Abstract: A compact ceramic fuel property sensor comprises a plurality of laminated ceramic layers. The heater, temperature sensor, and capacitance measurement electrodes are embedded between the layers. The capacitance electrodes include interdigitated electrodes and fuel traps for containing a sample of liquid fuel disposed between the interdigitated electrodes. The dimensions of the fuel traps are selected so that the fuel traps remain filled with liquid after said sensor has been bathed in fuel. A method for monolithically preparing the sensors provides a reduced cost method and a sensor that can survive indefinitely in liquid fuel.

Abstract: A molecular contamination monitoring system includes a piezoelectric measurement sensor exposed to a molecular constituent to be measured; a piezoelectric reference sensor; and a filter for filtering said molecular constituent, the filter located between the reference sensor and the measurement environment. The reference sensor is exposed to the same ambient conditions of temperature, pressure and humidity as the measurement sensor. Alternatively, there may be a plurality of different reference sensors having different filters, or there may be a plurality of different measurement sensors.

Abstract: The invention relates to a process for the detection of hydrocarbons other than methane in a gas predominantly or essentially comprising oxygen, as well as methane and the said hydrocarbons other than methane, the said process comprising: a stage of detection of the combined hydrocarbons in the said gas, providing a first value for the combined hydrocarbons, a stage of combustion of the hydrocarbons other than methane, a stage of detection of methane in the said gas, providing a second value, a stage of calculation of the amount of hydrocarbons other than methane by the difference between the first value and the second value. The invention also relates to a device for implementing this process.

Abstract: A dielectric sensing method and apparatus are provided for detection and classification of chemical and biological materials. Resonance patterns of a sample within a resonator are detected for identifying a shift in resonance frequency and a change of line width before and after introduction of the sample. The identified shift in resonance frequency and change of line width are used for determining a complex dielectric constant of the sample for the material detection and classification. A degree of selectivity at any excitation frequency is enabled for the dielectric sensing method from the manner in which the complex dielectric constant of a material affects the resonance pattern of the resonator with respect to shift in resonance frequency and the change in line width. By selecting the excitation frequencies to generally correspond to one of the resonance frequencies of the sample material under test, the degree of selectivity and the sensitivity of detection are enhanced.

Abstract: The present invention relates to a chemical sensor arrangement having an analyte sensitive indicator wherein the analyte sensitive indicator has at least one nanoparticle. The invention further relates to a method for providing nanoparticles of defined and different sizes, especially for a chemical sensor arrangement, wherein a nanoparticle solution, having nanoparticles of a broad size distribution, is applied to chromatography beads, whereby the nanoparticles are adsorbed onto said beads and classified by size, and beads of a specific layer, having nanoparticles of essentially the same size, are separated from the beads within other layers and are held in suspension.

Abstract: Provided is a gas molecule sensor, characterized in that the sensing element is a polycrystalline tin oxide film having a thickness less than 1 ?m. The sensing element is produced by electrolytic deposit of a tin film on an insulating support in an electromechanical cell, where the anode is comprised of tin and the cathode is a conductive film applied on the surface of the insulating support at one of its ends, the two electrodes being separated by an electrolyte comprised of a tin salt solution, and by passing a constant current through said cell. The deposit step is followed by an oxidizing step.

Abstract: The present invention is a gas detector and method for using the gas detector for detecting and identifying volatile organic and/or volatile inorganic substances present in unknown vapors in an environment. The gas detector comprises a sensing means and a detecting means for detecting electrical capacitance variance of the sensing means and for further identifying the volatile organic and volatile inorganic substances. The sensing means comprises at least one sensing unit and a sensing material allocated therein the sensing unit. The sensing material is an ionic liquid which is exposed to the environment and is capable of dissolving a quantity of said volatile substance upon exposure thereto. The sensing means constitutes an electrochemical capacitor and the detecting means is in electrical communication with the sensing means.

Abstract: A powder filler is stuffed in a filler space defined between a housing and a gas sensing element so as to airtightly seal a clearance between the housing and the gas sensing element. The powder filler contains grains whose diameter is in a range from 80 ?m to 5,000 ?m when measured before being stuffed into the filler space. A weight percentage of the grains having the diameter of 80 ?m to 5,000 ?m is equal to or larger than 80% with respect to an overall weight of the powder filler.

