On-chip manipulation of magnetic nanoparticles through domain walls conduits

TL;DR

This paper proposes a method for precise on-chip manipulation of individual magnetic nanoparticles using controlled magnetic domain walls in nanoscale structures, enabling advanced applications in biosensing and molecular manipulation.

Contribution

It introduces a novel technique to control magnetic domain walls for nanometer-scale manipulation of single magnetic nanoparticles on a chip.

Findings

High control over domain wall nucleation and movement demonstrated

Method enables capture, transport, and release of magnetic nanoparticles

Potential applications in single molecule and cell manipulation

Abstract

The manipulation of geometrically constrained magnetic domain walls (DWs) in nanoscale magnetic strips has attracted much interest recently, with proposals for prospective memory and logic devices. Here we propose to use the high controllability of the motion of geometrically constrained DWs for the manipulation of individual nanoparticles on a chip with an active control of position at the nanometer scale. The proposed method exploits the fact that magnetic nanoparticles in solution can be captured by a DW, whose position can be manipulated with nanometric accuracy in a specifically designed magnetic nanowire structure. We show that the high control over DW nucleation, displacement, and annihilation processes in such structures can be used to capture, transport and release magnetic nanoparticles. As magnetic particles with functionalized surfaces are commonly used as molecule carriers or labels, the accurate control over the handling of the single magnetic nanoparticle is crucial for several applications including single molecule manipulation, separation, cells manipulation and biomagnetic sensing.