Designing a system to manipulate micro magnetic beads and cells

Abstract

Magnetic tweezers are able to manipulate cells or biomolecules for various applications and measurements. In this study, an electromagnetic micromanipulator is designed, modeled and controlled for single magnetic bead manipulations. Electromagnetic tweezers are capable of controlling micron sized superparamagnetic particles with the help of appropriate control mechanism. Magnetic particles can be functionalized with receptors in order to capture the target biomolecules, and conjugated particles can be moved to a certain place by using an external magnetic field. Magnetic monopole and magnetic circuit approaches are used to model the dynamic equation of the magnetic system. An offset current based feedback linearizing is devised to ensure wide range of movement conditions with zero steady-state error. Image based algorithm is developed in order to find the position of the single particle. Numerical simulations are carried out in order to validate the derived model and the control system. The designed magnetic system is able to apply magnetic forces in the range of 1-100 pN to control a magnetic particle of 1 to 10 micrometer of diameter with a current less than 1 A. The magnetic micromanipulator system can be used for single cell separation, and biosensor applications.