Sensor device, and method for sensing the amount or concentration of a target fluid in a medium using the sensor device

Abstract

The sensor device includes a first micropump having a normally closed safety valve located at the outlet of the micropump, a second micropump having a normally closed safety valve located at the outlet of the micropump, and a sensor having a sensor chamber, the sensor chamber having a sensor element (e.g., an active sensitive area or layer) located in the sensor chamber, wherein the sensor is configured to provide a sensor output signal based on a state of a fluid (e.g., a gas or liquid) in the sensor chamber. The sensor chamber is fluidly coupled between the first and second micropumps, and the first and second micropumps are configured to provide a defined operating mode of the sensor device based on corresponding activation or operating states of the first and second micropumps to provide: (1) a defined negative fluid pressure in the sensor chamber, (2) a defined positive fluid pressure in the sensor chamber, or (3) a defined fluid flow rate, such as a defined fluid throughput, through the sensor chamber.

Description

Technical Field

[0001] Embodiments of the present invention relate to a sensor device and a method for sensing the amount or concentration of a target fluid in a medium using the sensor device. More specifically, embodiments relate to a micro pump with a gas sensor, and in particular, to a fluid concept using a micro pump with a safety valve for a gas sensor.

[0002] Gas sensors can detect molecules by interaction between them and the sensitive sensor layer of the gas sensor. The processes of adsorption and desorption of different gas molecules from the sensor layer affect the sensitivity, specificity and drift of the gas sensor. These adsorption and desorption mechanisms can be affected, for example, by heating the sensor layer, where heating the sensor layer generally increases the desorption of molecules. Pumps or micropumps can support these processes by transporting the gas molecules to or away from the sensor layer in a defined manner.

[0003] Reducing the gas pressure in the sensor chamber of the pump or micropump may support regeneration of the sensor layer, eg remove the gas molecules from the sensor layer (= desorption). Background Art

[0004] Among the implementations of suitable sensors that may be used within mobile devices, the sensing of environmental parameters in the ambient atmosphere, such as ambient gas composition, is of increasing importance.

[0005] For example, WO2015104221 A1 relates to a gas measuring device having a sensor unit for detecting a gas, the sensor unit comprising a pressure-tight measuring channel, a gas inlet for introducing the gas into the measuring channel, a gas outlet for discharging the gas from the measuring channel, and a pump unit for evacuating the measuring channel. The measuring channel has a gas sensor for detecting the gas and an electric heating element for heating the gas sensor. The sensor unit can be operated in a measuring mode and a regeneration mode, wherein in the regeneration mode the measuring channel is evacuated and the gas sensor is heated.

[0006] Thus, the pump, together with the active valve, generates a negative pressure in the chamber (measurement channel) at the sensor layer to support the gas sensor during regeneration mode. To this end, a heater is also implemented to heat the gas sensor for regeneration. The negative pressure (relative to atmospheric pressure) together with the heating is intended to improve the sensor regeneration.

[0007] However, the known prior art has many disadvantages and limitations.

[0008] Typically, the large dead volume of the gas pump at the sensor chamber has the following disadvantages: a large and powerful pump is required to generate the desired pressure (e.g., negative pressure) within a certain time, or to generate a higher flow rate to purge the dead volume. The active valve then moves a switching volume as it moves the gas.

[0009] Therefore, known implementations of gas sensors include large and bulky arrangements. Such arrangements are difficult to implement in mobile devices. In addition, such gas sensors have large dead volumes when transferring gas to the sensor chamber and transferring the gas away from the sensor chamber. In addition, in the case of a pump and an active valve, only negative pressure (pump located before the sensor chamber and valve located after the sensor chamber) or overpressure (pump located after the sensor chamber and valve located before the sensor chamber) can be achieved.

[0010] Generally, there is a need in the field of gas sensors to provide an improved concept for a gas sensor which can be easily integrated into a mobile device.

[0011] Such a need can be solved by the sensor device according to claim 1 and the method for sensing the amount or concentration of a target fluid in a medium according to claim 27 .

