Abstract: A microfluidic device for assessing properties of a fluid. The device utilizes a microtube capable of different vibration modes for promoting certain performance and/or structural aspects of the device. The microtube is supported by a base so as to be spaced apart from a substrate surface. The microtube has a peripheral portion surrounding the base, arms supporting the peripheral portion from the base, and a continuous internal microchannel having at least first and second microchannel portions. Each microchannel portion defines a separate flow route, and each flow route originates at the base, continues through a portion of the peripheral portion, and returns to the base. The first and second microchannel portions are fluidically connected to inlet and outlet ports, respectively, within the base. Vibration of the microtube is induced and sensed by driving and sensing elements. Fluid properties are determined from outputs of the sensing elements.

Abstract: A process for fabricating multiple microfluidic device chips. The process includes fabricating multiple micromachined tubes in a semiconductor device wafer. The tubes are fabricated so that each tube has an internal fluidic passage and an inlet and outlet thereto defined in a surface of the device wafer. The device wafer is then bonded to a glass wafer to form a device wafer stack, and so that through-holes in the glass wafer are individually fluidically coupled with the inlets and outlets of the tubes. The glass wafer is then bonded to a metallic wafer to form a package wafer stack, so that through-holes in the metallic wafer are individually fluidically coupled with the through-holes of the glass wafer. Multiple microfluidic device chips are then singulated from the package wafer stack. Each device chip has a continuous flow path for a fluid therethrough that is preferably free of organic materials.

Abstract: A process for producing a micromachined tube (microtube) suitable for microfluidic devices. The process entails isotropically etching a surface of a first substrate to define therein a channel having an arcuate cross-sectional profile, and forming a substrate structure by bonding the first substrate to a second substrate so that the second substrate overlies and encloses the channel to define a passage having a cross-sectional profile of which at least half is arcuate. The substrate structure can optionally then be thinned to define a microtube and walls thereof that surround the passage.

Abstract: A microfluidic device and method for assessing properties of a fluid. The device includes a base supported by a substrate and a tube extending from the base and spaced apart from the substrate surface. The tube has an internal passage, first and second portions adjacent the base and defining, respectively, an inlet and outlet of the passage, and a distal portion. A drive electrode is located on the substrate surface adjacent the distal portion of the tube. Sensing electrodes are located on the substrate surface adjacent the first and second portions of the tube, and are adapted for sensing deflections of the first and second portions when vibrated with the drive electrode and from which the fluid property is determined. A pair of electrodes is located on the substrate surface between the drive and sensing electrodes, and are operated to enhance the performance of the microfluidic device, such as by supplementing the drive or sensing electrodes.

Abstract: A microfluidic device a micromachined freestanding member adapted to sense one or more properties of a fluid flowing through the freestanding member. The freestanding member is supported by a substrate and spaced apart and separated from the substrate to enable the freestanding member to move relative to the substrate under the influence of a vibration-inducing element. Movement of the freestanding member relative to the substrate is then sensed by a sensing element. The freestanding member has an inlet, an outlet, an internal passage that fluidically couples the inlet and outlet, and a wall that defines and separates first and second passage portions of the internal passage that are arranged in fluidic series so that a fluid flowing through the internal passage flows through the first and second passage portions in opposite directions.

Abstract: A fluid sensing system and method for sensing properties of a flowing fluid. The system and method entail a microfluidic device having a micromachined tube supported above a substrate, a tube passage within a freestanding portion of the tube, an inlet and outlet in fluidic communication with the tube passage and an exterior of the microfluidic device, elements for vibrating the freestanding portion of the tube, and elements for sensing movement of the freestanding portion of the tube so as to measure the vibration frequency and/or deflection of the freestanding portion and produce therefrom at least one output corresponding to a property of a fluid flowing through the tube passage. The system and method further entail placing the microfluidic device in a flowing fluid so that a fraction of the fluid enters the tube passage, and processing the output of the device to compute a property of the fluid.

Abstract: A system for monitoring a charge-based physiological parameter within an internal organ of a living body, and a sensor adapted to be implanted in the living body and an organ therein. The sensor includes sensing elements adapted to sense the charge-based physiological parameter within the organ, and the sensing elements include at least first and second sensing elements that are electrically conductive, aligned, spaced apart and exposed at the exterior of the sensor. The sensor further includes a device for passing an alternating current from the first to the second sensing elements through an ionic solution contacting the sensing elements. The sensor also includes a device for generating a signal corresponding to the impedance of the ionic solution based on the alternating current.

