Abstract: A method for determining a concentration of a target gas in blood of a human or animal animate being. The method includes the steps of: generating electromagnetic excitation radiation having a carrier frequency, wherein the carrier frequency is selected such that the target gas and an absorbing gas absorb the excitation radiation, modulating an amplitude or the carrier frequency of the excitation radiation with a modulation frequency, illuminating an absorption path superficial to a skin of the animate being with the excitation radiation, generating a sound wave by an absorption of the excitation radiation in the absorption gas, and detecting at least one of an amplitude and a phase of the sound wave as a measure of a concentration of the target gas on the absorption path. Also provided is a photoacoustic sensor for determining a concentration of a target gas in blood of a human or animal animate being.

Abstract: An apparatus for in-situ calibration of a photoacoustic sensor includes a measurement device configured to measure an electric signal at an IR emitter of the photoacoustic sensor, wherein the IR emitter generates an electromagnetic spectrum based on the electric signal; and a calibration unit including processing circuitry, configured to compare the electric signal with a comparison value to generate a comparison result used as calibration information. When performing the in-situ calibration, the calibration unit is configured to adjust the electric signal based on the calibration information, or the calibration unit is configured to process an output signal of the photoacoustic sensor based on the calibration information to obtain an adjusted output signal of the photoacoustic sensor.

Abstract: A gas sensor includes a multi-wafer stack of a plurality of layers and a measurement chamber. The plurality of layers includes a first layer comprising a sensor element that has a microelectromechanical system (MEMS) membrane; and a second layer comprising an emitter element configured to emit electromagnetic radiation. The measurement chamber is interposed between the first layer and the second layer. The measurement chamber is configured to receive a measurement gas and further receive the electromagnetic radiation emitted by the emitter element as the electromagnetic radiation travels along a radiation path from a first end of the measurement chamber to a second end of the measurement chamber that is opposite to the first end.

Abstract: An apparatus for in-situ calibration of a photoacoustic sensor includes a measurement device configured to measure an electric signal at an IR emitter of the photoacoustic sensor, wherein the IR emitter generates an electromagnetic spectrum based on the electric signal; and a calibration unit including processing circuitry, configured to compare the electric signal with a comparison value to generate a comparison result used as calibration information. When performing the in-situ calibration, the calibration unit is configured to adjust the electric signal based on the calibration information, or the calibration unit is configured to process an output signal of the photoacoustic sensor based on the calibration information to obtain an adjusted output signal of the photoacoustic sensor.

Abstract: An apparatus for in-situ calibration of a photoacoustic sensor is provided. The apparatus includes a calibration unit that includes at least one processor configured to calculate calibration information. A light emitter of the photoacoustic sensor is configured to emit an electromagnetic spectrum and the photoacoustic sensor is configured to provide at least two measurement signals based on at least two electromagnetic spectra. The calibration unit is configured to compare the at least two measurement signals to obtain the calibration information and apply the calibration information to the photoacoustic sensor to perform the in-situ calibration.

Abstract: A gas sensor includes a multi-wafer stack of a plurality of layers and a measurement chamber. The plurality of layers includes a first layer comprising a sensor element that has a microelectromechanical system (MEMS) membrane; and a second layer comprising an emitter element configured to emit electromagnetic radiation. The measurement chamber is interposed between the first layer and the second layer. The measurement chamber is configured to receive a measurement gas and further receive the electromagnetic radiation emitted by the emitter element as the electromagnetic radiation travels along a radiation path from a first end of the measurement chamber to a second end of the measurement chamber that is opposite to the first end.

Abstract: A gas sensor includes a multi-wafer stack of a plurality of layers and a measurement chamber. The plurality of layers includes a first layer comprising a sensor element that has a microelectromechanical system (MEMS) membrane; and a second layer comprising an emitter element configured to emit electromagnetic radiation. The measurement chamber is interposed between the first layer and the second layer. The measurement chamber is configured to receive a measurement gas and further receive the electromagnetic radiation emitted by the emitter element as the electromagnetic radiation travels along a radiation path from a first end of the measurement chamber to a second end of the measurement chamber that is opposite to the first end.

Abstract: A gas sensor includes a multi-wafer stack of a plurality of layers and a measurement chamber. The plurality of layers includes a first layer comprising a sensor element that has a microelectromechanical system (MEMS) membrane; and a second layer comprising an emitter element configured to emit electromagnetic radiation. The measurement chamber is interposed between the first layer and the second layer. The measurement chamber is configured to receive a measurement gas and further receive the electromagnetic radiation emitted by the emitter element as the electromagnetic radiation travels along a radiation path from a first end of the measurement chamber to a second end of the measurement chamber that is opposite to the first end.

Abstract: Shown is a wafer arrangement for a gas sensor including a first substrate and a sescond substrate. The first substrate includes a MEMS membrane associated with a sensor element and an emitter element configured to emit electromagnetic radiation. The second substrate is arranged on top of the first substrate and defines at least a portion of a chamber disposed adjacent to the MEMS membrane.

Abstract: An apparatus for in-situ calibration of a photoacoustic sensor is provided. The apparatus includes a light emitter to emit light along a transmission path to a gas and an acoustic sensor element configured to detect an acoustic signal emitted from the gas based on the received light. Furthermore, the apparatus includes a sensing unit configured to detect the light transmitted along the transmission path and to provide an output signal, and a calibration unit to receive the output signal from the sensing unit and to provide a calibration information based on the output signal received from the sensing unit.

Abstract: An apparatus for in-situ calibration of a photoacoustic sensor is provided. The apparatus includes a light emitter to emit light along a transmission path to a gas and an acoustic sensor element configured to detect an acoustic signal emitted from the gas based on the received light. Furthermore, the apparatus includes a sensing unit configured to detect the light transmitted along the transmission path and to provide an output signal, and a calibration unit to receive the output signal from the sensing unit and to provide a calibration information based on the output signal received from the sensing unit.

Abstract: Shown is a wafer arrangement for a gas sensor including a first substrate and a sescond substrate. The first substrate includes a MEMS membrane associated with a sensor element and an emitter element configured to emit electromagnetic radiation. The second substrate is arranged on top of the first substrate and defines at least a portion of a chamber disposed adjacent to the MEMS membrane.

Abstract: Shown is a gas sensor including a sensor element, a measurement chamber and an emitter element. The sensor element has a MEMS membrane which is arranged in a first substrate region. Furthermore, the measurement chamber is embodied to receive a measurement gas.

Abstract: An apparatus for in-situ calibration of a photoacoustic sensor is provided. The apparatus includes a light emitter to emit light along a transmission path to a gas and an acoustic sensor element configured to detect an acoustic signal emitted from the gas based on the received light. Furthermore, the apparatus includes a sensing unit configured to detect the light transmitted along the transmission path and to provide an output signal, and a calibration unit to receive the output signal from the sensing unit and to provide a calibration information based on the output signal received from the sensing unit.

Abstract: Shown is a gas sensor including a sensor element, a measurement chamber and an emitter element. The sensor element has a MEMS membrane which is arranged in a first substrate region. Furthermore, the measurement chamber is embodied to receive a measurement gas.