On-chip nano-manipulation of magnetic particles via domain walls conduits

TL;DR

This paper introduces a novel on-chip method for manipulating magnetic nanoparticles using controlled magnetic domain walls in nanoscale structures, enabling precise transport and release for applications in molecular and biomagnetic sensing.

Contribution

It presents a new technique leveraging domain wall control for nanometer-scale manipulation of magnetic particles, advancing on-chip nano-transport and molecular handling capabilities.

Findings

High control over domain wall nucleation, displacement, and annihilation.

Successful capture, transport, and release of magnetic nanoparticles.

Potential for integration into lab-on-chip and molecular manipulation devices.

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 labels in several applications - including single molecule manipulation, separation, cells manipulation and biomagnetic sensing, the accurate control over the handling of the single magnetic nanoparticles becomes crucial as it may reflect the handling of the single molecules. The approach described here opens the path to the implementation and design of nano-transport lines, with application to single molecule study and lab-on-chip devices. In perspective, the easy integration on chip with sensors of domain walls and particles will allow for the realization of programmable circuits for molecular manipulation with continuous control of the desired process.