Magneto-active polymers (MAPs) can undergo rapid and noticeable deformation through external wireless magnetic stimulation, offering a possibility to develop potential applications such as in actuators, flexible micro-grippers, soft robots, etc. In this paper, a theoretical model is presented to depict the relationship between nonlinear deformation and the external mechanical load applied on cylindrical samples in the presence of magnetic fields generated by an electromagnet. The geometrical and electromagnetic properties of the electromagnet are explicitly modeled in COMSOL Multiphysics based on the measured data. Furthermore, a finite element model is constructed to obtain detailed information (such as strain field), which cannot be obtained in experiments. The theoretical and simulation results fit quite well with the experimental results, showing the accuracy of the model construction. The proposed designing approach and model provide guidelines for researchers to enrich the applications of MAPs.

中文翻译：

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圆柱形软磁致动器非均匀轴向磁场致变形研究

磁活性聚合物 (MAP) 可以通过外部无线磁刺激发生快速且显着的变形，这为开发潜在应用提供了可能，例如在执行器、柔性微夹具、软机器人等方面的应用。在本文中，提出了一个理论模型来描述非线性变形与在存在电磁体产生的磁场的情况下施加在圆柱形样品上的外部机械载荷之间的关系。在 COMSOL Multiphysics 中，基于测量数据对电磁体的几何和电磁特性进行了明确建模。此外，构建有限元模型以获得实验无法获得的详细信息（如应变场）。理论和仿真结果与实验结果吻合较好，表明了模型构建的准确性。所提出的设计方法和模型为研究人员丰富 MAP 的应用提供了指导。