磁性颗粒在磁场作用下的运动特性研究

Study on the Movement Characteristics of Magnetic Particles in Magnetic Field

热超材料自提出以来就备受关注,但受限于材料热导率的局部调控,人工制备存在困难。磁场偏转颗粒结合3D打印是一种新型的三维热超材料制备手段,但需要进一步完善磁场偏转颗粒理论。本文在磁性颗粒运动模型的基础上引入二面角,使其能预测颗粒的偏转时间。随后采用显微镜观测的方法验证改进模型的准确性,测试结果与理论结果吻合较好。研究发现:颗粒偏转时间随着磁场强度变大,胶体黏度变小而变短,但与磁场频率是非线性关系。

Thermal metamaterials have attracted much attention since their introduction,but are limited by the local adjustment of material thermal conductivity.Therefore,nowadays it is difficult to fabricate metamaterial manually.Magnetic field deflection particles combined with 3D printing is a new manufacture method of three-dimensional thermal metamaterial.However,the theory of magnetic field deflection particles needs to be further improved.In this paper,the dihedral angle is introduced on the basic magnetic particle motion model so that it can predict the particle deflection time.Then the accuracy of the improved model was verified by microscopic observation and the test results are in good agreement with the theoretical results.It is found that the particle deflection time becomes shorter as the magnetic field strength becomes larger and the viscosity of the colloid becomes shorter,but it is non-linear with the magnetic field frequency.