Dexterous magnetic manipulation of conductive non-magnetic objects
Dexterous magnetic manipulation of conductive non-magnetic objects
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DOI：
10.1038/s41586-021-03966-6
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发表时间：
2021-10-21
期刊：
影响因子：
64.8
通讯作者：
Abbott, Jake J.
中科院分区：
文献类型：
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作者：
Pham, Lan N.;Tabor, Griffin F.;Abbott, Jake J.
时变磁场可以用来操纵导电的非磁性物体的位置和方向。铁磁性物体的双向磁操纵是公认的，根据物体的几何形状，可能有三到六个自由度(1)。对于不包含可观数量的铁磁材料但确实包含导电材料的物体来说，需要非接触式灵巧操作。时变磁场在导电材料(2-4)中产生涡流，由于涡流与磁场的相互作用而产生力和扭矩。该现象以前被用来诱导阻力以减少物体通过静电场(5-8)时的运动，或者使用动态场(9-11)在单一方向上向物体施加力，但还没有被用来执行已经用铁磁物体演示的对导电物体的灵活操纵类型。在这里，我们展示了通过使用多个旋转的磁偶极子磁场，以六个自由度操纵导电物体是可能的。利用量纲分析(12)，结合多物理数值模拟和实验验证，我们表征了在旋转磁偶极子磁场中导电球体上产生的力和力矩。利用得到的模型，我们在模拟和物理实验中进行了灵活的操作。
Time-varying magnetic fields can be used to manipulate the position and orientation of conductive non-magnetic objects.Dexterous magnetic manipulation of ferromagnetic objects is well established, with three to six degrees of freedom possible depending on object geometry(1). There are objects for which non-contact dexterous manipulation is desirable that do not contain an appreciable amount of ferromagnetic material but do contain electrically conductive material. Time-varying magnetic fields generate eddy currents in conductive materials(2-4), with resulting forces and torques due to the interaction of the eddy currents with the magnetic field. This phenomenon has previously been used to induce drag to reduce the motion of objects as they pass through a static field(5-8), or to apply force on an object in a single direction using a dynamic field(9-11), but has not been used to perform the type of dexterous manipulation of conductive objects that has been demonstrated with ferromagnetic objects. Here we show that manipulation, with six degrees of freedom, of conductive objects is possible by using multiple rotating magnetic dipole fields. Using dimensional analysis(12), combined with multiphysics numerical simulations and experimental verification, we characterize the forces and torques generated on a conductive sphere in a rotating magnetic dipole field. With the resulting model, we perform dexterous manipulation in simulations and physical experiments.