Use of magnetorheological elastomer for smart piezoelectric power actuator design and signal processing

This paper reviews the investigations of introducing magnetorheological elastomer (MRE)-based technologies to the design of smart electronic devices. Piezoelectric power actuators are required to operate at a resonant state in order to deliver maximum mechanical energy to loads. Owing to the field-dependent dynamic flexural rigidity of MRE-based structures, power actuators utilizing such structures exhibit the capability of compensating the change of the loads and keeping the resonant frequency at a fixed value. Four kinds of bender configurations for such smart actuators will be reviewed. They are: a cantilever suspended by an MRE patch at its free end, a single-layer MRE-based sandwich beam surface-bonded by piezoelectric patches, a multi-layer MRE-based sandwich beam surface-bonded by piezoelectric patches, and an inserts reinforced MRE-based sandwich beams surface-bonded by piezoelectric patches. Their driving capability and field-controllable capability are discussed in a detail. In addition, MRE-based structures are extended to propose linear time-variant systems for time-frequency signal processing. The system function is presented and the Wigner-Ville distribution is used to analyze the time-frequency distribution of the time-delayed response of the system. The system is proved to be a damped-vibration system with field-controllable resonant frequencies. Due to the fieldcontrollable time-frequency pattern of the time-delayed response, the system can be used for data encryption and signal modulation.