Abstract: A device for promoting protein crystal growth (PCG) using microfluidic channels. A protein sample and a solvent solution are combined within a microfluidic channel having laminar flow characteristics which forms diffusion zones, providing for a well defined crystallization. Protein crystals can then be harvested from the device. The device is particularly suited for microgravity conditions.

Abstract: Multifluidic devices and methods are provided for enhancing detection of a diffusion pattern formed by particles diffusing between at least tow fluid streams I parallel laminar flow such that an interface is formed between them by increasing the dimension of the streams in the diffusion direct. This may be accomplished by flowing the streams through a transforming turn, or by flowing the streams through a channel having diverging walls. Devices and methods are also provided for enhancing diffusion between two streams comprising changing the interface between said streams from a narrow interface to a broad interface.

Abstract: A device and method for performing a microfluidic process. A device includes a plurality of reservoirs, each connected a microfluidic channel. The microfluidic channel is arranged to use gravitational force to combine at least two fluids, from respective reservoirs of the plurality of reservoirs, when the respective reservoirs are positioned above an end of the microfluidic channel. The microfluidic channel is further arranged such that by rotation of the microfluidic channel, the direction of flow of the combined fluids is reversed to prolong the interaction between the fluids.

Abstract: A method and apparatus for performing a microfluidic process. An apparatus includes an arrangement comprising a first tank and a second tank having an inlet connected to an outlet of the first tank. The arrangement also includes a third tank adjacent to the first tank and a fourth tank, adjacent to the second tank, and having an inlet connected to an outlet of the third tank. The arrangement further includes a microfluidic channel having a first inlet connected to an outlet of the second tank, a second inlet connected to an outlet of the fourth tank, and a first outlet connected to an inlet of the first tank. In operation, the first and third tank are filled with fluids in a first, initial position. The arrangement is rotated to transfer the fluids to respective second and fourth tanks in a second position, and then rotated back to the first position where the fluids enter the microfluidic channel. The steps can be repeated until the desired process is accomplished.

Abstract: The present invention provides a microfabricated sensor and a method capable of rapid simultaneous measurement of multiple analytes in a fluid sample. The sensor is inexpensive, disposable and portable, and requires only microliters of sample, a particular advantage with precious fluids such as blood. The sensor utilizes diffusion between layered laminar streams rather than side by side streams. This allows multiple side by side channels for simultaneous detection of multiple analytes. In the sensor, a sample stream and a carrier stream flow in layers, one on top of the other, and one or more reagents are introduced to the bottom of the carrier stream through either a fluid or a solid reagent inlet. The reagent contains reagent particles which, in the presence of the analyte, have a detectable change in a property. The analyte diffuses into the carrier stream where it interacts with reagent particles and is detected by optical, electrochemical or other means.

Abstract: A capillary for introduction of whole blood into an analysis device. The capillary has a variable volume along its length, which allows the liquid sample to be drawn into the interior of the cartridge, away from the inlet, reducing the risk of contamination of the sample from the outside.

Abstract: A passive valve for use within microfluidic structures. Surface tension forces developed within microscale channels are used to control flow within the channels. Flow can be halted within a channel until fluid force reaches a predetermined pressure to allow the channel to open.

Abstract: A method and apparatus are disclosed for controlling a flow rate of a fluid sample having an unknown or variable viscosity. The fluid sample is provided as a first fluid flow to a microfluidic channel. A second fluid is provided to the channel as a sheath around the first fluid. In one embodiment, the second fluid is injected between the first fluid flow and an internal surface of the channel. In another embodiment, the second fluid completely circumscribes the first fluid as a parallel or sheath flow. The second fluid has a known viscosity selected for achieving a flow rate. The first fluid flows at the same rate as the achieved flow rate of the second fluid.

Abstract: A microfluidic device and method for improved diffusion between at least two parallel-flowing fluids. A structure for a microfluidic device includes a first inlet channel, a second inlet channel, and at least one outlet channel connected to the first and second inlet channels. A measure of the first inlet channel is smaller than a measure of the second inlet channel, directing a particular cross-sectional flow in the outlet channel that avoids a “butterfly effect” of adverse diffusion. In an outlet channel having at least two fluidic inlets, the chemical or physical properties of parallel-flowing fluids are controlled for diffusion, concentration, extraction or detection of a substance among the fluids.

Abstract: A device for analyzing sample solutions such as whole blood based on coagulation and agglutination which requires no external power source or moving parts to perform the analysis.

Abstract: A device for performing polymerase chain reaction (PCR) amplification and detection using microfluidic diffusion-based structures. Fluid containing DNA to be amplified is cycled repeatedly across hot and cold zones to enhance the multiplication process. The invention is used in conjunction with other devices to perform both single and multiple target detection.

