Design of a smart piezoelectric actuator based on a magnetorheological elastomer

In this paper, design of a novel smart actuator with controllable characteristics based on a magnetorheological elastomer (MRE) is introduced. The actuator is composed of a piezoelectric layer bonded cantilever, whose free end is attached by an MRE layer. By adjusting the magnetic field applied to the MRE, the dynamic characteristics of the beam can be controlled due to the MRE's characteristics of field-dependent shear modulus. Thus, the characteristics of the actuator can be improved by adjusting the load curve and the resonant frequency of the actuator. Simulations on such field-controllable behavior of the actuator through introducing mass as the mechanical load are conducted. The variable load curves indicate that the driving force increases with the applied magnetic field under the same output velocity. The relative change of the resonant frequency of the actuator is found to be adjusted up to 30% by the applied magnetic field. This field-controlled resonant frequency opens the way to keep the actuator at high energy conversion rate through adjusting the applied magnetic field since the resonant state relates to the maximum energy conversion rate. This approach may lead to a novel design of a smart actuator which can work adaptively with the working condition.