[0012] Furthermore, specific implementations of the sensor device and the method are defined in the dependent claims. Summary of the invention

[0013] According to an embodiment, a sensor device includes a first micropump (e.g., a microfluidic or peristaltic pump) having, for example, a normally closed (NC) safety valve located at the outlet of the micropump, a second micropump (e.g., a microfluidic or peristaltic pump) having, for example, a normally closed (NC) safety valve located at the outlet of the micropump, and a sensor having a sensor chamber (e.g., a sensor chamber or a sensor volume) having a sensor element (e.g., an active sensitive area or layer) located in the sensor chamber, wherein the sensor is configured to provide a sensor output signal based on the state of the fluid (e.g., gas or liquid) in the sensor chamber. The sensor chamber of the sensor is fluidically coupled between the first micropump and the second micropump, and the first micropump and the second micropump are configured to provide a defined operating mode of the sensor device based on the corresponding activation or operating states of the first micropump and the second micropump to provide: (1) a defined negative fluid pressure in the sensor chamber; (2) a defined positive fluid pressure in the sensor chamber; or (3) a defined fluid flow rate, such as a defined fluid throughput, through the sensor chamber.

[0014] The proposed inventive concept for a sensor device and for sensing the amount or concentration of a target fluid in a medium with the sensor device is based on the following discovery: the sensor device has two micropumps (e.g., two microfluidic or peristaltic pumps), each micropump having a normally closed safety valve, wherein the fluid sensor (e.g., a gas or liquid sensor) is arranged in a sensor chamber, the sensor chamber being fluidically coupled between the two micropumps and separated to be sealed relative to the environment. Since the two micropumps are arranged in a fluidic series connection and have the same fluid pumping direction, both negative and positive fluid pressures can be generated in the enclosed sensor chamber.

[0015] Based on this implementation of the sensor device, a compact solution for the gas sensor can be achieved, wherein the sensor device can achieve negative or positive pressure in the sensor chamber in a component that is as small and flat as possible, and the sensor device can also be easily integrated into a mobile device.

[0016] According to further embodiments, the first micropump comprises a pump inlet, a pump chamber, and a pump outlet, wherein the first micropump is configured to pump the fluid (e.g., ambient air) from the pump inlet through the pump chamber to the pump outlet, wherein the second micropump comprises a pump inlet, a pump chamber, and a pump outlet, wherein the second micropump is configured to pump the fluid from the pump inlet through the pump chamber to the pump outlet, and wherein the sensor chamber is fluidically coupled between the pump outlet of the first micropump and the pump inlet of the second micropump and is separated so as to be sealed (e.g., airtight or encapsulated) relative to the environment.

[0017] Thus, the sensor device comprises a sealed or encapsulated sensor chamber. The encapsulated sensor chamber provides a defined sensor volume during measurement, which is enclosed with respect to the surrounding atmosphere outside the gas sensor. Thus, if the micropump is switched off, disturbing convection can be avoided, which leads to good conditions for gas measurement.

[0018] According to an embodiment, the first micropump and the second micropump, the sensor and optionally the processing device can be integrated into a semiconductor substrate, such as a silicon substrate. The integration of the sensor device (or at least a large part thereof) in the semiconductor substrate allows providing a relatively small dead volume or dead zone of the micropump in the range of about a few μl (microliters) (for example, in the range between 1 μl and 10 μl). Based on the relatively small dead volume of the micropump, the measuring time and the measuring accuracy of the fluid sensor can be increased (improved), wherein, in addition, the calibration of the fluid sensor can be significantly improved. In addition, if sharp corners or ridges in the fluid channel of the fluid sensor can be avoided (at least partially), the dispersion of the fluid or fluid particles flowing through the fluid sensor can be avoided (minimized) or at least reduced.

[0019] According to a first operating mode of the sensor device, a vacuum mode can be implemented in the sensor chamber by means of the first micropump and the second micropump. In the first operating mode, the first micropump is in an off state, for example, in a closed state or deactivated, and the second micropump is in an on state, for example, in an open state, activated or energized to provide a defined negative fluid pressure in the sensor chamber.

[0020] The second micropump may be optimized to provide a high negative pressure (relative to atmospheric or ambient pressure). If a high negative pressure is achieved, the sensor device may be calibrated very effectively, for example in combination with heating of the fluid sensor element (eg gas sensing membrane).

[0021] According to a second operating mode of the sensor device, an overpressure mode can be implemented in the sensor chamber by means of the first micropump and the second micropump. In the second operating mode, the first micropump is in an on-state and the second micropump is in an off-state to provide a defined positive fluid pressure in the sensor chamber.

