This study designs an all-in-one module of a tunable vibration absorber (TVA) using magnetorheological elastomer (MRE) considering easy installation in a plug-and-play concept on an actual industrial plant. The proposed system is designed to overcome several limitations on a typical system composed of an electromagnet and MRE TVA, such as environmental robustness, bulky size, high power consumption and complex installation on an actual plant. The designed TVA module contains sensors for MRE tuning control feedback, an energy-efficient magnetic field density generator, MRE and absorber mass. A novel but simple magnetic field generator is proposed using a small brushless DC gimbal motor and permanent magnets to reduce unnecessary energy consumption for long-term operation. The TVA module is designed so that it can be easily attached to an existing target system, such as a linear compressor. Using the embedded sensors in the module, it can automatically tune the MRE stiffness adaptively to the disturbance vibration on the target system. The prototype performance is validated with experiments showing that it can provide approximately 94% of stiffness change and 58% of vibration suppression for disturbance in the frequency range of 51.6-71.9 Hz.

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.

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