Abstract: A chemical sensing system has: an interrogation unit operable to wirelessly transmit an interrogation signal and wirelessly receive a response; an environmentally sealed container for holding a chemical analyte; a sensor array unit in fluid communication with the analyte disposed within the container, where the sensor array unit is operable to generate a response in the presence of a chemical stimulus; and a passive responder unit connected with the sensor array unit, the responder unit being powered from the interrogation signal, where the responder unit is operable to wirelessly receive the interrogation signal and wirelessly transmit the response to the interrogation signal to the interrogation unit.

Abstract: Devices and techniques for estimating the concentration of one or more agents in a fluid environment employ a plurality of measurements of a sensor attribute that changes in response to an agent. Measurements taken before the agent/reagent combination reaches a steady-state may be used. The plurality of measurements are processed using a nonlinear, parametric model of the interaction between the sensor and the agent to determine the concentration of the agent. The model takes into account the finite capacity of a sensor reagent. The model characterizes the interaction of individual agent/reagent combinations with a set of parameters. These parameters require minimal testing to calculate. The invention enables the response of a sensor to an agent over the entire range of agent concentration levels to be efficiently and accurately characterized. The invention also enables the prediction of collective responses given parameters characterizing a plurality of agent/reagent combinations.

Abstract: An upstream side catalyst and a downstream side catalyst are disposed in an exhaust passage. A first oxygen sensor is disposed between these two catalysts and a second oxygen sensor is disposed downstream of the downstream side catalyst. The air-fuel ratio is forcibly oscillated and the oxygen storage capacity of the upstream side catalyst is detected. Deterioration of the upstream side catalyst is then detected based on whether this oxygen storage capacity is larger than a predetermined value. The forced oscillation of the air-fuel ratio is performed only when the oxygen storage state of the downstream side catalyst is appropriate.

Abstract: A hydrogen sensor includes a first electrode 3 and a second electrode 4 provided in contact with a proton conduction layer 2; a gas diffusion controlling portion 6 provided between a measurement gas atmosphere and the first electrode 3; and a support element (1a, 1b) for supporting the proton conduction layer 6, the first electrode 3, the second electrode 4, and the gas diffusion controlling portion 6. Hydrogen contained in a measurement gas introduced via the gas diffusion controlling portion 6 is dissociated, decomposed, or reacted by applying a voltage between the first electrode 3 and the second electrode 4 to thereby generate protons. Hydrogen concentration is obtained on the basis of a limiting current generated as a result of the generated protons being pumped out via the proton conduction layer 2 from the first electrode 3 side of the proton conduction layer to the second electrode 4 side of the proton conduction layer.

Abstract: Of a gas detector 100, a chamber 105 formed between a center cover 150 and a cover 160 is a part of an air flow channel AF. A first shielding plate 165 is provided in the chamber 105. Water droplets that have entered the chamber from a chamber entrance 103 with air hit and adhere to an entrance-opposed surface 165E of the first shielding plate 165. The water thus adhering to the surface is pushed by the air flowing along the entrance-opposed surface 165E and by gravity, to thereby advance downward. The water then drips downward and is accumulated on a bottom wall surface 105WD which serves as an upper surface of a bottom wall section 161WD. The water is pushed by the flow of air, to thereby advance toward a chamber exit 104. The water is then drained downward from the chamber exit 104.

Abstract: Methods, systems and sensor arrays are provided implementing techniques for detecting an analyte in a fluid. The techniques include providing a sensor array including at least a first sensor and a second sensor in an arrangement having a defined fluid flow path, exposing the sensor array to a fluid including an analyte by introducing the fluid along the fluid flow path, measuring a response for the first sensor and the second sensor, and detecting the presence of the analyte in the fluid based on a spatio-temporal difference between the responses for the first and second sensors.

