A new method for continuous sorting of cells/particles using lattice-shaped dual-depth microchannels

In the last decade, various types of microfluidic cell/particle sorting devices have been developed, but most of these devices have limitations in terms of the relatively low throughput. In this paper, we describe a new scheme for continuous particle sorting, using high-density, lattice-shaped, and dual-depth microchannel networks. The lattice pattern composed of perpendicularly crossing deeper “main channels” and shallower “separation channels”, and the main channels are slanted against the overall flow direction. When particle suspension is continuously introduced, smaller particles reach the ceiling of the main channel, whereas larger particles do not. Consequently, larger particles enter the separation channels more frequently, resulting in the continuous particle separation. In the experiment, we successfully sorted microparticles based on size. In addition, the effects of the microchannel geometries and the vertical position of particles on the sorting efficiency were investigated. As application to biological samples, we demonstrated cell sorting using cultured mammalian cells. The presented mechanism of size-based particle sorting would be applicable to various research and industrial fields.