3d microfluidic device and method of separating particles by size from a suspension

A method of separating particles by size from a suspension sample, comprising:

• introducing the suspension sample into the inlet of a flow channel;
• and
• flowing the sample suspension through the flow channel from the inlet serially through (a) an inlet section, extending along a first tangent, (b) an intermediate spiral section, (c) an outlet section, extending along a second tangent, and (d) a 3D outlet system including a first center outlet, a second center outlet, an upper outlet and a lower outlet wherein particles of a first size pass through the upper and lower outlets, particles of a second size pass through the first center outlet and particles of a third size pass through the second center outlet.

A microfluidic device, comprising:

• a flow channel including (a) an inlet, (b) an inlet section, extending along a first tangent, (c) an intermediate spiral section, (d) an outlet section, extending along a second tangent, and (e) an 3D outlet system including an upper outlet, a lower outlet, a center left outlet and a center right outlet whereby particles in a suspension passing through the flow channel are separated for recovery of different size particles through the (a) upper and lower outlets, (b) the center left outlet and (c) the center right outlet.