A combustible gas sensor including a first sensing element having a catalyst and a heating element and electronic circuitry in operative connection with the heating element of the first sensing element to change a temperature thereof between a temperature above a temperature to catalyze oxidative combustion and a temperature at which the catalyst is substantially inactive to catalyze oxidative combustion of a plurality of gas analytes of interest. The electronic circuitry being configured to determine a species of at least one of the plurality of gas analytes of interest from a first, dynamic output of the combustible gas sensor while the temperature of the first sensing element is changing. The electronic circuitry further being configured to determine a concentration of the species from a second output of the combustible gas sensor.

Methods, systems, and devices for detecting an analyte are disclosed and described. In one embodiment, a Metal Oxide Semiconductor (MOS) sensor pixel with a MOS active material is exposed to the analyte in the gas environment. The MOS sensor pixel is heated to a sequence of different predetermined temperatures via a heating element wherein the heating occurs for a period of time for each of the different predetermined temperatures. Response signals are detected, via an electrode, generated by the MOS sensor at each of the different predetermined temperatures. The response signals are assembled into sample data with data features for machine learning. The sample data is compared with data in a standards database. A composition of the analyte is identified based on the data features.

A gas alarm device is provided, where a heating control section extends a heating period of time of a heater section if a first determination section determines that electrical characteristics of a sensing section of a gas sensor satisfy a first condition, and continues extension of the heating period of time of the heater section according to a determination result, by a second determination section, of whether or not the electrical characteristics upon lapse of extension of the heating period of time satisfy a second condition, and a gas detection section determines, according to the electrical characteristics upon lapse of extension time, that detection target gas is detected.

A gallium nitride-based sensor having a heater structure and a method of manufacturing the same are disclosed, the method including growing an n-type or p-type GaN layer on a substrate, growing a barrier layer on the n-type or p-type GaN layer, sequentially growing a u-GaN layer and a layer selected from among an Al.sub.xGa.sub.1-xN layer, an In.sub.xAl.sub.1-xN layer and an In.sub.xAl.sub.yGa.sub.1-x-yN layer on the barrier layer, patterning the n-type or p-type GaN layer to form an electrode, forming the electrode along the pattern formed on the n-type or p-type GaN layer, and forming a sensing material layer on the layer selected from among the Al.sub.xGa.sub.1-xN layer, the In.sub.xAl.sub.1-xN layer and the In.sub.xAl.sub.yGa.sub.1-x-yN layer, wherein a HEMT sensor or a Schottky diode sensor can be heated using an n-GaN (or p-GaN) layer, thus increasing the sensitivity of the sensor and reducing the restoration time.

A combustible gas sensor includes a first sensing element, which includes a catalyst and a heating element in operative connection with the catalyst to heat the catalyst above a temperature to combust gas analytes of interest, and electronic circuitry in operative connection with the heating element of the first sensing element to periodically cycle the first sensing element between a temperature above the temperature to combust the analytes of interest and a temperature at which the catalyst is substantially inactive to catalyze oxidative combustion of the analytes of interest. The electronic circuitry is adapted to determine a species of at least one of the gas analytes of interest from a first output of the combustible gas sensor during an ON time within a cycle duration. The electronic circuitry is further adapted to determine a concentration of the species of gas from a second output of the combustible gas sensor.

A method for operating a semiconductor gas sensor. The semiconductor gas sensor has a sensor element with a sensor material having a semiconductor, a plurality of measuring electrodes electrically connected to the sensor material for exciting and reading the sensor material, and a control and evaluation device for generating excitation signals and evaluating read measurement signals. A surface of the sensor material is exposed to a gaseous medium. In the method, a first excitation signal and a second excitation signal are applied to the sensor material. The excitation signals have different excitation frequencies. A first measurement signal is read based on the first excitation signal, and a second measurement signal is read based on the second excitation signal. A sensor signal is ascertained based on the excitation signals and the measurement signals.

A combustible gas sensor for detecting an analyte gas includes a first element including a first electric heating element, a first support structure on the first electric heating element and a first catalyst supported on the first support structure and electronic circuitry in electrical connection with the first element. The electronic circuitry is configured to operate in a first mode in which the first element is operated at a first temperature at which the first catalyst catalyzes combustion of the analyte gas, and in a second mode wherein the first element is operated at a second temperature which is below the temperature at which the first catalyst catalyzed combustion of the analyte gas but at which Joule heating of the first element occurs. The electronic circuitry is further configured to measure a variable in the second mode related to a mass of the first element.

A control method for gas chemosensors having a sensitive layer, which comprises the steps of: a) measuring the resistivity of the sensitive layer at a particular moment, the sensitive layer being at a particular temperature; b) establishing a temperature profile to be applied to the sensitive layer, based on the resistivity value measured; c) obtaining the average temperature value across the temperature profiles applied to the sensitive layer during a time interval and comparing the average temperature with stored values to determine changes in the gas concentration. The invention also relates to a gas detection system comprising a gas chemosensor connected to control means connected to heating means associated with the sensitive layer, defining a control loop with sigma-delta topology.

The invention relates to a method for the identification of an analyte in a sample fluid. The method comprises the performance of a set of measurements on at least two sensors of different types. Sensors of different types may comprise Gas Chromatography sensors, CMOS gas sensors, a combination thereof, or more generally sensors in which it is possible to control a first physical parameter and measure, for different values of the first parameter, a second physical parameter representative of at least a concentration of the analyte. The method comprises the detection of maxima of the second parameter, the access to databases in order to find reference values of the first parameters in which maxima are found, and the comparison of values at which maxima are found and reference values, on the two sensors.

A fluid sensor comprises a sensor material configured to come into contact at a surface region of same with a fluid and to obtain a first temporal change of a resistance value of the sensor material on the basis of the contact in a first sensor configuration and to obtain a second temporal change of the resistance value of the sensor material on the basis of the contact in a second sensor configuration. The fluid sensor comprises an output element configured to provide a sensor signal on the basis of the first and second temporal change of the resistance value.