Abstract: A circular chemiresistor for use in microchemical sensors. A pair of electrodes is fabricated on an electrically insulating substrate. The pattern of electrodes is arranged in a circle-filling geometry, such as a concentric, dual-track spiral design, or a circular interdigitated design. A drop of a chemically sensitive polymer (i.e., chemiresistive ink) is deposited on the insulating substrate on the electrodes, which spreads out into a thin, circular disk contacting the pair of electrodes. This circularly-shaped electrode geometry maximizes the contact area between the pair of electrodes and the polymer deposit, which provides a lower and more stable baseline resistance than with linear-trace designs. The circularly-shaped electrode pattern also serves to minimize batch-to-batch variations in the baseline resistance due to non-uniform distributions of conductive particles in the chemiresistive polymer film.

Abstract: A robust single-chip hydrogen sensor and a method for fabricating such a sensor. By utilizing an interconnect metallization material that is the same or similar to the material used to sense hydrogen, or that is capable of withstanding an etchant used to pattern a hydrogen sensing portion, device yields are improved over prior techniques.

Abstract: A polarization-dependent device is provided that includes organic materials having electric dipoles. The polarization-dependent device comprises: (a) a source region and a drain region separated by a channel region having a length L, formed on a substrate; (b) a dielectric layer on at least a portion of the channel region; and (c) a molecular layer on the dielectric layer, the molecular layer comprising molecules having a switchable dipolar moiety. Addition of a gate over the molecular layer permits fabrication of a transistor, while omission of the gate, and utilization of suitable molecules that are sensitive to various changes in the environment permits fabrication of a variety of sensors. The molecular transistor and sensors are suitable for high density nanoscale circuits and are less expensive than prior art approaches.

Abstract: The present invention relates to compositions which provide an insulated nanoscopic pathway. The pathway comprises molecules, polymers or nanoscopic particles capable of conducting charge integrated with nanoscopic switches which are capable of electronic communication with the charge-conducting species. Turning “on” the nanoscopic switch electronically “connects” the various molecules/particles, such that a continuous nanoscopic pathway results. The nanoscopic pathway can be used in a sensor, where the switches can act as receptors for analytes. Binding of an analyte can result in a variety of effects on the nanoscopic pathway, including altering the conductivity of the nanoscopic pathway.

Abstract: A hydrogen gas sensor and/or switch fabricated from arrays nanowires composed of metal or metal alloys that have stable metal hydride phases. The sensor and/or switch response times make it quite suitable for measuring the concentration of hydrogen in a flowing gas stream. The sensor and/or switch preferably operates by measuring the resistance of several metal nanowires arrayed in parallel in the presence of hydrogen gas. The nanowires preferably comprise gaps or break junctions that can function as a switch that closes in the presence of hydrogen gas.

Abstract: A multi-pin chemiresistor for use in microchemical sensors. A pair of free-standing, bare wires is supported by an electrically insulating support, and are oriented parallel to each other and spaced closely together. A free-standing film of a chemically sensitive polymer that swells when exposed to vapors of a volatile chemical is formed in-between the pair of closely-spaced wires by capillary action. Similar in construction to a thermocouple, this “chemicouple” is relatively inexpensive and easy to fabricate by dipping the pair of bare wires into a bath of well-mixed chemiresistor ink. Also, a chemiresistor “stick” is formed by dipping an electrically insulating rod with two or more linear or spiral-wrapped electrical traces into the bath of well-mixed chemiresistor ink, which deposits a uniform coating of the chemically sensitive polymer on the rod and the electrical traces. These “sticks” can be easily removed and replaced from a multi-chemiresistor plug.

Abstract: The present invention provides a combinatorial approach for preparing arrays of chemically sensitive polymer-based sensors which are capable of detecting the presence of a chemical analyte in a fluid in contact therewith. The described methods and devices comprise combining varying ratios of at least first and second organic materials which, when combined, form a polymer or polymer blend that is capable of absorbing a chemical analyte, thereby providing a detectable response. The detectable response of the sensors prepared by this method is not linearly related to the mole fraction of at least one of the polymer-based components of the sensors, thereby making arrays of these sensors useful for a variety of sensing tasks.

Abstract: A convenient and commonly applicable method for the specific detection of a nucleic acid with an arbitrary sequence is provide. This method comprises attaching at least a nucleic acid single strand to an electrode, bringing the thus-obtained modified electrode in contact with a solution containing the analyte single-stranded nucleic acid, and measuring the redox reaction of the redox marker.

