nanoparticles as an additive in the MR foam could provide advantage in enhancing the structure and mechanical properties of MR foam, for various future smart devices.

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Railway Actuator Made of Magnetic Elastomers and Driven by a Magnetic Field

Cited by 12 publications

References 22 publications

Efficient Chain Formation of Magnetic Particles in Elastomers with Limited Space

Efficient Chain Formation of Magnetic Particles in Elastomers with Limited Space

Modification of the Properties of Polymer Composites in a Constant Magnetic Field Environment

Stiffness enhancement of magnetorheological foam by structural modification using silica nanoparticles additive

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