Study of magnetic dipole in ferrofluid drop

Jyun Chen Shih^1*, Jin-Lin Wu¹, Hong-Yu Chu¹

¹Department of Physics, National Chung Cheng University, Chia-Yi, Taiwan

* Presenter:Jyun Chen Shih, email:a3525361@gmail.com

Ferrofluid is a kind of liquid that can be controlled by the magnetic field which is because of the colloidal particles Fe₃O₄ suspended in the carrier fluid. The dynamics of ferrofluid drop at time-independent magnetic field is discussed. The oil-based ferrofluid drop is attracted by the magnet in glycerin which is immiscible with ferrofluid. By using the balance equation of viscosity and the equivalent force acting on magnetic dipole, we show the measurement of the magnetic field along the trajectory of drop. The shape of the ferrofluid drop is shown to be a function of equivalent magnetic dipole length. We further test the different strengths of magnetic field and even tracing several drops to measure the strength of magnetic field in two dimensions.

Keywords: Ferrofluid, Magnetic dipole, Magnetic field measurement