Analysis of Electrical Resistance and Impedance Change of Magnetorheological Gels with DC and AC Voltage for Magnetometer Application

Abstract

Magnetorheological gel (MRG) is a smart material that can change its stiffness property by external magnetic field and has been applied as a smart rubber in suppressing vibration. Recent studies show that the electrical resistance of MRG also can be affected with external magnetic field. Thus, this study aimed to conduct analysis on MRG resistance variation due to external magnetic field with DC and AC input voltage. With an DC input voltage, the resistance change due to magnetic field was modeled. In addition, the capacitance variation of the material was observed. The impedance of MRG due to AC input voltage was analyzed and was observed that the impedance of MRG was affected by both the magnetic field and the input frequency. With the experiment data, the impedance modeling of MRG in frequency domain was derived. Based on experiment results, the performance and limitation of MRG as a magnetometer sensor are discussed.

Electrical and Magnetodielectric Properties of Magneto-Active Fabrics for Electromagnetic Shielding and Health Monitoring

“…However, for a fixed value of the quantity of microfibers, the initial distance between the magnetic dipoles remains constant, and this leads to an increase of the equivalent capacitance ( Figure 5 ), and respectively to a decrease of the equivalent resistance ( Figure 9 ). Note that the effects shown in Figure 4 and Figure 9 are obtained by using much lower quantities of microfibers, as compared with the quantities of carbonyl iron microparticles used to obtain similar effects in References [ 26 , 27 , 33 , 35 , 36 , 39 , 40 , 41 ].…”

“…In the presence of the magnetic field, the fibers are aligned along the magnetic field lines, as shown in Figure 7 . Formation of such aggregates inside the liquid/viscoelastic matrices or fibers lead to electrical properties which are sensibly changed by the magnetizable phase even at low concentrations, and are also sensibly influenced by an external magnetic field intensity [ 26 , 27 , 31 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 ].…”

“…For magnetic materials consisting from ferri/ferro-magnetic nano/micro-particles dispersed in liquid/elastic matrices, as the MAFs obtained here, the equivalent electrical resistance and capacitance arise due to the interaction between magnetic dipoles from the chains and due to the concentration of the magnetizable phase [ 33 , 35 , 36 , 39 , 40 ]. Along the magnetic dipoles chains, oriented in the direction of , and chosen in such a way that it coincides with axis Ox, the equivalent electrical capacitance between two neighbouring dipoles, and the equivalent resistance between dipoles are given by [ 26 ] , and respectively , where x is the distance between center-of-masses of dipoles, is the electrical conductivity, and d is the average diameter of the magnetic dipoles, here the thickness of the dipoles consisting from mFe.…”

Machine Learning-Based Predictions on the Self-Heating Characteristics of Nanocomposites with Hybrid Fillers

“…During the self-heating tests, the surface temperature and current flowing through the specimens were recorded via a K-type thermocouple and a data logger (Agilent Technologies 34972A), respectively. After the test, the recorded current was converted to the electrical resistance (R) according to the Ohm's law as described in previous studies [31,32]. The normalized resistance (R/R 0 ) is obtained by dividing R by the initial resistance (R 0 ), which is measured immediately after the voltage is applied [6].…”

Evaluation of (CNT@CIP)-Embedded Magneto-Resistive Sensor Based on Carbon Nanotube and Carbonyl Iron Powder Polymer Composites

“…Expeditious advancements of conductive polymeric composites (CPCs) have been gaining attention due to their high applicability, such as multi-functional sensors [1][2][3], electrical-heating composites [4][5][6], electromagnetic interference shielding composites [7][8][9], and other electronic devices [10,11]. Various kinds of conductive fillers including carbonbased fillers such as graphene, and carbon nanotubes and magnetic powder have been used to fabricate the CPCs due to their high electrical conductivity [11][12][13]. Among the conductive fillers, carbon nanotube (CNTs) have been popular conductive fillers due to their remarkable electrical and mechanical properties and high compatibility with polymer matrix.…”