Abstract: The invention is a system (10) and method for determining a gas composition within a fuel cell (12) of a shut down fuel cell power plant. The system (10) includes at least one fuel cell (12), a sensor circuit (86) secured in electrical connection with the fuel cell (12), wherein the circuit (86) includes a power source (88), a voltage-measuring device (90), and a sensor circuit switch (92). The circuit (86) is secured so that the power source (88) may selectively deliver a pre-determined sensing current to the fuel cell (12) for a pre-determined sensing duration. The system (10) selectively admits the reducing fluid into an anode flow field (28) of the cell (12) whenever the sensor circuit (86) senses that a shut down monitoring voltage of the fuel cell (12) is the same as or exceeds a calibrated sensor voltage limit of the fuel cell (12).

Abstract: Chemical sensors for detecting the activity of a molecule or analyte of interest is provided. The chemical sensors comprise and array or plurality of sensors that are capable of interacting with a molecule of interest, wherein the interaction provides a response fingerprint. The fingerprint can be associated with a library of similar molecules of interest to determine the molecule's activity and diffusion coefficient.

Abstract: The present invention is related to the sensing of analytes and in particular, to methods of determining, resolving, identifying, or quantitating such analytes once detected. This invention provides systems and methods for identifying analytes, comprising using an importance index to give greater weight to the responses from sensors that measure characteristics most useful for identification of analytes. In other aspects, the systems and methods are useful for increasing the stability of electronic nose systems by prolonging the predictive capability of the training set of known analytes. In still other aspects, the systems and methods are useful for detecting and responding to events correlated with the presence of an analyte.

Abstract: Sensor arrays and sensor array systems for detecting analytes in fluids. Sensors configured to generate a response upon introduction of a fluid containing one or more analytes can be located on one or more surfaces relative to one or more fluid channels in an array. Fluid channels can take the form of pores or holes in a substrate material. Fluid channels can be formed between one or more substrate plates. Sensor can be fabricated with substantially optimized sensor volumes to generate a response having a substantially maximized signal to noise ratio upon introduction of a fluid containing one or more target analytes. Methods of fabricating and using such sensor arrays and systems are also disclosed.

Abstract: A method for tempering at least one sample wherein an plastic-based electrically conductive material of a specimen carrier consisting at least partially of this material for at least one specimen is applied to by an electric current/an electric voltage which causes a resistance heating of at least one portion of the plastic-based electrically conductive material, which resistance heating heats a specimen disposed on the specimen carrier.

Abstract: A chemiresistor sensor probe for detecting target analytes. The probe includes a body having a first control surface and a second control surface recessed within the first. A sensor film comprises numerous conductive particles disposed upon the second surface. The film swells upon absorbing one or more analytes for which it has an affinity, thus causing the conductive particles to become more dispersed and increasing the resistance between the particles. The thickness of the film is equal to the distance between the first surface and the second surface, thus permitting the thickness to be controlled by varying the distance between the control surfaces. The robustness of the sensor probe is enhanced by placing a porous or mesh electrode along with, or in place of, a chemical binding agent between the film and the terminals. The robustness is also improved by placing a diode in series with the sensor circuit.

Abstract: A lightweight and portable analyzer is provided. At least one component of the analyzer is made from a lightweight material, such as ABS. A manifold can have a plate and gas passages ultrasonically welded together. By having at least one component made from a lightweight material, the analyzer is lighter.

Abstract: A method for mathematically identifying at least one diesel fuel suitable for combustion in an automotive diesel engine with significantly reduced emissions and producible from known petroleum blendstocks using known refining processes, including the use of cetane additives (ignition improvers) and oxygenated compounds.

Abstract: A portable, inexpensive, and easy to operate vehicle oxygen sensor analyzer shows, in real time, on an ultra-bright LED display, the dynamic operation of the oxygen sensor, simulates sensor signals into the computer, while monitoring the oxygen sensor to confirm correct computer operation, and performs a quick, simple and accurate test on the oxygen sensor to prove that it will pass emissions tests for oxygen sensors of the type typically required under emissions control regulations.

