Patent ID: 9052262
Filing Date: 2015-06-09
Classification: G01N

Abstract:
1. A method of controlling the flow of particles in or through an aperture between two reservoirs, the method comprising suspending the particles in a fluid within the aperture, applying a potential difference across the aperture so as to tend to electrophoretically transport the particles between a region of higher potential and a region of lower potential in the fluid to produce an output current, applying a pressure differential across the aperture so as to tend to transfer the fluid with the particles therein through the aperture from a high-pressure reservoir to a low-pressure reservoir, monitoring the particles before and/or during and/or after passage through the aperture by measuring the output current, and adjusting the potential difference and/or the pressure differential across the aperture in order to achieve control over the translation and in order to achieve control over the measurement of the particles within the aperture, wherein the concentration of the particles in the fluid is determined in dependence on the potential difference and/or the pressure differential applied across the aperture, and wherein the concentration of the particles in the fluid is determined by monitoring (i) the quantity of particles that pass through the aperture under different pressure conditions, and (ii) the quantity of particles in a fluid of known particle concentration that pass through the aperture under different pressure conditions.