Magnetoelastic instability in soft thin films

TL;DR

This paper investigates how ferromagnetic particles in soft elastic films enable magnetic actuation and switching, revealing magnetoelastic effects useful for soft robotics and microfabrication.

Contribution

It introduces experimental and modeling insights into magnetoelastic instabilities in soft thin films, demonstrating switchable actuation via magnetic field manipulation.

Findings

Subcritical pitchfork bifurcation observed in beam shape

Magnetoelastic effects depend on field strength and orientation

Successful demonstration of a magnetic soft robotic octopus

Abstract

Ferromagnetic particles are incorporated in a thin soft elastic matrix. A lamella, made of this smart material, is studied experimentally and modeled. We show herein that thin films can be actuated using an external magnetic field applied through the system. The system is found to be switchable since subcritical pitchfork bifurcation is discovered in the beam shape when the magnetic field orientation is modified. Strong magnetoelastic effects can be obtained depending on both field strength and orientation. Our results provide versatile ways to contribute to many applications from the microfabrication of actuators to soft robotics. As an example, we created a small synthetic octopus piloted by an external magnetic field.