# Efficient Particle Capture and Release Method for DNA Library Preparation on Microfluidics

## TL;DR

This paper introduces a method to efficiently capture and release magnetic particles in microfluidic devices for DNA library preparation.

## Contribution

A novel microchamber design and synergistic flow-magnetic field approach for improved particle capture and release in microfluidics.

## Key findings

- Magnetic particle coverage in the microchamber increased from 17.29% to 63.59% with varying inlet flow velocity and magnet spacing.
- Magnetic particle capture rate decreased from 100% to 35.2% under the same conditions.
- Magnetic particles were fully released within 12 seconds with a 100% release rate.

## Abstract

To address the issues of agglomeration during magnetic particle capture and the incomplete release of these particles during reuse in microfluidic chips for library preparation, a microchamber was utilized to enhance the dispersion area for magnetic particle capture. Additionally, the release of magnetic particles was achieved through the synergistic action of flow field and magnetic field. The simulation results indicated that as the inlet flow velocity varied from 0.02 m/s to 0.16 m/s and the magnet spacing ranged from 1.2 mm to 1.8 mm, the coverage of magnetic particles in the microchamber increased from 17.29% to 63.59%. Meanwhile, the magnetic particle capture rate decreased from 100% to 35.2%. These processes were further validated through experimental methods. During the release process, the trajectory of magnetic particles under the synergistic effect of flow field and magnetic field aligned with expectations. The captured magnetic particles were released from the microchamber within 12 s, achieving a release rate of 100%.