Magnetostriction Enhancement in Midrange Modulus Magnetorheological Elastomers for Sensor Applications

Abstract

Magnetorheological elastomer (MRE), which is capable of exhibiting magnetostriction in the presence of a magnetic field, has a great potential to be used for the development of sensor devices. Unfortunately, to date, many works focused on studying low modulus of MRE (less than 100 kPa) which can hamper their potential application in sensors due to short lifespan and low durability. Thus, in this work, MRE with storage modulus above 300 kPa is to be developed to enhance magnetostriction magnitude and reaction force (normal force). To achieve this goal, MREs are prepared with various compositions of carbonyl iron particles (CIPs), in particular, MRE with 60, 70 and 80 wt.% of CIP. It is shown that both the magnetostriction percentage and normal force increment are achieved as the concentration of CIPs increases. The highest magnetostriction magnitude of 0.075% is obtained with 80 wt.% of CIP, and this increment is higher than that of moderate stiffness MRE developed in the previous works. Therefore, the midrange range modulus MRE developed in this work can copiously produce the required magnetostriction value and potentially be implemented for the design of forefront sensor technology.

Transient Response of Macroscopic Deformation of Magnetoactive Elastomeric Cylinders in Uniform Magnetic Fields

“…In recent years, there is growing interest in the investigation of magnetic-field-induced macroscopic deformations of an intriguing class of polymer-based ferromagnetic composite materials, known as magnetorheological or magnetoactive elastomers (MAEs) [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 ]. In general, MAE comprise micro- or nanometer-sized ferromagnetic particles embedded into a soft elastomer matrix [ 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 ].…”

“…In general, MAE comprise micro- or nanometer-sized ferromagnetic particles embedded into a soft elastomer matrix [ 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 ]. The reason for this surge of interest is determined by much higher deformations of MAEs (longitudinal strain up to 10 −2 –10 −1 ) in technically feasible magnetic fields (few hundred kA/m) in comparison to conventional (pure metals and alloys) magnetostrictive materials (strain up to about ) [ 22 ], which makes them promising for potential applications as magnetically controlled soft actuators in soft robotics [ 23 , 24 ] and magnetic field sensors [ 10 ]. The change in the shape or the dimensions of a solid magnetic material induced by a change in its magnetic state is commonly designated as magnetostriction [ 25 ].…”

“…[ 8 ] used helicoidal-shaped particles from a Fe-Co alloy embedded into a soft elastomer matrix to achieve a giant strain of 3731 ppm at an unprecedently low volume fraction of particles of just 3.4 vol%. Tasin et al [ 10 ] studied the MAEs of the moderate stiffness (shear storage modulus above 300 kPa) and reached the maximum strain of ≈7.5 × in a highly filled MAE with 80 wt% of iron (Fe). Glavan et al [ 11 ] investigated soft MAE cylinders and achieved the highest reported strain of ≈0.35 for an MAE sample with 75 wt% of iron and an aspect ratio of 0.2.…”

Surface Modification of Magnetoactive Elastomers by Laser Micromachining

“…Bulk, as well as surface properties of MAEs, can be manipulated with external magnetic fields, which causes restructuring of a magnetic filler in a compliant elastic matrix. This rearrangement of magnetic inclusions induces changes in the elastic moduli [13][14][15][16][17][18][19][20][21] and contributes to magnetostriction [22][23][24][25][26][27][28][29][30][31][32][33][34]. It is also known that an external magnetic field affects such surface properties of MAEs as adhesion [35][36][37][38][39][40], friction [41,42], roughness [39,[43][44][45][46], wettability [40,47,48], and optical [49,50].…”