Transition of Magnetic Field Due to Geometry of Magneto-Active Elastomer Microactuator With Nonlinear Deformation

This is the authors' abstract. We don't add key points for this paper.

Magneto-active elastomer is widely used for microactuator/microsensor application. For optimization of the actuation performance of the magneto-active elastomer, it is crucial to characterize its magnetic field distribution and mechanical behavior. By a novel multiphysics model, this paper thus investigates the transition between the uniform and non-uniform magnetic fields and the field-induced nonlinear deformation, due to reversible variation of the geometric size of the magneto-active elastomer from infinite to finite one. In this paper, both the elastomer and its surrounding medium are covered in the computational domain, where the Maxwell stress over the elastomer-surrounding interface is considered as an additional mechanical boundary, and the nonlinear magnetization included in a proposed free energy density. After validation of the present model with both the published theoretical and experimental works, it is concluded that increasing the geometric size of the magneto-active elastomer leads to a more uniform magnetic field, and thus the elastomer undergoes the transition from the non-uniform to uniform magnetic fields, if its size increases to a critical point, such as aspect ratio of 12.4 for the present cylindrical magneto-active elastomer.