45 results about "Chemiresistor" patented technology

Absorbent articles comprising one or more sensors capable of detecting the presence of a body waste in the absorbent article are described. In particular, the absorbent articles comprise at least one chemiresistor capable of detecting the presence of volatile organic compounds associated with a body waste. When a body waste is detected, an indicator means signals a caregiver and / or a user of the absorbent article that an insult has occurred

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.

Absorbent articles comprising one or more sensors capable of detecting the presence of a body waste in the absorbent article are described. In particular, the absorbent articles comprise at least one chemiresistor capable of detecting the presence of volatile organic compounds associated with a body waste. When a body waste is detected, an indicator means signals a caregiver and / or a user of the absorbent article that an insult has occurred.

A flexible chemiresistor (CR) sensor for sensing a molecule of interest in a fluid (liquid or gas) is provided. The flexible CR sensor comprises a flexible chemiresistor (CR) module. The flexible CR module comprises a flexible substrate such polyethylene terephthalate (PET), polyethylene naphthalate (PEN) or polyimide (PI), and a thin film nanoparticle assembly assembled on the flexible substrate. The thin film nanoparticle assembly comprises metal or metal alloy core, ligand-capped nanoparticles and molecular linkers connecting the nanoparticles. The flexible CR sensor and an intelligent pattern recognition engine can be incorporated in a handheld device that can detect a molecule of interest in a fluid (e.g., a liquid or gas) accurately, rapidly, and without false positives. Any sensing array nanomaterial, pattern recognition, and compact / or electronic hardware can be integrated to achieve a desired detection limit and response speed.

The application generally describes devices, systems, and methods for determination of one or more analytes. Embodiments described herein may be useful as sensors for analytes such as explosives, chemical warfare agents, and / or toxins. In some cases, chemiresistor or chemFET sensor devices for monitoring volatile organics, especially chemical warfare agents such as sarin, are described. Some embodiments comprise functionalized carbon nanotube / conjugated polymer composites (6) as sensing material. In some embodiments, the polymer is poly(3-hexylthiophene), 3PHT, optionally substituted with calixarenes, or hexafluoroisopropanol susbstituted polythiophene, HFIP-PT. Biosensing embodiments are also described, as well as methods of manufacturing the devices.

The present invention relates to methods of making compositions for sensor films used for detecting chemical analytes within sensors, such as polymer-absorption chemiresistors (i.e., conductometric sensors). The sensor films have reduced cross-sensitivity to temperature, while maintaining sensitivity to the chemical analytes. The sensor matrix includes components that are associated with a first temperature coefficient of resistance, such as a polymer resin and / or a first conductive particle. The sensor matrix further comprises a second species, preferably a conductive particle, which has a second temperature coefficient of resistance that is opposite to the first temperature coefficient of resistance. The second species has an opposite influence on a resistance response of the sensor from the first species. In this manner, the sensor matrix exhibits a minimized response in resistance to any changes in temperature.

The present invention relates to methods of making compositions for sensor films used for detecting chemical analytes within sensors, such as polymer-absorption chemiresistors (i.e., conductometric sensors). The sensor films have reduced cross-sensitivity to temperature, while maintaining sensitivity to the chemical analytes. The sensor matrix includes components that are associated with a first temperature coefficient of resistance, such as a polymer resin and / or a first conductive particle. The sensor matrix further comprises a second species, preferably a conductive particle, which has a second temperature coefficient of resistance that is opposite to the first temperature coefficient of resistance. The second species has an opposite influence on a resistance response of the sensor from the first species. In this manner, the sensor matrix exhibits a minimized response in resistance to any changes in temperature.

A mechanochemical polymerization method for preparing graphene / metal oxide composite electrode material features that graphite and metal oxide precursor are adde into a mechanochemical reactor as rawmaterials to obtain graphene / metal oxide composite electrode material by one-step mechanochemical reaction. That graphene / metal oxide composite electrode material is prepared by adding graphite and metal oxide precursor as raw material to a mechanochemical reactor. A metal oxide precursor in that invention is a multifunctional reagent, As that ion intercalation agent, Graphene is prepare by accelerating graphite peel under that action of mechanical force, On the other hand, Graphene / metal oxide composite electrode material are obtained by in-situ formation of metal oxide on that surface of graphene due to simultaneous mechanical chemical reaction of metal salts, so that a plurality of processes such as preparation of graphene, in-situ load metal oxide and the like are completed in one step, and the preparation process is simplified, and the preparation efficiency of graphene / metal oxide composite material is improved.

