Abstract: Analytical cartridges, systems and methods of processing a sample for analysis using capillary flows. Vertical gradient sample filtration provides filtrate to an incubation chamber for a time controlled by a flow modulator at the outlet of the incubation chamber. The flow modulator can include a serpentine capillary flow path without side walls. Incubated filtrate can flow from the incubation chamber to a detection channel after a predetermined time. The detection chamber can include one or more analytical regions in a porous substrate for detection of two or more analytes on the same cartridge from the same sample.

Abstract: This invention relates to a micromachined microfluidics diagnostic device that comprises one or multiple assaying channels each of which is comprised a sample port, a first valve, a reaction chamber, a second valve, a fluid ejector array, a third valve, a buffer chamber, a capture zone and a waste chamber. Each of these device components are interconnected through microfluidic channels. This invention further relates to the method of operating a micromachined microfluidic diagnostic device. The flow of fluid in the microchannels is regulated through micromachined valves. The reaction of sample analytes with fluorescent tags and detection antibodies in the reaction chamber are enhanced by the micromachined active mixer. By ejecting reaction mixture onto the capture zone through micromachined fluid ejector array, the fluorescent tagged analytes bind with capturing antiodies on capture zone. The fluid ejector array further ejects buffer fluid to wash away unbound fluorescent tags.

Abstract: This invention provides rotors and methods of precisely metering a sample fluid and mixing the sample with a reagent. The rotors have a metering tube of defined volume that fills until sample flow is stopped by surface tension of a meniscus at a capillarity port, while excess sample is stripped from the metering tube inlet by centripetal force of the spinning rotor. By spinning the rotor at a higher speed, a reagent can be forced from a reagent chamber to contact the meniscus, breaking the surface tension and allowing the metered sample to mix with the reagent.

Abstract: This invention relates to a systems and methods of controlling the flow of a fluid in a capillary or microfluidic channel. A first pair of electrodes can influence the wetting of a fluid front at a relatively hydrophobic surface in the channel. A second pair of electrodes can electrolytically generate a bubble that can stop fluid flow when it contacts the hydrophobic surface. Flow of a fluid in a channel can be stopped on contact with the hydrophobic surface and restarted when an electrostatic field reduces the contact angle of the fluid at the hydrophobic surface. The electrostatic field can be removed and the fluid stopped again when an electrolytically generated bubble contacts the hydrophobic surface to reestablish the blocking contact angle of the fluid, gas and surface.