Micromagnetic Manipulators - Ferromagnetic Microwire Systems for Diffusion and Separation of Para and Dia- magnetic Particles in GradientMagnetic Field

Abstract

Micromagnetic manipulators to control and manage the dynamics of micro and nanoparticles are widely used in medicine, physics, and biology. In this paper, we proposed a number of concepts of targeted use of ferromagnetic microwires for para and dia-magnetic objects manipulation. The microwires are produced in a biocompatible glass shell by Taylor-Ulitovsky method and exhibit tunable magnetic properties. They have the ability to create high gradient magnetic fields due to specific composition of the ferromagnetic core, magnetic domain structure and micron dimensions. For various experimental tasks, the optimal configuration of ferromagnetic microwires in the system and the direction of the wire magnetization are selected. A point trap for paramagnetic particles is formed by an individual wire with an axial magnetization. The wires magnetized along diameter are a source of linearly situated magnetic poles and help to realize a fast redistribution of even weakly paramagnetic particles. Due to a camel-back profile of the magnetic potential, created by a pair of closely spaced wires with orthogonal magnetization they act as effective diamagnetic trapping system. There is also an interesting opportunity to realize a magnetic ratchet using a microwire with a circular domain structure. Thus, the magnetic manipulators based on systems of ferromagnetic microwires make it possible to organize fixation, redistribution and analysis of cell suspensions and magnetic nanoparticles. The biocompatibility of the glass shell of the microwires was demonstrated, hence, the possibility of their further using when working with living objects.