The present invention provides a chemiresistor-based sensor for measuring the presence or amount of analyte in an electrolyte solution; said chemiresistor comprising (i) a chemiresistor film wherein the impedance of said nanoparticle film changes in the presence of an analyte; and (ii) two electrically conducting electrodes in electrical contact with said nanoparticle film; wherein said electrically conducting electrodes are adapted to be connected to a device for measuring the impedance of said chemiresistor film under a voltage signal and wherein the impedance of the double layer capacitor formed by the two electrically conducting electrodes in the presence of the electrolyte solution, is larger than the impedance of the chemiresistor film either before or after exposure of the chemiresistor film to the analyte. A method of using said chemiresistor-based sensor to measure the presence or amount of analyte is also provided. Further provided is a method of determining the partition coefficient of an analyte using said chemiresistor-based sensor.

Incontinence management systems, methods, and sensors are provided that alert the caregiver when a patient's brief has been soiled. A resonant circuit includes a polyaniline / carbon black (PANI / CB) composite chemiresistor which undergoes a large impedance change upon exposure to the vapor or 'smell' of urine or feces. Due to the impedance change of the PANI / CB resistor, characteristics of the resonant circuit change when the sensor is exposed to urine or feces vapor. The sensor responds to an interrogating signal with a signal based least in part on the sensor's impedance and indicates the condition of the brief as soiled or clean.

A chemiresistor sensor system that compensates for changes in resistance caused by changes in ambient temperature, thereby increasing the accuracy of the sensor system's ability to detect target analytes. The sensor system generally includes a first resistor, a second resistor, and a load regulator or switch that is sensitive to changes in ambient temperature. At least one of the first resistor and the second resistor is a sensing element having a resistance that changes in response to the presence of one or more of the analytes. The switch manages an electrical load across the first resistor and the second resistor. The switch prevents passage of the electrical load across the first and / or second resistor when the ambient temperature is at a first value. The switch permits passage of the electrical load across the first and / or second resistor when the ambient temperature is at a second value.

This invention relates to the method for altering the sensitivity and / or the selectivity of the chemiresistor sensor, the sensor and the sensor array manufactured by such a method. The chemiresistor sensor includes a sensing layer having a plurality of conductive particles or semiconductor particles embedded in an electrically nonconductive matrix, and the sensing layer includes a plurality of oxidizable chemical functional groups. This method includes a stage of causing oxidation reaction to the sensing layer. The invention also relates to a sensor and a sensor array produced by the method.

The invention relates to “solid state” chemiresistor sensors with electric control of the affinity of a chemosensitive material. The configurations of the present invention enable the fast regeneration of the sensor after analyte binding, which therefore increases selectivity. In one embodiment the chemiresistor sensor is implemented as a multi-electrode chemiresistor, comprising 4 electrodes for the separate measurement of the resistance of the chemosensitive material and the contact resistance, and 2 further electrodes to control the redox state of the chemosensitive sensor material, thereby facilitating fast and effective regeneration of the sensor.

The present invention provides a chemiresistor-based sensor for measuring the presence or amount of analyte in an electrolyte solution; said chemiresistor comprising (i) a chemiresistor film wherein the impedance of said nanoparticle film changes in the presence of an analyte; and (ii) two electrically conducting electrodes in electrical contact with said nanoparticle film; wherein said electrically conducting electrodes are adapted to be connected to a device for measuring the impedance of said chemiresistor film under a voltage signal and wherein the impedance of the double layer capacitor formed by the two electrically conducting electrodes in the presence of the electrolyte solution, is larger than the impedance of the chemiresistor film either before or after exposure of the chemiresistor film to the analyte. A method of using said chemiresistor-based sensor to measure the presence or amount of analyte is also provided. Further provided is a method of determining the partition coefficient of an analyte using said chemiresistor-based sensor.