Abstract: A microfluidic device and sensing method that utilize a resonating tube configured to have sufficient sensitivity to be capable of sensing the volume of a gas present as bubbles in a liquid or the flow rate and/or density of a gas or gas mixture flowing through the tube. The tube has a freestanding tube portion supported above a surface of a substrate so as to be capable of vibrating in a plane normal to the surface of the substrate. As a gas-containing fluid flows through an internal passage of the tube, a drive signal vibrates the freestanding tube portion at a resonant frequency thereof. Coriolis-induced deflections of the freestanding tube portion are sensed relative to the substrate to produce an output corresponding to the sensed deflections, and the drive signal and/or the output are assessed to determine the volume, density and/or flow rate of the gas of the gas-containing fluid.

Abstract: A sensing and analysis system, method, and network that make use of a very portable and compact sensor unit and a physically separate electronic unit that serves to power and control the sensor unit, process and optionally display the output of the sensor unit, and transmit the sensor output to other locations, such as over a network. The sensor unit includes a housing, a sensing element within the housing and responsive to an input, and electronic circuitry within the housing and in communication with the sensing element to produce an electrical output based on an output signal generated by the sensing element. A communication providing device delivers instructions generated by the electronic unit to the sensor unit and delivers the electrical output from the sensor unit to the electronic unit.

Abstract: A microfluidic device for assessing properties of a fluid. The device utilizes a microtube capable of different vibration modes for promoting certain performance and/or structural aspects of the device. The microtube is supported by a base so as to be spaced apart from a substrate surface. The microtube has a peripheral portion surrounding the base, arms supporting the peripheral portion from the base, and a continuous internal microchannel having at least first and second microchannel portions. Each microchannel portion defines a separate flow route, and each flow route originates at the base, continues through a portion of the peripheral portion, and returns to the base. The first and second microchannel portions are fluidically connected to inlet and outlet ports, respectively, within the base. Vibration of the microtube is induced and sensed by driving and sensing elements. Fluid properties are determined from outputs of the sensing elements.

Abstract: A method and device for assessing rheological properties of a fluid, including lubricity and viscosity. The invention utilizes a tube into which the fluid is introduced, and relies on tracking the movement of the fluid through the tube either alone or with one or more particles intentionally introduced into the fluid to assess the rheological properties of the fluid. The method and device generally entail flowing the fluid and the optional suspended particle through a passage within the tube, and assessing a rheological property of the fluid within the tube by tracking the movement of the fluid and/or particle through the portion relative to the flow of the fluid through the portion.

Abstract: A method of treating a bodily fluid withdrawn and then returned to a living body. The method involves withdrawing the bodily fluid from the living body and causing the bodily fluid to flow through a treatment system, altering at least the density of the bodily fluid through the action of a second fluid as the bodily fluid flows through the treatment system, sensing at least the density and flow rate of the bodily fluid before the density thereof is altered by the second fluid, sensing at least the density and flow rate of the bodily fluid after the density thereof is altered by the second fluid, sensing at least the density and flow rate of the second fluid, controlling the density and/or flow rate of the second fluid based on the sensed densities and flow rates, and returning the bodily fluid to the living body.

Abstract: A sensing and analysis system, method, and network that make use of a very portable and compact sensor unit and a physically separate electronic unit that serves to power and control the sensor unit, process and optionally display the output of the sensor unit, and transmit the sensor output to other locations, such as over a network. The sensor unit includes a housing, a sensing element within the housing and responsive to an input, and electronic circuitry within the housing and in communication with the sensing element to produce an electrical output based on an output signal generated by the sensing element. A communication providing device delivers instructions generated by the electronic unit to the sensor unit and delivers the electrical output from the sensor unit to the electronic unit.

