Patent ID: 7371310

Claim:
An apparatus for analyzing or processing a sample, comprising: a.) a substrate fabricated to include a microchannel system disposed therein, said microchannel system comprising at least first and second process channels and at least a waste channel and at least a supply channel, wherein each of said process, said waste and said supply channels has a first end and a second end opposite said first end, wherein each of said process, said waste and said supply channels lie in a common plane, wherein said first and second process channels are substantially co-linear and disposed along a primary axis, and wherein said waste said supply channels lie on opposite sides of said primary axis; b.) at least one junction formed at an intersection of said first ends of said process, said waste and said supply channels, wherein said at least one junction comprises cusp-like extensions at said first ends of said process channels, wherein said cusp-like extensions protrude into said junction; c.) reservoir means for introducing a sample material into said microchannel system, said sample material comprising one or more different species; d.) one or more power supplies; e.) electrode means connecting each of said one or more power supplies with said second end of each of said at least first and second process, said waste, and said supply channels; f.) a transport medium disposed within each of said process, said waste and said supply channels and within said junction; g.) means for inserting a band of said sample material into a region near said first end of said first process channel; and h.) means for controlling each of said one or more power supplies to establish the same or different respective electric fields along each of said at least said process, said waste and said supply channels, wherein each of said electric fields induce transport of said sample band at least partially across said junction at least once, said transport causing said sample band to expand as a continuous shell, wherein said sample band is stretched and thinned while traversing said junction providing thereby a sample band having a thickness of less than two channel widths.