Study on movement mechanism of magnetic particles in silicone rubber-based magnetorheological elastomers with viscosity change

This paper investigated the effects of petroleum-based oils (PBOs) as a dispersing aid on the physicochemical characteristics of natural rubber (NR)-based magnetorheological elastomers (MREs). The addition of PBOs was expected to overcome the low performance of magnetorheological (MR) elastomers due to their inhomogeneous dispersion and the mobility of magnetic particles within the elastomer matrix. The NR-based MREs were firstly fabricated by mixing the NR compounds homogeneously with different ratios of naphthenic oil (NO), light mineral oil (LMO), and paraffin oil (PO) to aromatic oil (AO), with weight percentage ratios of 100:0, 70:30, 50:50, and 30:70, respectively. From the obtained results, the ratios of NO mixed with low amounts of AO improved the material physicochemical characteristics, such as thermal properties. Meanwhile, LMO mixed the AO led to the best results for curing characteristics, microstructure observation, and magnetic properties of the MREs. We found that the LMO mixed with a high content of AO could provide good compatibility between the rubber molecular and magnetic particles due to similar chemical structures, which apparently enhance the physicochemical characteristics of MREs. In conclusion, the 30:70 ratio of LMO:AO is considered the preferable dispersing aid for MREs due to structural compounds present in the oil that enhance the physicochemical characteristics of the NR-based MREs.

Download Full-text

Magnetorheological Hybrid Elastomers Based on Silicone Rubber and Magnetorheological Suspensions with Graphene Nanoparticles: Effects of the Magnetic Field on the Relative Dielectric Permittivity and Electric Conductivity

International Journal of Molecular Sciences ◽

10.3390/ijms20174201 ◽

2019 ◽

Vol 20 (17) ◽

pp. 4201 ◽

Cited By ~ 4

Author(s):

Bica ◽

Bunoiu

Keyword(s):

Magnetic Field ◽

Dielectric Permittivity ◽

Silicone Rubber ◽

Silicone Oil ◽

Relative Dielectric Permittivity ◽

Magnetorheological Elastomers ◽

Magnetorheological Suspensions ◽

Alternating Electric Field ◽

Graphene Nanoparticles ◽

The Magnetic Field

Hybrid magnetorheological elastomers (hMREs) were manufactured based on silicone rubber, silicone oil, carbonyl iron microparticles, graphene nanoparticles and cotton fabric. Using the hMREs, flat capacitors (FCs) were made. Using the installation described in this paper, the electrical capacitance and the coefficient of dielectric losses of the hMREs were measured as a function of the intensity of the magnetic field superimposed over an alternating electric field. From the data obtained, the electrical conductivity, the relative dielectric permittivity and magnetodielectric effects are determined. It is observed that the obtained quantities are significantly influenced by the intensity of the magnetic field and the amount of graphene used.

Download Full-text

Performance of Magnetorheological Elastomer Based Silicone/SAIB

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.772.61 ◽

2018 ◽

Vol 772 ◽

pp. 61-65

Author(s):

Muntaz Hana Ahmad Khairi ◽

Saiful Amri Mazlan ◽

Ubaidillah ◽

Siti Aishah Abdul Aziz ◽

Norhiwani Mohd Hapipi

Keyword(s):

Rheological Properties ◽

Silicone Rubber ◽

Carbonyl Iron ◽

Excitation Frequency ◽

Rubber Matrix ◽

Iron Particles ◽

Magnetorheological Elastomer ◽

Magnetorheological Elastomers ◽

Mr Effect ◽

Strain Dependent

This study introduces a sucrose acetate isobutyrate (SAIB) as an additive of magnetorheological elastomers (MREs) to be added in silicone rubber matrix and carbonyl iron particles (CIPs) as their filler. The CIPs were fixed at 60 wt% and two types of MREs sample were fabricated which are isotropic and anisotropic. Rheological properties related to shear storage modulus were measured using a rheometer (MCR 302, Anton Paar). The experimental results demonstrated that the magnetorheological (MR) effect of anisotropic MREs-based Silicone/SAIB was 126 % as compared to isotropic MREs-based Silicone/SAIB, 64%. The fabricated MREs samples were frequency and strain dependent. The relative MR effect for both samples showed decreasing trend with the increment of strain amplitude and excitation frequency.

