Development of an Enhanced Electromagnetic Actuation System with Enlarged Workspace

Electromagnetic actuation is an emerging wireless control approach for manipulating magnetic microparticles for diverse minimally invasive therapy and diagnosis. This paper presents an enhanced electromagnetic manipulation system with an enlarged workspace, which is achieved by both the parametric design and the quantitative modeling of generated magnetic field of the system. The parametric design aims to characterize the influence of electromagnet parameters, such as position, radius, and height of cores on the generated electromagnetic field, so that the electromagnet specifications of the developed system can achieve a large workspace, while possessing the desired magnetic field flux density (MFFD) and gradient. With this design, the workspace of the developed prototype can reach a spherical volume with a diameter of 110 mm, the MFFD can reach 100 mT, and the gradient of MFFD can reach 2.5 T/m. The spatial distribution of electromagnetic field is quantitatively modeled using the finite-element method. Based on this model, a unit electromagnetic field distribution database for a 3-D grid of points is established. Such database enables the effective manipulation of microparticles in a considerably large workspace rather than only small central area. Experiments of manipulating paramagnetic microparticles in both 2-D and 3-D scenarios are performed to demonstrate the effectiveness of the designed system.