Abstract: A device for promoting protein crystal growth (PCG) using microfluidic channels. A protein sample and a solvent solution are combined within a microfluidic channel having laminar flow characteristics which forms diffusion zones, providing for a well defined crystallization. Protein crystals can then be harvested from the device. The device is particularly suited for microgravity conditions.

Abstract: A reference sensor system is provided for detecting the presence and/or measuring the concentration of analyte particles in a sample stream. The system includes: a) a laminar flow channel; b) three or more inlet means in fluid connection with the laminar flow channel for respectively conducting into the laminar flow channel (1) an indicator stream which may include an indicator substance which indicates the presence of the analyte particles, (2) the sample stream, and (3) a reference stream, which can be a control stream and/or internal standard stream; and, c) wherein the laminar flow channel has a depth and/or width sufficiently small to allow laminar flow of said streams and a length sufficient to allow particles of the analyte to diffuse into the indicator stream to form a detection area. Branching channels may be provided as outlet means for conducting the streams out of the laminar flow channel.

Abstract: A method and apparatus including programmed computers are provided for determining the viscosity of a first stream in a laminar flow and a second stream in a laminar flow, the flow rates, the centerline of the flow channel, and the position of the interface between the streams with respect to the centerline, and for calculating viscosity ratio of the first stream to the second.

Abstract: A device and method for performing spectral measurements in flow cells with spatial resolution using a variable transmission optical filter having at least two areas with different optical properties. Light from a light source passes through the variable transmission filter to a flow cell containing a sample to be analyzed. The resultant light pattern is sensed by a detecting means, which analyzes the spectral properties of the sample within the flow cell.

Abstract: Methods and apparatuses including programmed computers are provided for determining the initial concentration of diffusible particles in a sample stream introduced into a system wherein the sample stream which contains the diffusible particles flows in adjacent laminar flow with an indicator stream containing an indicator substance capable of exhibiting an observable change at a known concentration of the diffusible particles.

Abstract: A channel-cell system is provided for detecting the presence and/or measuring the presence of analyte particles in a sample stream comprising: a) a laminar flow channel; b) two inlets in fluid connection with the laminar flow channel for respectively conducting into the laminar flow channel (1) an indicator stream which may comprise an indicator substance which indicates the presence of the analyte particles by a detectable change in property when contacted with the analyte particles, and (2) the sample stream; c) wherein the laminar flow channel has a depth sufficiently small to allow laminar flow of the streams and a length sufficient to allow particles of the analyte to diffuse into the indicator stream to the substantial exclusion of the larger particles in the sample stream to form a detection area; and d) an outlet for conducting the streams out of the laminar flow channel to form a single mixed stream.

Abstract: A reference T-sensor system is provided for detecting the presence and/or measuring the concentration of analyte particles in a sample stream. The system includes: a) a laminar flow channel; b) three or more inlet means in fluid connection with the laminar flow channel for respectively conducting into the laminar flow channel (1) an indicator stream which may include an indicator substance which indicates the presence of the analyte particles, (2) the sample stream, and (3) a reference stream, which can be a control stream and/or internal standard stream; c) wherein the laminar flow channel has a depth and/or width sufficiently small to allow laminar flow of the streams and a length sufficient to allow particles of the analyte to diffuse into the indicator stream to form a detection area; and d) outlet means for conducting the streams out of the laminar flow channel preferably to form a single mixed stream.

Abstract: The present invention provides a method and apparatus for rapid measurement of a fluid bulk analyte, requiring only microscale volumes. Several fluid bulk analytes can be measured simultaneously and, for biological samples, the cell content can also be measured simultaneously. The invention comprises reporter beads for chemical analysis of fluid bulk properties such as pH, oxygen saturation and ion content. Each reporter bead comprises a substrate bead having a plurality of at least one type of fluorescent reporter molecules immobilized thereon. The fluorescent properties of the reporter bead are sensitive to a corresponding analyte. Reporter beads are added to a fluid sample and the analyte concentration is determined by measuring fluorescence of individual beads, for example in a flow cytometer. Alternatively, reporter molecules which change absorbance as a function of analyte concentration can be employed.

Abstract: A channel-cell system is provided for detecting the presence and/or measuring the presence of analyte particles in a sample stream comprising: a) a laminar flow channel; b) two inlet means in fluid connection with said laminar flow channel for respectively conducting into said laminar flow channel (1) an indicator stream which may comprise an indicator substance which indicates the presence of said analyte particles by a detectable change in property when contacted with said analyte particles, and (2) said sample stream; c) wherein said laminar flow channel has a depth sufficiently small to allow laminar flow of said streams and a length sufficient to allow particles of said analyte to diffuse into said indicator stream to the substantial exclusion of said larger particles in said sample stream to form a detection area; and d) outlet means for conducting said streams out of said laminar flow channel to form a single mixed stream.