Fabrication of H-shaped structure magnetorheological elastomer film for enhancing electrical properties by AC electric field

The limited electronic applications of magnetorheological elastomers (MREs), polymer composites with carbonyl iron powder (CIP), are addressed in this study with a groundbreaking methodology. By utilizing a noncontact AC electric field, CIP manipulation at low concentrations (0.5–5 vol%) leads to the formation of conductive pathways within MREs. The resulting H-shaped structure exhibits columnar conductive pathways along the film’s thickness and interconnected pathways throughout the matrix, effectively reducing both volume and surface resistivity. Insights into the formation process are gained through real-time observations and numerical simulations. Experimental measurements reveal a remarkable reduction in volume and surface resistivity, achieving three and two orders of magnitude reduction, respectively, in 5 vol% H-shaped structure MREs. Remarkably, the H-shaped structure MREs display exceptional magneto-resistive and magneto-rheological behavior. Variations in surface resistance and resonant frequency occur with changing magnetic fields, with surface resistance decreasing by up to 89.6% (510 mT) and resonant frequency decreasing by up to 49.05% (300 mT). The efficacy of electric field-treated H-shaped structure MRE films is confirmed for practical applications in self-sensing tunable vibration absorbers. This research presents an innovative approach to enhance MRE conductivity, introducing a significant advancement in electronic functionality that opens doors to cutting-edge applications.