Magnetorheological elastomers: Experimental and modeling aspects

Abstract : Magnetorheological elastomers (MREs) are active composite materials that deform under a magnetic field because they are made of a soft elastomer matrix filled with magnetizable micrometric particles. Along with short response times and low magnetic inputs, not only do MREs alter their viscoelastic properties and stiffness in response to external magnetic fields but they can also undergo very high deformation states. While the former effect can be exploited in controllable-stiffness devices, the latter is of interest for haptic devices such as tactile interfaces for the visually impaired. In the perspective of developing a persistent tactile MRE surface exhibiting reversible and large out-of-plane deformations, the first part of this work focuses on the fabrication of MREs that can sustain large deformations. In particular, we determine the critical strain threshold up to which the interfacial adhesion between particles and matrix is ensured. In the second part of this work, an experimental setup is developed in order to characterize MRE composites under coupled magneto-mechanical mechanical loading. The experiments conducted on this setup will eventually serve as an input for a continuum model describing magneto-mechanical coupling.