A method for detecting at least one gas quantity of at least one predetermined gas by a sensor for measuring a plurality of gases, the sensor comprising a sensitive layer configured to measure the plurality of gases, having an impedance Zs and a heating layer on which the sensitive layer is mounted, the heating layer being configured to be supplied with power in order to vary the temperature of the sensitive layer, the method comprising: a step of supplying the heating layer with at least one voltage ramp defining a linear change in the supply voltage between a low voltage value and a high voltage value, in order to modify the temperature of the sensitive layer during a variation period, a step of measuring variations in the impedance of the sensitive layer at a plurality of temperatures of the sensitive layer during the variation period, so as to detect a plurality of gas quantities, a step of comparing, with a database, at least one variation of the impedance of the sensitive layer measured at a given temperature of the sensitive layer, in order to associate the gas quantity measured with a predetermined gas.

A sensor is driven at a first heating power value. The sensor generates a sensing signal that is indicative of a sensed entity. A possible onset of a sensor contamination condition is detected as a function of the sensing signal generated by the sensor. If such detecting fails to indicate onset of a sensor contamination condition, the sensor continues to be driven at the first heating power value. However, if such detecting indicates onset of a sensor contamination condition, a protection mode is activated. In the protection mode, the sensor is driven at a second heating power value for a protection interval, where the second heating power value is lower than the first heating power value. Furthermore, the operation may refrain from supplying power to the sensor for a further protection interval, wherein the further protection interval is longer than the protection interval.

The present disclosure provides a gas sensor comprising a gas sensing layer fabricated based on a solution-processed, template-free synthesis method that achieves controllable ZnO nanostructured morphologies. The method is based on promotion and suppression of growth at specific crystallographic dimensions by tuning the polarity of the solvent. The gas sensing layer with the ZnO nanostructures exhibits high response, excellent selectivity and rapid recovery time.

The present disclosure is directed to a gas sensor device that includes a plurality of gas sensors. Each of the gas sensors includes a semiconductor metal oxide (SMO) film, a heater, and a temperature sensor. Each of the SMO films is designed to be sensitive to a different gas concentration range. As a result, the gas sensor device is able to obtain accurate readings for a wide range of gas concentration levels. In addition, the gas sensors are selectively activated and deactivated based on a current gas concentration detected by the gas sensor device. Thus, the gas sensor device is able to conserve power as gas sensors are on when appropriate instead of being continuously on.

A dual heater gas sensor module according to an embodiment of the present invention comprises: a housing having a front side and a back side which are partially open and forming the exterior of the dual heater gas sensor module; a first gas sensor for heating the air flowing in through the front side of the housing; and a second gas sensor for measuring a specific gas contained in the air discharging through the backside of the housing, wherein the first gas sensor is located in a first region, the second gas sensor is located in a second region that is higher than the first region, and the first region and the second region may be connected by an inclined plane.

In a gas sensor having a gas-sensitive layer and a heating element to heat the gas-sensitive layer, the heating element comprises a heater track having first and second outer electric terminals and at least one inner electric terminal located between the outer electric terminals. The gas sensor includes a control unit configured to control the electric potentials that are applied to the electric terminals during use, and the control unit is configured to be capable of varying the set of electric potentials applied to the electric terminals. In certain applications the control unit may select the terminals to which power is applied, in order to assure the gas-sensitive layer is heated to a specified temperature. In certain applications the gas sensor has multiple measurement electrodes and the control unit selects the set of electric potentials so that different temperatures are attained at locations where different measurement electrodes are located.

A sensor is driven at a first heating power value. The sensor generates a sensing signal that is indicative of a sensed entity. A possible onset of a sensor contamination condition is detected as a function of the sensing signal generated by the sensor. If such detecting fails to indicate onset of a sensor contamination condition, the sensor continues to be driven at the first heating power value. However, if such detecting indicates onset of a sensor contamination condition, a protection mode is activated. In the protection mode, the sensor is driven at a second heating power value for a protection interval, where the second heating power value is lower than the first heating power value. Furthermore, the operation may refrain from supplying power to the sensor for a further protection interval, wherein the further protection interval is longer than the protection interval.

Problem To extend the life of a MEMS gas sensor.

Solution means A MEMS gas sensor 1 includes an insulator (3), a gas sensitive material (33), a first oxide film (6) and an interlayer insulating film (13), a heater wiring pattern (23), a lower protective film (11), and an upper protective film (20). The insulator includes a cavity (3c). The gas sensitive material (33) is provided corresponding to the cavity (3c). The first oxide film (6) and the interlayer insulating film (13) are provided on the insulator (3) and arranged to overlap each other in a plan view. The heater wiring pattern (23) serves to heat the gas sensitive material (33) and is disposed between the first oxide film (6) and the interlayer insulating film (13). The lower protective film (11) and the upper protective film (20) cover, in direct contact, an upper surface (23c), a lower surface (23d), and a side surface (23e) of the heater wiring pattern (23).

A monolithic gas-sensing chip assembly for sensing a gas analyte includes a sensing material to detect the gas analyte, a sensing system including a resistor-capacitor electrical circuit, and a heating element. A sensing circuit measures an electrical response of the sensing system to an alternating electrical current applied to the sensing system at (a) one or more different frequencies, or (b) one or more different resistor-capacitor configurations of the system. One or more processors control a low detection range of the system to the gas, a high detection range of the system to the gas, a linearity of a response of the system to the gas, a dynamic range of measurements of the gas by the system, a rejection of interfering gas analytes by the system, a correction for aging or poisoning of the system, or a rejection of ambient interferences that may affect the electrical response of the system.

Ultrasensitive, decoupled thermodynamic sensing platforms for the detection of chemical compounds in the vapor phase at trace levels are disclosed, wherein the sensors have a heating resistor decoupled from a sensing resistor. Embodiments of the decoupled sensor comprise a metallic microheater resistor on one side of substrate, and a sensor resistor coupled to a catalyst on the other side of the substrate. A sensor array may be provided including a plurality of sensors each having a different catalyst that, when exposed to an analyte, each experience an endothermic reaction, an exothermic reaction, or no reaction. A comparison of the reaction results to data comprising previously obtained reaction results may be used to determine the presence and the identity of the analyte. Advantageously, the decoupled sensors utilize less power and provide greater sensitivity than other known systems, and may be used to detect and identify a single molecule of an analyte.