[0022] The first micropump can be optimized to provide a high positive pressure. An optional pressure sensor can, for example, measure the pressure in the sensor chamber as a reference value for the sensor reading and as feedback for setting a certain pressure in the sensor chamber. In addition, a high or increased pressure in the sensor chamber can improve the binding process of the target fluid with the sensor element in the sensor chamber. The integration of a pressure sensor (e.g., a piezoelectric element) in the sensor chamber allows the pressure in the sensor chamber to be controlled and enables very accurate measurements.

[0023] According to further embodiments, the second operating mode may include a first partial operating mode and a subsequent second partial operating mode, wherein in the first partial operating mode, the first micropump is in an on-state and the second micropump is in an off-state to provide a defined positive fluid pressure in the sensor chamber. In the (immediately) subsequent second partial operating mode, the first micropump is switched to an off-state and the second micropump is kept in an off-state to provide a defined amount of fluid in the sensor chamber (e.g., in the fluid path and the sensor chamber), i.e., a defined fluid volume or a defined measurement volume. Thus, the sensor element can interact with a defined amount of "loaded" fluid input to the sensor chamber.

[0024] According to a third operating mode of the sensor device, a purge mode can be implemented in the sensor chamber by means of the first micropump and the second micropump. In the third operating mode, the first micropump is in an on state and the second micropump is in an on state to provide a defined fluid flow through the sensor chamber (e.g., with a defined fluid throughput). The purge mode of the sensor device can provide an effective calibration, for example, again in combination with a heating of the fluid sensor element.

[0025] According to further embodiments, the sensor device may include a pressure sensor which is located in the sensor chamber or is fluidically coupled to the sensor chamber to measure the pressure of the fluid in the sensor chamber.

[0026] In general, if the pressure at the sensor element (e.g., the gas sensor layer) can be adjusted, this feature can be used to obtain more specific sensor feedback. More specifically, gas measurements at a certain pressure level result in specific binding of gas molecules at the sensor element, thereby enabling specific gas measurements. Thus, providing the pressure sensor allows the pressure at the sensor element (gas sensor membrane) to be changed, so that a pressure-dependent fluid (gas) absorption curve or profile can be detected.

[0027] According to further embodiments, the first micropump may include a plurality of micropump elements arranged in cascade (e.g., fluidly connected in series) to provide an increased positive fluid pressure in the sensor chamber, and / or fluidly connected in parallel to provide an increased fluid throughput through the sensor chamber.

[0028] According to further embodiments, the second micropump may include a plurality of micropump elements in a cascade arrangement to provide an increased negative fluid pressure in the sensor chamber and / or to provide an increased fluid throughput through the sensor chamber.

[0029] According to further embodiments, the sensor device may (alternatively or additionally) comprise a heating element, which is arranged in the sensor chamber or is thermally coupled to the sensor chamber to heat the fluid, e.g. to adjust the temperature of the fluid in the sensor chamber and / or the temperature of the sensor element of the sensor. Thus, the heating element may provide different measurement temperatures in the sensor chamber. Furthermore, the heating element may provide or at least support a "reset" (regeneration or recovery) of the sensor element (e.g., active sensor area).

[0030] According to further embodiments, the sensor device may include a temperature sensor which is located in the sensor chamber or is thermally coupled to the sensor chamber to measure the temperature in the sensor chamber.

[0031] As indicated above, pressure dependent fluid (gas) absorption curves can be detected, wherein the provision of the temperature sensor and / or heater can provide temperature regulation of the fluid in the sensor chamber. Temperature / pressure matrix measurements enable detection of specific molecules from the matrix, for example by pattern recognition, based on the controlled temperature and pressure in the sensor chamber.

[0032] According to further embodiments, the sensor device may include a processing device, such as a controller or an ASIC, configured to control the operating mode of the first and second micropumps, and to read out the sensor output signal of the sensor in the set or adjusted operating mode. Thus, the processing device is configured to control the operating mode of the heating element, and to read out the pressure sensor and / or the temperature sensor of the sensor chamber coupled to the sensor.

[0033] According to another embodiment, the processing device can be configured to: (1) control the operating mode of the first micropump and the second micropump to adjust the fluid pressure in the sensor chamber and / or the fluid throughput or fluid flow through the sensor chamber; (2) control the heating element to adjust the temperature of the fluid in the sensor chamber and / or the different or varying temperatures of the sensor element; and (3) read out the sensor output signal at different temperatures.

[0034] According to a further embodiment, the processing device can also be configured to determine a sensor matrix comprising information (1) relating to the read-out sensor output signal, information (2) relating to the (e.g., different) operating modes of the first micropump and the second micropump, and information (3) relating to different temperatures in the sensor chamber.

