Cobalt particles have been introduced as a filler due to the advantages of embedding their magnetic and electrical properties in magnetorheological elastomer (MRE). In the present research, the rheology and resistance of MRE are experimentally evaluated. Isotropic and anisotropic MRE samples containing silicone rubber and cobalt particles were fabricated. The magnetic properties of MRE are conducted using a vibrating sample magnetometer (VSM). The morphological aspects of MRE are observed by using field emission scanning electron microscopy (FESEM) and characterized by energy-dispersive X-ray spectroscopy (EDX). Rheological properties under various magnetic field strengths were measured for the magnetic field, strain amplitude, and frequency sweep test by using a parallel-plate rheometer. Subsequently, the resistance of MRE is tested under different applied forces and magnetic fields. The MRE storage modulus depicted an enhancement in field-dependent modulus across all the applied magnetic fields. The electrical resistance generated from the sample can be manipulated by external magnetic fields and mechanical loads. The conductivity of MRE is due to the existence of cobalt arrangements observed by FESEM. By introducing cobalt as filler and obtaining satisfactory results, the study might open new avenues for cobalt to be used as filler in MRE fabrication for future sensing applications.

The effect of graphite (Gr) based magnetorheological elastomer (MRE) on resistance is experimentally evaluated in this research. Isotropic and anisotropic MRE samples are prepared by utilizing Gr as a filler in MRE fabrication. The physical, rheological and resistance properties of Gr-MRE are investigated and compared to those of typical or conventional MREs without Gr. Morphological aspects of Gr-MRE are characterized by field emission scanning electron microscope (FESEM), scanning electron microscope and energy dispersive x-ray spectroscopy, while rheological properties are evaluated using a rheometer. Subsequently, the resistance properties are investigated by using the designated test-rig. Based on the resistance evaluation, a curve describing the relationship of resistance ( R ) under different applied forces ( F ) and different magnetic fields ( B ) are established and plotted. Moreover, it is observed that the FESEM images shows the presence of Gr fractions, which contributes to the conductivity property of MRE. It is also observed that with the addition of Gr, the rheological and conductivity properties such as the storage modulus and resistance response are improved parallel with the increment of magnetic field. It is also demonstrated that the addition of Gr in MRE can contribute to the use of force detection in sensing devices.

In most studies, carbonyl iron particles were merged with carbon-based particles such as graphite or carbon black particles as fillers to enhance the electrical properties of magnetorheological elastomers (MREs). These combined fillers can be replaced by using a single material in order to reduce brittleness due to the high amount of composition. Therefore, in this research, cobalt particles having dual properties, magnetic and electrical, have been employed as a filler in MRE. A total of three anisotropic MREs containing 53, 60, and 67 wt% of cobalt were fabricated through the mixing process method. The characterization related to morphological and magnetic properties of MRE samples was analyzed by using field emission scanning electron microscopy and vibrating sample magnetometer. Then, the rheological properties of the MRE in various strengths of magnetic field intensity between 0 and 0.8 T were conducted by using a rheometer. Afterward, the effect of the cobalt on the electrical properties was investigated and compared with different applied forces towards the MRE. The outcome showed that the rheological and electrical properties of MRE were improved with the increase of cobalt content embedded in the silicone matrix. Higher cobalt content in MRE contributed to a higher magnetorheological (MR) effect and simultaneously lower the electrical resistivity. Therefore, the addition of cobalt particles as a filler in MRE is a great potential to be applied as sensors.