Structure-Property-Actuation Evaluation of Magneto-Responsive Micropillar Arrays with Shape Fixability via Covalent Adaptable Networks

Magneto-responsive micropillar arrays offer a promising platform for microfabrication, enabling precise, non-contact reconfiguration of surface morphologies under an external magnetic field. However, the magnetically deformed shapes are typically reversible, as the micropillars return to their original shape upon the removal of the magnetic field. In this presentation, we introduce a novel strategy to achieve robust fixation of magnetically deformed shapes in micropillar arrays by employing a matrix with covalent adaptable networks. Additionally, we systematically evaluated the influence of magnetic particle concentration on the mechanical properties and magnetic responsiveness of the micropillar arrays. Increasing the magnetic particle concentration enhances the magneto-responsiveness but also increases the elastic modulus, resulting in higher bending stiffness. This trade-off between magnetization and mechanical stiffness determines the magnitude of magnetic actuation in the micropillars. By optimizing the concentration of magnetic particles embedded in the matrix, we achieved a maximum bending actuation at a particle concentration of 20 vol%. The covalent adaptable networks facilitate the formation of adaptable chemical bonds, enabling the fixation of magnetically induced deformations through a thermomechanical process. Our study demonstrate not only provides optimized magnetic actuation through the evaluation of magnetic particle concentration but also enables reconfigurable shape fixation of micropillar arrays using covalent adaptable networks.This approach offers significant potential for advancing the functionality of magneto-responsive surfaces in applications requiring stable, reconfigurable microstructures.