Abstract: A liquid electrode mixture for use in a gas sensor having from about 60 to about 240 milligrams of platinum black catalyst; from about 900 to about 1100 milligrams of water; from about 300 to about 400 microliters of 1-propanol; and from about 100 microliters to about 150 microliters of a polymer mixture comprising from about 40% to about 80% PTFE by weight and water.

Abstract: A hydrocarbon sensor and collector. An element that is capable of absorbing and releasing hydrocarbons is positioned in the air intake system of a vehicle, upstream from the engine and wholly in the airflow. The element has a plurality of chambers defined in it that allow air to pass through the element. The hydrocarbon sensor and collector also includes a means for detecting the level of hydrocarbons absorbed by the element.

Abstract: Systems and methods for the ex vivo diagnostic analysis of samples of bodily fluids, including exhaled breath and blood. The present invention uses nanostructure-based assemblies in combination with sensor technology to provide an efficient and accurate means for identifying the presence of a target analyte/biomarker in a sample of bodily fluid. In a preferred embodiment, the nanostructure-based assemblies of the present invention include detecting means such as RNA oligonucleotide chains or “apparatus” and releasable surrogate markers such as DMSO.

Abstract: An analyzing instrument (2) according to the present invention includes a capillary (6), a sample liquid inlet (42), and a liquid introduction controller for a controlled pattern of introduction of the sample liquid into the capillary. The capillary (6) preferably includes a common passage (60) and a plurality of individual passages (61–63) connecting to the common passage. In this arrangement, the liquid introduction controller selects for each of the individual passages (61–63) whether or not the sample liquid is introduced therein. The liquid introduction controller includes, for example, one or more through-holes (51–53) each communicating with e.g. the individual passages (61–63). The liquid introduction controller preferably selects for each of the individual passages (61–63) whether or not the sample liquid is introduced therein, by a selection whether or not the corresponding one of the through-holes (61–63) is opened or closed.

Abstract: A heat generation amount qr/r per unit flow amount of combustible substances supplied to a catalyst is estimated based on upstream and downstream temperature information and supplemental engine information. A deteriorated condition of the catalyst is detected based on a judgement whether or not the estimated heat generation amount is smaller than a predetermined judging value D.

Abstract: A poison resistant combustible gas sensing element, a method for its production and a method for determining poisoning of the element. The element includes an electric heating element, an inner layer coated on the electric heating element and containing a precious metal catalyst supported on a porous oxide, the precious metal catalyst catalyzing combustion of a combustible gas to be detected by the element, and an outer layer overlaying the first layer, and containing a catalytic compound capable of trapping gases which poison the precious metal catalyst, the catalytic compound being supported on a porous oxide.

Abstract: A chemical sensing system has: an interrogation unit operable to wirelessly transmit an interrogation signal and wirelessly receive a response; an environmentally sealed container for holding a chemical analyte; a sensor array unit in fluid communication with the analyte disposed within the container, where the sensor array unit is operable to generate a response in the presence of a chemical stimulus; and a passive responder unit connected with the sensor array unit, the responder unit being powered from the interrogation signal, where the responder unit is operable to wirelessly receive the interrogation signal and wirelessly transmit the response to the interrogation signal to the interrogation unit.

Abstract: A microstructured electrode coupled with an analytical method designed to simulate the actual conditions on the wafer and to measure critical parameters such as mass transfer of the active plating components, deposition rates of the copper in the plating bath solutions, and/or additive concentration is disclosed. Thus, an offline method for process control is provided. Additionally, the electrode and method can be incorporated into a copper interconnect bath tool or copper interconnect bath distribution system for online control of the process chemistry. The microstructured electrode design consists of a patterned electrode surface that simulates the dimensions of the interconnects and vias. The analytical method can be any type of method that allows diffusion or kinetic information to be obtained, such as electrochemical impedance, electrochemical noise, and other voltammetric or galvanostatic methods.

Abstract: Provided is a solid phase array of electrical sensors, each comprising a channel and electrical leads for attaching to a voltage, current or resistivity meter for measuring the voltage, current or resistivity through the pore, wherein the channels are formed of a single substrate.

