Particle separation and concentration system

摘要

This invention is based on size and mass separation of suspended particles, including biological matter, which are made to flow in a spiral channel. On the spiral sections, the inward directed transverse pressure field from fluid shear competes with the outward directed centrifugal force to allow for separation of particles. At high velocity, centrifugal force dominates and particles move outward. At low velocities, transverse pressure dominates and the particles move inward. The magnitudes of the two opposing forces depend on flow velocity, particle size, radius of curvature of the spiral section, channel dimensions, and viscosity of the fluid. At the end of the spiral channel, a parallel array of outlets collects separated particles. For any particle size, the required channel dimension is determined by estimating the transit time to reach the side-wall. This time is a function of flow velocity, channel width, viscosity, and radius of curvature. Larger particles may reach the channel wall earlier than the smaller particles which need more time to reach the side wall. Thus a spiral channel may be envisioned by placing multiple outlets along the channel. This technique is inherently scalable over a large size range from sub-millimeter down to 1 μm.

主权项

1. A device for handling particles within a fluid, the device comprising:
an inlet operative to receive fluid containing particles; a channel operative to allow a flow of the fluid, the channel being in a spiral configuration to separate particles based on geometric parameters and by allowing a continuous flow of the fluid at a flow velocity to move particles through the channel and selectively migrate particles across the channel based on centrifugal forces and pressure driven forces to separate particles to outside or inside walls of the channel; a means for collecting the particles within the fluid; and, at least one outlet for the fluid.