Download Full-text

MONITORING INTERPARTICLE DISTANCE IN MAGNETORHEOLOGICAL COMPOSITES

International Journal of Modern Physics B ◽

10.1142/s0217979207045773 ◽

2007 ◽

Vol 21 (28n29) ◽

pp. 4868-4874

Author(s):

G. BOSSIS ◽

E. COQUELLE ◽

C. NOEL ◽

F. GIULIERI ◽

A. M. CHAZE

Keyword(s):

Magnetic Field ◽

Liquid Crystal ◽

Energy Dissipation ◽

Viscoelastic Properties ◽

Magnetic Particles ◽

Interparticle Distance ◽

Magnetorheological Elastomer ◽

Magnetorheological Elastomers ◽

Magnetic Spheres ◽

The Creation

We describe two different systems, the first one based on a magnetorheological elastomer and the second one on magnetic particles inside a liquid crystal. In both system we manage to have chain structures with particles that are not in contact. The effect of the gap between particles on the viscoelastic properties are studied. We show in particular how in magnetorheological elastomers, the energy dissipation is closely related to the creation and the motion of cavities in the gap between the particles. In liquid crystal chaining of particles can occur without applying a magnetic field. This happens if the anchoring of liquid crystal on the surface of the particles is homeotropic. We demonstrate how the combination of elastic defects and of a magnetic field allow to obtain microscopic springs made of a pair of magnetic spheres.

Download Full-text

Sensing Behavior of Magnetorheological Elastomers

Journal of Mechanical Design ◽

10.1115/1.3160316 ◽

2009 ◽

Vol 131 (9) ◽

Cited By ~ 49

Author(s):

Xiaojie Wang ◽

Faramarz Gordaninejad ◽

Mert Calgar ◽

Yanming Liu ◽

Joko Sutrisno ◽

...

Keyword(s):

Magnetic Field ◽

Electrical Properties ◽

Magnetic Particles ◽

External Stimulus ◽

Magnetorheological Elastomer ◽

Polymer Medium ◽

Mechanical Loads ◽

Magnetorheological Elastomers ◽

Impedance Response ◽

Ferromagnetic Particles

A magnetorheological elastomer (MRE) is comprised of ferromagnetic particles aligned in a polymer medium by exposure to a magnetic field. The structures of the magnetic particles within elastomers are very sensitive to the external stimulus of either mechanical force or magnetic field, which result in multiresponse behaviors in a MRE. In this study, the sensing properties of MREs are investigated through experimentally characterizing the electrical properties of MRE materials and their interfaces with external stimulus (magnetic field or stress/strain). A phenomenological model is proposed to understand the impedance response of MREs under mechanical loads and magnetic fields. Results show that MRE samples exhibit significant changes in measured values of impedance and resistance in response to compressive deformation, as well as the applied magnetic field.

Download Full-text

Fabrication and Characterization of Isotropic and Anisotropic Magnetorheological Elastomers, Based on Silicone Rubber and Carbonyl Iron Microparticles

Polymers ◽

10.3390/polym10121343 ◽

2018 ◽

Vol 10 (12) ◽

pp. 1343 ◽

Cited By ~ 13

Author(s):

Jesús Puente-Córdova ◽

M. Reyes-Melo ◽

Luis Palacios-Pineda ◽

Imperio Martínez-Perales ◽

Oscar Martínez-Romero ◽

...

Keyword(s):

Experimental Data ◽

Silicone Rubber ◽

Carbonyl Iron ◽

Loss Modulus ◽

Rubber Matrix ◽

Zener Model ◽

Magnetorheological Elastomers ◽

In Series ◽

Fractional Zener Model

This article focuses on studying the rheological behavior of isotropic and anisotropic magnetorheological elastomers (MREs), made of carbonyl iron microparticles dispersed into a silicone–rubber matrix by considering 20 and 30 wt % of microparticles. Sample sets were prepared for each composition, with and without the application of an external magnetic field. Experimental measurements of the material rheology behavior were carried out by a shear oscillatory rheometer at constant temperature, to determine both the shear storage modulus (G′) and shear loss modulus (G′′) for all characterized samples. Then, experimental data collected from the isotropic and the anisotropic material samples were used to plot the Cole-Cole diagrams to quantify the interfacial adhesion between carbonyl iron microparticles and the silicone-rubber matrix. Furthermore, the Fractional Zener Model (FZM) with two spring-pots in series is used for quantitative analysis of collected experimental data.

