2.3.1. Silicone Rubber

Unlike other organic rubbers, the silicone rubber (SR) has both organic and inorganic properties due to Si-O bonding. Because of these characteristics, heat resistance, its electrical insulation, abrasion resistance, and chemical stability are superior to general organic rubber [24,26]. Therefore, it has been used in many industrial areas including food processing and medical devices. Because of these advantages, it has also been used as a matrix of MREs. Among many SRs, polydimethylsiloxanes (PDMSs) were adopted as the matrix of MRE. Due to the chemical neutrality and stability of PDMS system, it has also a good adhesive property with metal. PDMS rubbers have the advantage of being able to cure at low temperatures and fast curing at high temperatures. In addition, the precursor has a low shear viscosity, making it easy to manufacture MREs [27,68,69]. Xu et al. [70] manufactured a PDMS based MRE and studied the movement mechanism of magnetic particles in the MRE according to the magnetic field. Li and Nakano [71] have reported the mechanical and MR e ffects of the CI and PDMS matrix base MRE.
