Bending of hard-magnetic soft beams: A finite elasticity approach with anticlastic bending

Abstract

Soft-materials that respond to external stimuli are very useful for application in soft robotics, stretchable electronics, biomedical applications etc. Recent times have seen a surge in research of magnetically activated polymers due to their wide range of material properties, applications and important features such as non-contact, fast and non-invasive actuation. Furthermore, these applications ask for Hard-magnetic particles, which can retain their magnetization even after the applied magnetic field has been removed. In this work, we focus on developing a thermodynamically-consistent analytical solution to the large bending deformation of hard-magnetic soft hyperelastic beams under the influence of an applied uniform magnetic field. The principal stress in the cross-sections, which arise due to anticlastic bending were also calculated. Lastly, a Prony series approximation was used to encapsulate the time dependent response of the material properties of the soft beam. The model was verified by comparing the results to previously developed experimental, numerical and analytical results.