Download Full-text

Simulation Study on the Motion of Magnetic Particles in Silicone Rubber-Based Magnetorheological Elastomers

Mathematical Problems in Engineering ◽

10.1155/2019/8182651 ◽

2019 ◽

Vol 2019 ◽

pp. 1-11

Author(s):

Zhiqiang Xu ◽

Heng Wu ◽

Qiuliang Wang ◽

Liyin Yi ◽

Jun Wang

Keyword(s):

Magnetic Field ◽

Silicone Rubber ◽

Applied Magnetic Field ◽

Magnetic Particles ◽

Equations Of Motion ◽

Viscous Force ◽

The Finite Element Method ◽

Magnetic Field Model ◽

Magnetorheological Effect

Magnetorheological elastomer (MRE) is an intelligent composite material and has been widely used in various fields such as vibration reduction and sensing. MRE has an excellent magnetorheological effect through the chaining of its internal magnetic particles. Current studies on MREs mainly focus on the preparation of materials and characterization of mechanical properties. However, very few studies have been conducted on the mechanism of magnetic particle motion during MRE curing. Based on the silicone rubber-based MRE, the motion mechanism of magnetic particles during curing was explored through numerical simulation. First, we analyzed the magnetic force and viscous force of magnetic particles in MRE and discussed the equations of motion of magnetic particles under applied magnetic field. Further, we established a uniform magnetic field model through the finite element method and simulated the motion of two magnetic particles under the magnetic field. Finally, we discussed the effects of particle distribution angles, particle radii, applied magnetic field strength, and distance between particles on particle velocity and displacement. The results show that the distance between particles has the greatest influence on the motion of magnetic particles, and the size of the distance between particles will affect the contact time of the particles, thus affecting the chain formation of magnetic particles in the MRE.

Download Full-text

Anisotropic Silicone Rubber Based Magnetorheological Elastomer with Oil Silicone and Iron Microparticles

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.190.645 ◽

2012 ◽

Vol 190 ◽

pp. 645-648 ◽

Cited By ~ 10

Author(s):

I. Bica ◽

Maria Balasoiu ◽

A.I. Kuklin

Keyword(s):

Magnetic Field ◽

Elastic Properties ◽

Silicone Rubber ◽

Longitudinal Magnetic Field ◽

Dipole Approximation ◽

Continuous Linear ◽

Magnetorheological Elastomer ◽

Magnetorheological Elastomers ◽

Young Module ◽

Linear Body

Results on anisotropic magnetorheological elastomers magnetoelasticity are presented and discussed. In the dipole approximation, and considering the MRE as a continuous linear body, the effects of magnetic field on its main elastic properties (linear deformations and Young module) are investigated. Experimental evidences that the compression of the cylindrical bar is influenced by the intensity of the longitudinal magnetic field and the Young module of the MRE sample increases with the intensity H of the longitudinal magnetic field are obtained and the results discussed.

Download Full-text

Folding Actuation and Locomotion of Novel Magneto-Active Elastomer (MAE) Composites

Volume 1: Development and Characterization of Multifunctional Materials; Modeling, Simulation and Control of Adaptive Systems; Integrated System Design and Implementation ◽

10.1115/smasis2013-3222 ◽

2013 ◽

Cited By ~ 9

Author(s):

Paris von Lockette ◽

Robert Sheridan

Keyword(s):

Magnetic Field ◽

Barium Ferrite ◽

Magnetic Particles ◽

Flat Surface ◽

Iron Particles ◽

Soft Magnetic ◽

Magnetorheological Elastomers ◽

Vibration Attenuation ◽

Magnetically Aligned ◽

Mechanical Actuation

Magneto-active elastomers (also called magnetorheological elastomers) are most often used in vibration attenuation application due to their ability to increase in shear modulus under a magnetic field. These shear-stiffening materials are generally comprised of soft-magnetic iron particles embedded in a rubbery elastomer matrix. More recently researchers have begun fabricating MAEs using hard-magnetic particles such as barium ferrite. Under the influence of uniform magnetic fields these hard-magnetic MAEs have shown large deformation bending behaviors resulting from magnetic torques acting on the distributed particles and consequently highlight their ability for use as remotely powered actuators. Using the magnetic-torque-driven hard-magnetic MAE materials and an unfilled silicone elastomer, this work develops novel composite geometries for actuation and locomotion. MAE materials are fabricated using 30% v/v 325 mesh barium ferrite particles in Dow Corning HS II silicone elastomers. MAE materials are cured in a 2T magnetic field to create magnetically aligned (anisotropic) materials as confirmed by vibrating sample magnetometry (VSM). Gelest optical encapsulant is used as the uniflled elastomer material. Mechanical actuation tests of cantilevers in bending and of accordion folding structures highlight the ability of the material to perform work in moderate, uniform fields of μ0H = 150 mT. Computational simulations are developed for comparison. Folding structures are also investigated as a means to produce untethered locomotion across a flat surface when subjected to an alternating field similar to scratch drive actuators; geometries investigated show promising results.

Download Full-text