Self-Assembled Permanent Micro-Magnets in a Polymer-Based Microfluidic Device for Magnetic Cell Sorting.
Lucie Descamps1, Marie-Charlotte Audry1, Jordyn Howard1
1CNRS, INSA Lyon, Ecole Centrale de Lyon, CPE Lyon, INL, UMR5270, University Lyon, Université Claude Bernard Lyon 1, 69622 Villeurbanne, France.
Cells
|August 7, 2021
Summary
Researchers developed an inexpensive method to create micro-scale magnets using self-organized magnetic particles in PDMS. These micro-magnets enable efficient magnetophoresis for applications like cell sorting and bead manipulation in microfluidic devices.
Area of Science:
- Microfluidics
- Materials Science
- Biotechnology
Background:
- Magnetophoresis offers precise micro-scale object manipulation but faces fabrication challenges for micro-magnets.
- Existing methods for integrating micro-magnets are often complex and costly.
Purpose of the Study:
- To develop an inexpensive and straightforward fabrication process for micrometer-scale permanent magnets.
- To integrate these micro-magnets into microfluidic devices for various applications.
- To demonstrate the efficacy of these micro-magnets in trapping and sorting applications.
Main Methods:
- Fabrication of micro-magnets via self-organization of NdFeB particles in a polydimethylsiloxane (PDMS) matrix.
- Characterization of micro-magnet structure using X-ray tomography.
- Magnetic performance estimation via COMSOL simulations and colloidal probe atomic force microscopy (AFM).
- Integration into microfluidic devices for magnetophoretic trapping and cell sorting.
Main Results:
- Achieved chain-like organization of NdFeB particles, forming 4 µm diameter magnetic microstructures.
- Measured magnetic forces up to several nanonewtons on superparamagnetic beads.
- Demonstrated 100% trapping efficiency for magnetic beads at 0.5 mL/h and 75% at 1 mL/h.
- Successfully performed white blood cell depletion using the integrated micro-magnets.
Conclusions:
- The self-assembly method provides an inexpensive and scalable route to micro-scale permanent magnets.
- The developed micro-magnets are effective for precise manipulation and sorting of micro-scale objects in microfluidic systems.
- This technology has significant potential for applications in cell sorting and other biotechnological processes.
