Zhang Chuan Wei, Hao Xing Peng, Zou Weifeng, Zhu Zhixin, Hu Jia Yu, Hou Li Xin, Xu Si Rui, Luo Zhen, Yan Yichen, Sarabia Andrea, Litwak Andrea, Xu Shili, Wang Zhi Jian, He Ximin, Zheng Qiang, Wu Zi Liang
Ministry of Education Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310058, China.
Department of Materials Science and Engineering, University of California, Los Angeles, Los Angeles, CA 90095, USA.
Sci Adv. 2025 Jun 27;11(26):eadw0500. doi: 10.1126/sciadv.adw0500.
Magnetic soft actuators with reprogrammable deformations have gained substantial attention due to their adaptability for various applications. However, achieving precise and local reorientation of magnetic particles remains challenging. Here, we present a strategy to locally tailor the viscoelasticity of magnetic supramolecular hydrogels, facilitate reorientation of the embedded magnetic particles, and enable reprogrammable magnetoactuated deformation and locomotion of the composite gels. The magnetic hydrogels are facilely prepared by mixing neodymium-iron-boron particles with an aqueous poly(acrylic acid--acrylamide) solution, which spontaneously forms supramolecular network with carboxylic-ferric ion coordinates as physical cross-links. This network enables dynamic control of viscoelasticity by localized laser heating, which reduces the pinning force of gel matrix and allows for reorientation of magnetic particles under a modest magnetic field. We demonstrate that the same hydrogel sheet can be reprogrammed to exhibit various complex deformations and locomotion. This versatile approach to developing magnetic hydrogels with adaptive responses offers exciting potential for soft robotics and biomedical devices.
具有可重新编程变形的磁性软致动器因其对各种应用的适应性而受到广泛关注。然而，实现磁性颗粒的精确局部重新定向仍然具有挑战性。在此，我们提出一种策略，可局部调整磁性超分子水凝胶的粘弹性，促进嵌入磁性颗粒的重新定向，并实现复合凝胶的可重新编程磁驱动变形和移动。通过将钕铁硼颗粒与聚丙烯酸 - 丙烯酰胺水溶液混合，轻松制备磁性水凝胶，该溶液自发形成以羧基 - 铁离子配位作为物理交联的超分子网络。这种网络通过局部激光加热实现对粘弹性的动态控制，从而降低凝胶基质的钉扎力，并使磁性颗粒在适度磁场下能够重新定向。我们证明，同一水凝胶片可重新编程以展现各种复杂的变形和移动。这种开发具有自适应响应的磁性水凝胶的通用方法为软机器人技术和生物医学设备提供了令人兴奋的潜力。
