Investigation of Dynamic Behaviors of Flexible Beam Actuators Based on Magnetic Polymers

Abstract

This study investigates the dynamic properties of Magneto-Rheological Elastomers (MRE) with hard magnetic particles used as bending actuators under an alternating magnetic field. As earlier studies demonstrated that a dispersion of hard magnetic particles in polymeric materials, aligned in a preferred orientation, cause rotational motion in the sample when a magnetic field is applied perpendicularly to the magnetization direction of the particles. They focused on static responses of MREs with hard magnetic particles. The primary goal of this study is to characterize the dynamic behavior of a flexible bending actuator based on MREs under alternating magnetic fields. In this study, samples from a previous study, consisting of barium hexaferrite particles at 30% concentrations by volume, were tested. A C-shaped electromagnet was constructed to apply alternating magnetic fields along the length of the sample. By securing only one end of the sample to the electromagnet, the sample is free to bend similar to a cantilever beam. Using this setup, the tip displacement of the sample was recorded using a precision load cell and a laser displacement sensor under various input magnetic field strengths and frequencies. The results show that increasing the voltage output or the magnetic field strength increases the displacement of the sample. The results also show that, as the frequency of the sinusoidal voltage input increases, the amplitude of the tip displacement of the sample decrease.