Modeling and Experimental Characterization of an Untethered Magnetic Micro-Robot

Abstract

Here we present the control, performance and modeling of an untethered electromagnetically actuated magnetic micro-robot. The microrobot, which is composed of neodymium-iron-boron with dimensions 250 1m 1 130 1m 1 10 1m, is actuated by a system of six macroscale electromagnets. Periodically varying magnetic fields are used to impose magnetic torques, which induce stick-slip motion in the micro-robot. These magnetic forces and torques are incorporated into a comprehensive dynamic model, which captures the behavior of the micro-robot. By pivoting the micro-robot about an edge, non-planar obstacles with characteristic sizes comparable to the robot length can be surmounted. Actuation is demonstrated on several substrates with different surface properties, in a fluid environment, and in a vacuum. Observed micro-robot translation speeds can exceed 10 mm s 21 .

Magnetic Actuation Based Motion Control for Microrobots: An Overview

“…The OctoMag system enables five DoF wireless magnetic control of a fully-untethered microrobot, including three DoF of translation (3T) and two DoF of rotation (2R). Similar to OctoMag, electromagnetic systems consisting of multiple independently-controlled electromagnets are widely used for magnetically-actuated microrobots, such as the MiniMag with eight electromagnets used by Schuerle et al [60], a system with six electromagnets developed by Pawashe et al [61], a system with eight electromagnets arranged in a different way used by Diller et al [62] and And et al [54] and a system with four electromagnets used by Khalil et al [42]. These kinds of electromagnetic systems enable motion control with a high DoF.…”

Evaluation of actuation compatibility and homogeneities for MRI-powered ferromagnetic sphere

“…In previous literature, [14,15] some groups have discussed the principle of ferromagnetic sphere in gradient field. With my knowledge, when a ferromagnetic materials embedded in a free space that magnetized to convert the magnetic energy into mechanical energy.…”

Electromagnetic Steering of a Magnetic Cylindrical Microrobot Using Optical Feedback Closed-Loop Control

“…[15] The use of charge-coupled device (CCD) array cameras, along with microscopic lenses, is another approach to achieve optical feedback to determine the position of a microrobot. [17][18][19] This optical system has been proposed for assisting in eye surgery for minimally invasive intraocular operations. [19] In addition, Bergeles et al [20] developed a model to localize a microrobot inside a human eye using a camera.…”