4.6 Article

Effects of soft and hard magnetic particles on the mechanical performance of ultra-soft magnetorheological elastomers

Journal

SMART MATERIALS AND STRUCTURES
Volume 31, Issue 6, Pages -

Publisher

IOP Publishing Ltd
DOI: 10.1088/1361-665X/ac6bd3

Keywords

magnetorheological elastomers (MREs); magneto-mechanics; experimental characterisation; hard-magnetics MRE; multifunctional materials; magnetic properties

Funding

  1. European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme [947723]
  2. Ministerio de Ciencia, Innovacion y Universidades, Spain [FPU19/03874]
  3. Comunidad de Madrid [CM 2018 - 2018-T2/IND-9992]
  4. EPSRC Impact Acceleration Award [EP/R511614/1]
  5. [MCIN/ AEI /10.13039/501100011033]
  6. [PID2020-117894GA-I00]

Ask authors/readers for more resources

Magnetorheological elastomers (MREs) can change their mechanical properties and shape in response to external magnetic stimuli. Recent studies have shown the potential of MREs with a soft matrix and soft-magnetic particles for significant mechanical stiffening. This paper presents an alternative solution using hard-magnetic MREs to achieve sustained stiffening responses without the need for a constant external magnetic field.
Magnetorheological elastomers (MREs) mechanically respond to external magnetic stimuli by changing their mechanical properties and/or changing their shape. Recent studies have shown the great potential of MREs when manufactured with an extremely soft matrix and soft-magnetic particles. Under the application of an external magnetic field, such MREs present significant mechanical stiffening, and when the magnetic field is off, they show a softer response, being these alternative states fully reversible. Although soft-magnetic particles are suitable for their high magnetic susceptibility, they require the magnetic actuation to remain constant in order to achieve the magneto-mechanical stiffening. Here, we present an alternative solution based on hard-magnetic MREs to provide stiffening responses that can be sustained along time without the need of keeping the external magnetic field on. To this end, we manufacture novel extremely soft hard-magnetic MREs (stiffness in the order of 1 kPa) and characterise them under magneto-mechanical shear and confined magnetic expansion deformation modes, providing a comparison framework with the soft-magnetic counterparts. The extremely soft nature of the matrix allows for easily activating the magneto-mechanical couplings under external magnetic actuation. In this regard, we provide a novel approach by setting the magnetic actuation below the fully magnetic saturating field. In addition, free deformation tests provide hints on the microstructural transmission of torques from the hard-magnetic particles to the viscoelastic matrix, resulting in macroscopic geometrical effects and intricate shape-morphing phenomena.

Authors

I am an author on this paper
Click your name to claim this paper and add it to your profile.

Reviews

Primary Rating

4.6
Not enough ratings

Secondary Ratings

Novelty
-
Significance
-
Scientific rigor
-
Rate this paper

Recommended

No Data Available
No Data Available