Abstract: A device capable of delivering precise amounts of one or more antidotes to treat a victim exposed to biological and chemical agents (biochem agents), and also preferably sensing the presence of biochem agents. The delivery device includes a plurality of reservoirs containing antidotes, a manifold to which the reservoirs are fluidically and removably coupled, an outlet on the manifold, a device for selectively releasing at least one of the antidotes from the reservoirs into the manifold, a device for sensing flow of the at least one released antidote, and a device for stopping flow of the at least one released antidote in response to specified amounts of the at least one released antidote having passed through the flow sensing device.

Abstract: A process for producing a tube suitable for microfluidic devices. The process uses first and second wafers, each having a substantially uniform doping level. The first wafer has a first portion into which a channel is etched partially therethrough between second and third portions of the first wafer. The first wafer is then bonded to the second wafer so that a first portion of the second wafer overlies the first portion of the first wafer and encloses the channel to define a passage. The second wafer is then thinned so that the first portion thereof defines a thinned wall of the passage. Second and third portions of the second wafer and part of the second and third portions of the first wafer are then removed, and the thinned wall defined by the second wafer is bonded to a substrate such that the passage projects over a recess in the substrate surface. The second and third portions of the first wafer are then removed to define a tube with a freestanding portion.

Abstract: A device and method capable of sensing the presence of biochem agents, and preferably also capable of delivering precise amounts of one or more antidotes to treat a victim exposed to the agents. The device includes a freestanding tube portion having an internal passage containing a substance selective to a chemical or biological agent so that matter accumulates within the freestanding tube portion when a fluid drawn through the tube portion contains the agent. When vibrated at resonance, the resonant frequency of the tube portion is indicative of the accumulation of matter and thereby the presence of the agent to which the substance is selective. The device then preferably delivers precise amounts of one or more appropriate antidotes to treat the victim. The device is a sufficiently small and lightweight unit to permit being carried by an individual.

Abstract: A process for producing a tube suitable for microfluidic devices. The process uses a uniformly-doped first material having a first portion into which a channel is etched partially through the first material between second and third portions of the first material. The first material is then bonded to a second material so that a first portion of the second material overlies the first portion of the first material and encloses the channel to define a passage. The second and third portions of the second material and part of the second and third portions of the first material are then removed, and the first portion of the second material is bonded to a substrate such that the passage projects over a recess in the substrate surface. The second and third portions of the first material are then removed to define a tube with a freestanding portion.

Abstract: A device and method capable of sensing the presence of biochem agents, and preferably also capable of delivering precise amounts of one or more antidotes to treat a victim exposed to the agents. The device includes a freestanding tube portion having an internal passage containing a substance selective to a chemical or biological agent so that matter accumulates within the freestanding tube portion when a fluid drawn through the tube portion contains the agent. When vibrated at resonance, the resonant frequency of the tube portion is indicative of the accumulation of matter and thereby the presence of the agent to which the substance is selective. The device then preferably delivers precise amounts of one or more appropriate antidotes to treat the victim. The device is a sufficiently small and lightweight unit to permit being carried by an individual.

Abstract: A fluid system installed on a vehicle and a method for assessing a property of a fluid flowing in the fluid system. The fluid system and method entail flowing at least a portion of the fluid through a passage within a freestanding portion of a micromachined tube supported above a substrate so as to define a gap therebetween, vibrating the freestanding portion of the micromachined tube at a resonant frequency thereof, sensing the movement of the freestanding portion of the micromachined tube so as to measure at least one of the vibration frequency and deflection of the freestanding portion relative to the substrate and produce therefrom at least one output corresponding to at least one of the mass flow rate, specific gravity, and density of the portion of the fluid flowing through the passage, and then using the output to compute the property of the fluid.

Abstract: A microfluidic device and method for assessing properties of a fluid. The device includes a base supported by a substrate and a tube extending from the base and spaced apart from the substrate surface. The tube has an internal passage, first and second portions adjacent the base and defining, respectively, an inlet and outlet of the passage, and a distal portion. A drive electrode is located on the substrate surface adjacent the distal portion of the tube. Sensing electrodes are located on the substrate surface adjacent the first and second portions of the tube, and are adapted for sensing deflections of the first and second portions when vibrated with the drive electrode and from which the fluid property is determined. A pair of electrodes is located on the substrate surface between the drive and sensing electrodes, and are operated to enhance the performance of the microfluidic device, such as by supplementing the drive or sensing electrodes.