On the magnetic actuation of accordion structures comprised of magneto-active elastomers

Magneto-active elastomers (MAEs) have garnered significant attention for their versatility in adaptive structures and soft robotics. This study investigates the behavior of soft (SM)- and hard-magnetic (HM) MAE accordion structures under external magnetic fields, focusing on the effects of demagnetizing fields. To the best of our knowledge, the SM MAEs have been employed in these structures for the first time. Three different configurations with two or four MAEs were examined: HM structure with an initial angle of 0 ∘ (flat structure), and SM structures with initial horizontal angles of 20 ∘ and 45 ∘ (zig-zag structures). Each structure was fabricated using a silicone base with MAE patches glued on it and tested under varied magnetic fields. The results reveal that hard magnetic structures exhibit uniform deformation with minimal rotational effects, while SM structures demonstrate significant angular rotation, flipping or flattening at low starting angles due to demagnetizing field-induced torques. The 20 ∘ SM configuration showed more pronounced angular response than the 45 ∘ configuration, emphasizing the influence of initial starting angle. This work contributes to the understanding of magnetic field interactions in MAE structures and provides a foundation for designing programmable, magnetically controlled actuators for advanced engineering applications.