Abstract: Magnetically actuated fluid handling devices using magnetic fluid to move one or more fluids (gases or liquids or both) through microsized flow channels are provided. Fluid handling devices include micropumps and microvalves. Magnetically actuated slugs of magnetic fluid are moved within microchannels of a microfluidic device to facilitate valving and/or pumping of fluids and no separate pump is required. The magnets used to control fluid movement can be either individual magnets moved along the flow channels or one or more arrays of magnets whose elements can be individually controlled to hold or move a magnetic slug. Fluid handling devices include those having an array of electromagnets positioned along a flow channel which are turned on and off in a predetermined pattern to move magnetic fluid slugs in desired paths in the flow channel. The fluid handling devices of the present invention can handle gases and liquids simultaneously and thus can be made to be self-priming.

Abstract: Magnetically actuated fluid handling devices using magnetic fluid to move one or more fluids (gases or liquids or both) through microsized flow channels are provided. Fluid handling devices include micropumps and microvalves. Magnetically actuated slugs of magnetic fluid are moved within microchannels of a microfluidic device to facilitate valving and/or pumping of fluids and no separate pump is required. The magnets used to control fluid movement can be either individual magnets moved along the flow channels or one or more arrays of magnets whose elements can be individually controlled to hold or move a magnetic slug. Fluid handling devices include those having an array of electromagnets positioned along a flow channel which are turned on and off in a predetermined pattern to move magnetic fluid slugs in desired paths in the flow channel. The fluid handling devices of the present invention can handle gases and liquids simultaneously and thus can be made to be self-priming.

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: This invention provides a method and apparatus for detecting the presence of analyte particles in a sample fluid also comprising larger particles, particularly blood. It exploits diffusion to provide simultaneous filtering of the larger particles and reaction of the analyte particles. A sample stream and a reagent stream join on the upstream end of a laminar flow reaction channel and flow in adjacent laminar streams. The reagents can be in solution or immobilized on a bead. The analyte particles diffuse from the sample stream into the reagent stream, leaving behind the larger particles in the residual sample stream. In the reagent stream the analyte particles react with reagent particles and form product particles, thereby creating a product stream. At the downstream end of the reaction channel, the residual sample stream and the product stream are divided. The product particles are then detected, preferably optically, in the product stream.

Abstract: This invention provides a method and apparatus for detecting the presence of analyte particles in a sample fluid also comprising larger particles, particularly blood. It exploits diffusion to provide simultaneous filtering of the larger particles and reaction of the analyte particles. A sample stream and a reagent stream join on the upstream end of a laminar flow reaction channel and flow in adjacent laminar streams. The reagents can be in solution or immobilized on a bead. The analyte particles diffuse from the sample stream into the reagent stream, leaving behind the larger particles in the residual sample stream. In the reagent stream the analyte particles react with reagent particles and form product particles, thereby creating a product stream. At the downstream end of the reaction channel, the residual sample stream and the product stream are divided. The product particles are then detected, preferably optically, in the product stream.

Abstract: Magnetically actuated fluid handling devices using magnetic fluid to move one or more fluids (gases or liquids or both) through microsized flow channels are provided. Fluid handling devices include micropumps and microvalves. Magnetically actuated slugs of magnetic fluid are moved within microchannels of a microfluidic device to facilitate valving and/or pumping of fluids and no separate pump is required. The magnets used to control fluid movement can be either individual magnets moved along the flow channels or one or more arrays of magnets whose elements can be individually controlled to hold or move a magnetic slug. Fluid handling devices include those having an array of electromagnets positioned along a flow channel which are turned on and off in a predetermined pattern to move magnetic fluid slugs in desired path in the flow channel. The fluid handling devices of the present invention can handle gases and liquids simultaneously and thus can be made to be self-priming.

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 devices.

Abstract: This invention provides a method and apparatus for detecting the presence of analyte particles in a sample fluid also comprising larger particles, particularly blood. It exploits diffusion to provide simultaneous filtering of the larger particles and reaction of the analyte particles. A sample stream and a reagent stream join on the upstream end of a laminar flow reaction channel and flow in adjacent laminar streams. The reagents can be in solution or immobilized on a bead. The analyte particles diffuse from the sample stream into the reagent stream, leaving behind the larger particles in the residual sample stream. In the reagent stream the analyte particles react with reagent particles and form product particles, thereby creating a product stream. At the downstream end of the reaction channel, the residual sample stream and the product stream are divided. The product particles are then detected, preferably optically, in the product stream.

Abstract: Therapeutic complexes comprising plural therapeutic compounds self assembled into high axial ratio microstructures are described. The therapeutic complexes satisfy the formula HARM-Th, wherein HARM is a high axial ratio forming material and Th is a therapeutic coupled to or associated with the HARM. The therapeutic complexes also can satisfy the formula HARM-S-Th, wherein S is a spacer. Release of the therapeutic by the complex generally follows either 0-order kinetics or psuedo-first order kinetics. A method for delivering therapeutics to oransims, particularly humans, also is described. The method comprises administering an effective amount of (1) a ligand, such as a therapeutic, self-assembled into a HAR microstructure, or (2) a ligand, such as a therapeutic, coupled to or associated with a material capable of thereafter self-assembling into a high axial ratio microstructure, to the mammal.

