title: Design and Modeling of a 3-D Magnetic Actuator for Magnetic Microbead Manipulation.
abstract: This paper presents the design, implementation, modeling, and analyses of a hexapole magnetic actuator that is capable of 3-D manipulation of a magnetic microbead. The magnetic actuator employs six sharp-tipped magnetic poles placed in hexapole configuration, six actuating coils, and a magnetic yoke. The magnetic poles concentrate the magnetic flux generated by the coils to the workspace, resulting in a high magnetic field with a large field gradient for magnetic force generation on the magnetic microbead. A lumped-parameter magnetic force model is then established to characterize nonlinearity of the magnetic force exerting on the magnetic microbead with respect to the applied currents to the coils and the position dependence of the magnetic force in the workspace. The force generation capability of the designed system is then explored using the force model. Moreover, an inverse force model is derived and its effect on the magnetic actuation capability is investigated. The inverse force model facilitates the implementation of a feedback control law to stabilize and control the motion of a magnetic microbead. Experimental results in terms of the magnetic force in relation to stable motion control of a magnetic microbead are used to validate the force model.
authors.affiliation: Department of Mechanical and Aerospace Engineering, The Ohio State University, Columbus, OH 43210 USA. He is now with the GE Global Research Center, Niskayuna, NY 12309 USA ( zhang.473@osu.edu ).
authors.forename: Zhipeng
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: Department of Mechanical and Aerospace Engineering, The Ohio State University, Columbus, OH 43210 USA ( menq.1@osu.edu ).
authors.forename: Chia-Hsiang
authors.initials: CH
authors.lastname: Menq
keywords: 3-D magnetic actuation; Magnetic circuit; magnetic force model; magnetic micromanipulation