Assume a Spherical Cube: Bounding the Force and Torque Induced on a Conductive Nonmagnetic Cube by a Rotating Magnetic Dipole

A time-varying magnetic field induces electric currents in a conductive object, which in turn induces a force–torque wrench on the object that is not due to ferromagnetism. Prior work empirically modeled the wrench induced in a solid sphere by a rotating magnetic dipole (RMD) field, and then used this model to perform contactless manipulation using multiple RMD field sources, motivated by application in on-orbit satellite servicing and space-debris capture. In this letter, we measure the induced wrench on a conductive, nonferromagnetic cube—which, unlike on a sphere, is not invariant to orientation—in six canonical configurations, and we compare it to that of a sphere with identical volume. Results show that such a spherical model provides a reasonable orientation-invariant approximation of a cube. Further, the induced wrench can be bounded by considering the induced wrenches on spheres with $\pm 15\%$ volume.