*4.2. Vibration Isolator*

The smart MRE isolation system, whose sti ffness and damping characteristics di ffer according to the external environment, has been implanted in several studies to overpower the drawbacks of conventional rubber isolators. Many studies have been researched on MRE isolators. Opie et al. [140]

researched room temperature vulcanized SR to produce a vertically tunable isolator, which increased the resonance peak attenuation and load speed up to 16% and 30%, respectively. Liao et al. [141] fabricated MRE isolator with a voice coil motor to reduce the transfer rate up to 70 %. Li et al. [142,143] reported a lateral laminated MRE bearing for large scale building isolation, which includes multilayer thin MRE sheets attached on to multilayer thin steel plates. The maximum lateral stiffness that can be changed due to different excitation currents is up to 1630%. In addition, Xing et al. [144], similar bearing structure to Li et al. [143], but for seismic mitigation in a bridge superstructure. The resonance frequency has increased from 10 Hz to 20 Hz, which applies to seismic mitigation. The four MRE isolator embedded together, which is used for the bridge monitoring equipment is given in Figure 10b.

**Figure 10.** Schematic diagram of (**a**) MRE vibration absorber (Reprinted with permission from [145] and (**b**) MRE isolation system [146].
