An integrated sensor for detecting gases present in an environment is provided. The integrated sensor comprises a first gas sensor and a second gas sensor. The first gas sensor is configured to measure a first gas and the second gas sensor is configured to measure a second gas. The first gas is different from the second gas. The first gas sensor is an optical sensor and defines an optical cavity. The second gas sensor is disposed within the optical cavity of the first gas sensor.

A chemical sensor (10) is described with at least one layer of a metal oxide (11) arranged between two current injecting electrodes (16,16′) with the length (L) of the layer of a metal oxide between the current injecting electrodes being less than 50 microns and one or a pair of voltage sensing electrodes (17) connected to the layer of a metal oxide (11) with the electrodes (16,16′,17) forming a 3- or 4-terminal arrangement for determining the resistance changes of layer material (11) excluding series resistances such as contact resistances close to or at at least one of the current injecting electrodes (16) from the resistance measurement.

The inventors experimentally demonstrated NO.sub.2 gas sensing performance of multilayer black phosphorous (BP) field effect transistors. The BP sensors were sensitive to NO.sub.2 concentration down to 5 ppb making them comparable in sensitivity to the best 2D material based sensors. Raman spectroscopy comparison revealed no apparent change in the spectra before and after exposure to NO.sub.2, which shows that thick BP flakes can maintain their relative stability after sensing. Moreover, the BP device sensing performance fitted well with the Langmuir Isotherm for molecules adsorbed on a surface, which confirms charge transfer as the dominant mechanism for sensing. The systematic increase in conductance with increasing NO.sub.2 concentrations suggests NO.sub.2 molecules withdraw electrons and dope BP flakes with holes. These results lay the ground work for BP to be applied to various sensing applications including chemical, gas, and bio-sensors.

A gas sensor array containing a gas flow path in which a gas to be analyzed flows, and a plurality of gas sensors set along the gas flowing direction of the gas flow path, wherein the gas sensors each has a constitution wherein semiconductor microcrystals that come into contact with the gas to be analyzed that flows in the above gas flow path are disposed between two electrodes.

An apparatus comprises a load resistance connectable in series with the electronic sensor to form a series resistance of the load resistance and the internal impedance of the electronic sensor; an excitation circuit configured to apply a predetermined voltage to a circuit element; and a measurement circuit configured to: initiate applying the predetermined voltage to the series resistance and determining the series resistance; initiate applying the predetermined voltage to the load resistance and determining the load resistance; and calculate the internal impedance of the sensor using the determined series resistance and the load resistance, and provide the calculated internal impedance to a user or process.

A measurement circuitry (MC) for evaluating a resistance of a resistive gas sensor (GS) comprises a first current path (P1), wherein a first logarithmic compression circuit (LC1) is arranged in the first current path (P1). A reference resistor (Rreference) and a second logarithmic compression circuit (LC2) is arranged in a second current path (P2) of the measurement circuitry (MC). A voltage generator (VG) provides a fixed voltage excitation for the resistive gas sensor (GS) and the reference resistor (Rreference). A first current (I1) received from the resistive gas sensor (GS) flows from the gas sensor (GS) via the first current path (P1) into the first logarithmic compression circuit (LC1). An evaluation circuit (EC) determines the resistance (Rs) of the resistive gas sensor (GS) in dependence on a first and second output signal (Ve1, Ve2) of the first and the second logarithmic compression circuit (LC1, LC2).

A wireless sensor platform design and a single walled carbon nanotube/ionic liquid-based chemidosimeter system can incorporated into a highly sensitive and selective chemical hazard badge that can dosimetrically detect an analyte down to a sub parts-per-million concentration.

A sensor system in a package, comprising: a package, the package including: a sensor chip comprising sensor array comprising a plurality of sensing elements, wherein each of the plurality of sensing elements are functionalized with a deposited mixture consisting of hybrid nanostructures and a molecular formulation specifically targeting at least one of a plurality of gases, and wherein each of the plurality of sensing elements comprises a resistance and a capacitance, and wherein at least one resistance and capacitance are altered when the interacting with gaseous chemical compounds; and a mixed signal System on a Chip (SoC), comprising an analog signal conditioning and Analog-to-Digital conversion circuit configured to convert the analog signal into a digital signal, and a low-power processor circuit configured to processes the digital signal using a pattern recognition system implementing gas detection and measurement algorithms.

A gas sensor comprises a set of one or more sensor cells (SC) and a substrate (1). Each sensor cell (SC) of the set comprises a sensitive film (42) built from a sensitive material (4) covering an area of the substrate (1). One or more elevated structures (2) are manufactured in or around said area for preventing the sensitive material (4) to expand when being applied thereto.

A method for precise acquisition of a signal of a sensor, by an evaluation and control unit which has a multiplexer at whose inputs there is at least one reference voltage whose voltage value is known, a ground potential of the reference voltage, a measurement signal of the exhaust gas sensor, and a ground potential of the measurement signal. A computer is connected downstream from the multiplexer via a transmission path and via an ADC that converts a voltage between its two inputs into a digital value. The method provides that a plurality of individual measurements are carried out in which switching states of the multiplexer are modified, and digital values are subsequently acquired at the output of the ADC. The computer calculates a measurement value, corrected with regard to offset and gain, from these digital values.