Abstract: The present invention provides a sheath flow module made from a first plate of material having formed therein a laminar fluid flow channel; at least two inlets, each inlet joining the laminar flow channel at a junction, the first inlet junction being wider than the second inlet junction, and an outlet from the flow channel. A second plate, e.g. a transparent cover plate, seals the module and allows for optical measurements. A first inlet allows for introduction of a first fluid into the flow channel. The first fluid is the sheath fluid. A second inlet allows for introduction of a second fluid into the sheath fluid while it is flowing through the flow channel. The second fluid is the center fluid. Because the second inlet junction is narrower than the first inlet junction, the center fluid becomes surrounded on both sides by the sheath fluid. After all fluids have been introduced and sheath flow has been achieved, the depth of the flow channel can be decreased, leading to vertical hydrodynamic focusing.

Abstract: The present invention provides microband electrode array sensors for detecting the presence and measuring the concentration of analytes in a sample. The microband electrodes of the invention have both a width and a thickness of microscopic dimensions. Preferably the width and thickness of the microband electrodes are less than the diffusion length of the analyte(s) of interest. In general, both the thickness and width of the electrodes are less than about 25 micrometers. The electrodes are separated by a gap insulating material that is large enough that the diffusion layers of the electrodes do not overlap such that there is no interference and the currents at the electrodes are additive. Microband electrode arrays of this invention exhibit true steady-state amperometric behavior.

Abstract: A method for patterning a material onto a substrate including the steps of: providing a micro-mold having a plurality of non-communicating independent channels and having a plurality of reservoirs for receiving a micro-molding fluid each of which reservoirs communicates with a channel, the micro-mold including an elastomeric master having a surface with a plurality of recesses therein and a substrate; introducing a micro-molding fluid into the micro-mold reservoirs filling said communicating channels; and solidifying the fluid in the micro-mold and removing the elastomeric master thereby generating a pattern of material on the substrate. The micro-mold is formed by contacting the surface of the elastomeric master with the substrate such that the recesses in the surface form the plurality of reservoirs and channels.

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 devices.

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: This invention provides an extraction device and a method for extracting desired particles from a sample stream containing the desired particles. The device has a sample stream inlet, an extraction stream inlet, and an extraction channel in fluid communication with the sample stream inlet and the extraction stream inlet. The extraction channel is for receiving a sample stream from the sample stream inlet in adjacent laminar flow with an extraction stream from the extraction stream inlet. A sequestering material within the extraction channel captures desired particles in the extraction stream. A by-product stream outlet in fluid communication with the extraction channel receives a by-product stream comprising at least a portion of the sample stream form which desired particles have been extracted. A product outlet in fluid communication with the extraction channel receives a product which has the sequestering material and at least a portion of the desired particles.

Abstract: This invention provides a microfabricated extraction system and methods for extracting desired particles from a sample stream containing desired and undesired particles. The sample stream is placed in laminar flow contact with an extraction stream under conditions in which inertial effects are negligible. The contact between the two streams is maintained for a sufficient period of time to allow differential transport of the desired particles from the sample stream into the extraction stream. In a preferred embodiment the differential transport mechanism is diffusion. The extraction system of this invention coupled to a microfabricated diffusion-based mixing device and/or sensing device allows picoliter quantities of fluid to be processed or analyzed on devices no larger than silicon wafers.

Abstract: Therapeutic agents comprising plural therapeutic compounds self assembled into high axial ratio microstructures are described. The threapeutic compounds satisfy the formula HARFM-Th, wherein HARFM is a high axial ratio forming material and Th is a therapeutic associated with the HARFM. The therapeutic agent also can satisfy the formula HARFM-S-Th, wherein S is a spacer. Release of the therapeutic by the agent generally follows either 0-order kinetics or psuedofirst order kinetics. A method for delivering drugs to animals or persons also is described. The method comprises administering an effective amount of a therapeutic self-assembled into an HAR microstructure to the animal or person.

Abstract: The present invention provides a flow cytometer made of two components: a flow cytometer optical head and a disposable flow module. The flow module utilizes a V-groove flow channel micromachined in a silicon wafer. The optical head comprises a laser to provide an illuminating beam and small and large angle photodetectors. Anisotropically etched facets of the V-groove reflect the illuminating beam. Small angle scattered light is also reflected by the V-groove wall and is collected by the small angle photodetector. Large angle scattered light and fluorescent light can exit the channel without reflection and are collected by the large angle photodetector. In addition, fluorescent light can be back-reflected by the V-groove, which enhances the collection efficiency.

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.

Abstract: A swimming pool water analyzer has a housing providing a coulometric titration chamber, a chlorine concentration measuring chamber, a chamber for measuring pH, and conduits connecting the several chambers, the reservoir and a discharge outlet. One or more pumps move fluid through the conduits and chambers to the discharge outlet. Electrodes in each of the chambers are connected to electrical circuitry, and a power supply is provided. A microprocessor receives and analyzes signals indicative of the activity at the electrodes and provides outputs representing values for the chemistry of the sample determined as a result of such analysis of the signals.