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Dynamic trajectory analysis of superparamagnetic beads driven by on-chip micromagnets
Xinghao Hu1, Roozbeh Abedini-Nassab2, Byeonghwa Lim1
1Department of Emerging Materials Science, DGIST , Daegu 711-873, South Korea.
Journal of Applied Physics
|December 10, 2015
Summary
We studied superparamagnetic beads near magnetic disks under rotating fields. Three distinct motion regimes were found: phase-locked, phase-slipping, and phase-insulated, revealing universal dynamics in non-uniform oscillators.
Area of Science:
- Physics
- Materials Science
- Non-linear Dynamics
Background:
- Superparamagnetic beads are utilized in various micro-devices.
- Understanding their motion dynamics is crucial for device optimization.
Purpose of the Study:
- To investigate the non-linear dynamics of superparamagnetic beads near patterned magnetic disks.
- To identify and characterize different dynamical regimes of bead motion.
Main Methods:
- Experiments using superparamagnetic beads (spherical and Janus) and patterned magnetic disks.
- Application of an in-plane rotating magnetic field.
- Automated particle position tracking and numerical simulations.
Main Results:
- Observed three distinct dynamical regimes: phase-locked, phase-slipping, and phase-insulated motion.
- Confirmed beads slide rather than roll using Janus particles.
- Experimental results for phase-locked and phase-slipping regimes align with simulations.
- Identified local magnetization defects as a likely cause for the phase-insulated state.
Conclusions:
- The three observed dynamical states are universal properties of bead motion in non-uniform magnetic oscillators.
- Further investigation is needed to fully predict the phase-insulated regime onset.
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