Patent ID: 6637257
Filing Date: 2003-10-28
Classification: G01N,Y10T

Abstract:
A micromachined filtering device comprising:a substrate having a first surface, an oppositely-disposed second surface, and a thickness defined by and between the first and second surfaces; a plurality of vias through the thickness of the substrate, the vias being spaced apart and having approximately equal diameters that permit passage through the substrate of material having a diametrical dimension less than the diameters of the vias and to prevent passage through the substrate of material having a diametrical dimension greater than the diameters of the vias; and first and second electrodes on the first surface of the substrate, the first and second electrodes being located on the first surface so that material that is too large to pass through the vias and therefore collects at the first surface of the substrate will electrically connect the first and second electrodes to produce an output signal in proportion to the amount of material collected at the first surface.