Research

When materials are exposed to an external magnetic field, the electrons' spins rearrange and generate magnetic dipole moments, which in turn affect the material's response to a magnetic field gradient. This leads to various magnetic properties, such as diamagnetism, paramagnetism, and ferromagnetism, determining the material's attraction or repulsion to the magnetic field.

For example, the bonds between hemoglobin and oxygen causes red blood cell to be repelled by magnetic field, inducing negative magnetic velocity. On the other hand, in deoxygenated red blood cells, the unpaired electrons can rearrange their spin following to the magnetic force, resulting positive magnetic velocity.

Since its high senstivity, selectivity, and efficiency, the magnetic separation is highlighted for cell separation, detection and analysis.

Based on the magnetic property of cell, we can perform cell separation and detection. The primary forces acting on the cells are magnetic force and gravity force, with additional reaction forces such as drag force and buoyancy force. In the presence of fluid flow within the channel, the inertia term associated with the flow is also taken into account. 

Through the utilization of these physical properties, we are able to measure cell properties and enhance the efficiency of cell separation.

Our current focus areas are sickle blood cell, cancer cells, and glioblastoma.

CTV is an innovative device that integrates a microscope camera with a microfluidic channel, creating a precisely controlled magnetic energy gradient. This setup allows for the precise tracking of cell and particle movements influenced by magnetic and gravitational fields.

Through a comparative analysis of settling velocity and magnetically induced velocity, we are able to investigate the properties of hemoglobin specifically associated with iron or magnetism.

By strategically positioning Quadrupolar orientation magnets, we establish a specific magnetic field gradient within the device, facilitating continuous separation. The implementation of a continuous flow system further enables uninterrupted particle sorting.

By incorporating additional measurement devices into the outlets, real-time monitoring becomes feasible, paving the way for limitless future applications.

MNPs are cutting-edge materials that have recently gained significant attention in various fields, including chemical and biomedical engineering applications, due to their exceptional properties. 

However, owing to the particles' nanometer-scale sizes, separating MNPs under the influence of a magnetic field is challenging, because Brownian motion impedes the separation of the desired particles from the surrounding medium.

We achieved successful separation of small SPIONs (5-30nm) by utilizing high magnetic fields and gradients. We also conducted in-situ Small Angle X-ray Scattering (SAXS) at Argonne National Laboratory to investigate the separation behavior for ferrofluid solution.

By utilizing COMSOL Multiphysics, a finite element analysis software designed for modeling and simulating physics-based phenomena, the magnetic fields and fluid flow velocities generated by different structures can be analyzed. These analyses serve as the basis for predicting particle movements.

The obtained simulation results play a crucial role in the development and scale up of highly efficient magnetic separators for cell separation.