Abstract: A poison resistant combustible gas sensing element, a method for its production and a method for determining poisoning of the element. The element includes an electric heating element, an inner layer coated on the electric heating element and containing a precious metal catalyst supported on a porous oxide, the precious metal catalyst catalyzing combustion of a combustible gas to be detected by the element, and an outer layer overlaying the first layer, and containing a catalytic compound capable of trapping gases which poison the precious metal catalyst, the catalytic compound being supported on a porous oxide.

Abstract: To measure or exert optically-induced forces on at least one particle in the focus of an optical cage, the following steps are taken: a) the focus is positioned in a microelectrode arrangement with a three-dimensional electrical field that has a field gradient which forms an electrical capture area, and the focus is at a distance from the capture are and b) the amplitude of the electrical field, the light power of the light beam forming the optical cage, and/or the distance of the capture area from the focus are varied to detect which varied field property moves the particle from the focus to the capture area or vice versa, or at least to temporarily move the particle into the capture area.

Abstract: Methods, systems and sensor arrays are provided implementing techniques for detecting an analyte in a fluid. The techniques include providing a sensor array including at least a first sensor and a second sensor in an arrangement having a defined fluid flow path, exposing the sensor array to a fluid including an analyte by introducing the fluid along the fluid flow path, measuring a response for the first sensor and the second sensor, and detecting the presence of the analyte in the fluid based on a spatio-temporal difference between the responses for the first and second sensors.

Abstract: Disclosed herein is a method and apparatus for analyzing, sensing and measuring the concentrations of various gases, including NOx, hydrocarbons, carbon monoxide and oxygen, in a multi-component gas system using chemical sensors and chemical sensor arrays. The sensors and sensor arrays use chemo/electro-active materials to analyze and detect the presence of gases.

Abstract: An array of piezoelectric resonators used in a sensor device in order to identify chemical and biological agents. The resonators can operate as bulk acoustic wave (BAW), surface acoustic wave (SAW), or Love mode devices. The sensor device integrates gravimetric, calorimetric, thermal gravimetric, voltage gravimetric and optical detection methods into one sensor system, improving the accuracy of identifying hazardous agents. For gravimetric detection, dual-mode resonators provide simultaneous calorimetric and gravimetric data, one type from each mode. Resonators with heaters on the surfaces will provide thermal gravimetric data. An optical detector can be used to analyze the optical signal from the surface of a coated resonator. Additionally, voltage gravimetric measurements can be made with an electric field set up between the resonator and an external electrode. Thermal voltage gravimetric measurements can be made by adding an integrated heater on the resonator with an external electrode.

Abstract: An electrode system, particularly for installation in an exhaust line, has a holding body made of an insulating material, on which at least one operating electrode is positioned. The holding body has a heating device for facilitating easy cleaning in the installed position.

Abstract: A diagnostic system for monitoring catalyst performance in an exhaust system comprises a plurality of treatment devices catalytically treating an exhaust gas stream, and a plurality of gas sensors for monitoring the catalyst performance of the treatment devices to determine when sulfur poisoning occurs. An on-board diagnostic system receives signals from the gas sensors, and, based upon response time differentials between sensors, determines whether the treatment devices are experiencing sulfur poisoning.

Abstract: The invention relates to a method and apparatus for providing a reactor having a heater, a passage for transporting a reactant, and a chamber containing a gas sample and being coupled to the passage for receiving the reactant and mixing the reactant with the gas sample. The reactor further includes a connector leading from the chamber to the heater for transporting a mixture of the reactant and gas sample, and wherein the heater heats the mixture of the reactant and gas sample.

Abstract: Sensor arrays, methods, and systems for detecting the presence of gas phase materials by the formation of films based on the gas phase material are disclosed. The gas phase materials preferentially deposit conductive films on receptor materials that can be detected. The invention may also provide for increased sensitivity to the deposition of conductive materials through the use of closely spaced conductive electrodes interconnected by lines of receptor material. Examples of gas phase materials that may be detected include RuO4, IrO4 and RhO4.

Abstract: A process is described, and also the system for its embodiment, for the determination of pollution by MTBE in the soil and in the overlying atmosphere. An example is described relating to the monitoring of underground fuel tanks for autotraction containing an oxygenated additive.