Curved Micro-Channels with Varying Cross-Sections for Particle Focusing and Mixing

Technology #15591

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Inventors
Professor Jongyoon Han
Research Laboratory of Electronics, EECS, MIT
External Link (www.rle.mit.edu)
Managed By
Michelle Hunt
MIT Technology Licensing Officer
Patent Protection

Microfluidic Device and Uses Thereof

US Patent Pending US 2015-0238963

Applications

  • Particle and cell separation by size
  • Water filtration

Problem Addressed

This device sorts and separates particles and cells by size using curved micro-channels.

Technology

The current device consists of microfluidic channels for applications in water filtration and purification at ultra-high throughputs. In micro-fluidic devices, particles flowing in curvilinear channels are influenced by both inertial migration and secondary Dean flows. The combination of Dean flow and inertial lift results in focusing and positioning of particles at distinct positions for concentration and separation applications. Apart from rectangular cross-section curved micro-channels that generate two symmetric Dean flow, the current technology introduces a set of curved micro-channels with non-rectangular cross-section that can alter the shapes and positions of the dean vortices to generate new focusing positions for particles. As an example, curved micro-channels with a deeper inner side (along the curvature center) and a shallow outer side generate two strong Dean vortex cores near the inner wall trapping all particles irrespective of size within the vortex. Such a channel finds vast applications in particle and cell concentration applications. On the other hand, if the curved micro-channel has a shallow inner side and a deeper outer side, the vortex centers will be skewed near the outer wall at the outer side and this will entrap particles and cells within the vortex. However, larger particles with dominant inertial force will still be focused near the inner channel walls, typical of rectangular cross-section channels. Thus, by designing appropriate channel parameters, small particles/cells will be trapped in the vortex at the outside, while relatively large particles will focus along inner microchannel wall. The threshold diameter determining whether a particle/cell is trapped within the Dean vortex or focused towards the inner channel wall is highly dependent on the flow rate. This enables such a device to achieve very good separation resolution between mixtures having a wide range of particle sizes. Since there are only two outlets for collection, the throughput is also much higher than standard rectangular channels

Advantages

  • High throughput
  • High separation resolution
  • Allows for very high starting cell and protein concentrations because clogging is prevented with new technology