Patent ID: 7931792
Filing Date: 2011-04-26
Classification: B03C

Abstract:
1. A system for concentrating and analyzing a plurality of particles collected from a fluid stream, comprising: a dielectric base portion comprising an open flow channel formed therein, the open flow channel comprising connected channel regions, wherein each of the channel regions comprise a predetermined depth, a uniform rectangular cross section, a longitudinal axis, and first and second side walls each aligned substantially parallel to the longitudinal axis, wherein at least first and second channel regions intersect at a first intersection plane passing through an intersection between the respective first side walls and the respective second side walls of the at least first and second channel regions, and wherein a normal to the first intersection plane is oriented at a first angle, θ 11 , with respect to the longitudinal axis of the first channel region, and oriented at a second angle, θ 12 , with respect to the longitudinal axis of the second channel region; the first channel region further comprising a first predetermined channel depth, d the second channel region further comprising a second predetermined channel depth, d wherein σ 1 and σ 2 are first and second predetermined design permeabilities, respectively proportional to d 1 and d 2 , and related by a compatibility condition comprising wherein σ 1 >σ 2 , and wherein a fluid flowing from the first channel region into the second channel region and comprising a flux that is substantially uniform in the first channel region, remains substantially uniform in the second channel region; a first electrode disposed at an inlet of the open flow channel and second electrode disposed at an outlet of the open flow channel, the electrodes attached to an adjustable source of electrical energy; wherein the electrodes and the adjustable source of electrical energy are configured to provide a steady electrical field across each channel region rectangular cross section, wherein the first electrode is held at a potential more negative then the second electrode, and wherein the electric field transports a conduction fluid through the open flow channel, and wherein the electric field is further adjustable to impart a dielectrophoretic force to a particle suspended in the conduction fluid sufficient to inhibit the particle from passing the first intersection plane; a collection channel opening into the flow channel and disposed between the inlet and the outlet, wherein the collection channel opens into the first channel region at a point distal to the inlet and adjacent the intersection of the first and second channel region respective second side walls; a dielectric cover portion disposed over the base portion; and a particle detection means, comprising: