# Magnetostrictive Effect of Magnetorheological Elastomers Controlled by Magneto-Mechanical Coupling at the Mesoscopic Scale

## TL;DR

This study explores how magnetorheological elastomers change shape under magnetic fields, revealing how their structure affects performance for potential use in smart devices.

## Contribution

A correction factor for magnetic dipole theory and mesoscopic analysis of magnetostriction in MREs are introduced.

## Key findings

- Magnetostriction depends on the angle between particle chains and magnetic field direction.
- Linearity of particle chains positively correlates with magnetostriction.
- Maximum theoretical and experimental magnetostrictive elongation and compression values were achieved.

## Abstract

Magnetorheological elastomers (MREs) have attracted considerable attention in high-precision sensing and intelligent control due to their responsive sensitivity. The magnetostrictive properties of MREs excited by magneto-mechanical coupling at the mesoscopic scale show broad application potential but have not yet been fully elucidated. In this study, the magnetostrictive properties were investigated at the mesoscopic scale through theoretical modeling, numerical simulation and experimental research. A correction factor was introduced to address the limitations of conventional magnetic dipole theory under near-field conditions, thereby providing a rational theoretical explanation of magnetostrictive behavior. Visualization analysis was performed using the finite element method (FEM). Subsequently, MREs were prepared under various solidified magnetic fields, and their performance was validated through scanning electron microscopy (SEM) and a laser displacement sensor. The results demonstrated that magnetostriction is determined by the relative angle between the particle chain and the magnetic field direction. The linearity of the particle chain was found to be positively correlated with magnetostriction. The maximum theoretical and experimental magnetostrictive elongations reached 0.9% and 0.565%, respectively, while the maximum theoretical and experimental magnetostrictive compression reached 2.77% and 1.81%, respectively. This work provides significant scientific insights into the magneto-mechanical energy conversion mechanism and contributes to the development of magnetostrictive instruments.