[0035] According to further embodiments, the processing device may further be configured to determine a sensor matrix comprising information related to the measured pressure in the sensor chamber.

[0036] According to further embodiments, the processing device may also be configured to determine a sensor matrix comprising information relating to a defined fluid flow rate through the sensor chambers (eg having a defined fluid throughput).

[0037] In summary, the processing device can set different states in the sensor chamber, for example, one of different operating modes, temperature and / or fluid pressure in the sensor chamber, and can interpret the sensor signal based on the set state in the sensor chamber. This approach enables the expansion of the parameter room (parameter space): from temperature T (with a heater) to parameter pressure P (which can be adjusted), and also to flow rate Q (generated by the micro pump during the set operating mode (e.g., the purge mode, the vacuum mode or the overpressure mode)).

[0038] Thus, the proposed sensor concept enables numerous possibilities to improve the interpretation of the sensor signal with regard to sensitivity and specificity.

[0039] According to further embodiments, the processing device may be configured to provide a regulated actuation with a rectangular or sinusoidal actuation signal to the first and second micropumps.

[0040] According to further embodiments, the processing device may also be configured to determine the presence, amount or concentration of the target fluid in the fluid in the sensor chamber based on the resulting pressure oscillation curve of the fluid (e.g., having the target fluid) in the sensor chamber.

[0041] Furthermore, the proposed sensor concept also allows using the properties of the sensor device to interpret the sensor signal with regard to sensitivity and specificity.

[0042] More specifically, different time constants for pressurization (and vacuum build-up) in the sensor chamber can enhance the effectiveness of specific gas measurements. This can be achieved by slowing down or speeding up the pumping to fill / empty the sensor chamber.

[0043] The same is true for dynamic pressure buildup / vacuum establishment (pressure cycling). Different behavior for changing gas concentrations is expected. However, adjusted actuation (e.g., rectangular actuation) may cause oscillations of membranes, (even gas sensing membranes), safety valve membranes, or / and molecules in the system and may adversely affect or impact the sensing process.

[0044] According to an embodiment, the sensor element is sensitive to a chemical or physical state of the fluid in the fluid chamber. The sensor element may be sensitive to a concentration of a target fluid or a target gas in the fluid in the sensor chamber. The sensor element may be sensitive to the presence, amount and / or concentration of a target gas in a gas in the sensor chamber, wherein the target gas includes VOC (VOC=volatile organic compounds), CO X (e.g., CO or CO2, O X (e.g., O2 or O3) or NO X The sensor element may be sensitive to VOCs (e.g., NO or NO2). The sensor element may be a VOC sensor based on metal oxides (e.g., MOX or metal oxide semiconductors). The sensor element may be an electrochemical sensor with a liquid or solid electrolyte material. In addition, the sensor element may be sensitive to the concentration of particulate matter in the fluid (e.g., ambient gas or ambient air) in the sensor chamber.

[0045] According to another embodiment, a method for using the above sensor device to sense the amount or concentration of a target fluid in a medium (e.g., a carrier fluid or an ambient medium), the method comprising the following steps: adjusting the operating mode of a first micropump and a second micropump, for example with the aid of a processing device; and reading out the sensor output signal of the sensor in the adjusted operating mode, for example with the aid of a processing device.

[0046] According to an embodiment, the method may further include the following steps: adjusting or changing the temperature of the fluid in the sensor chamber and / or the temperature of the sensor element of the sensor, for example by means of a heating element arranged in the sensor chamber or thermally coupled to the sensor chamber, so as to provide different measurement temperatures in the sensor chamber; measuring the temperature in the sensor chamber, for example by means of a temperature sensor located in the sensor chamber or thermally coupled to the sensor chamber; and reading out the sensor output signal at different temperatures, for example by means of the processing device.

[0047] According to an embodiment, the method may further include the following steps: adjusting the fluid pressure in the sensor chamber and / or the fluid throughput (e.g., the fluid flow rate) through the sensor chamber to provide different fluid pressures in the sensor chamber and / or different fluid throughputs (e.g., fluid flow rates) through the sensor chamber; measuring the fluid pressure in the sensor chamber and / or the fluid throughput (e.g., the fluid flow rate) through the sensor chamber, for example, by means of a pressure sensor arranged in the sensor chamber or fluidically coupled to the sensor chamber; and reading out the sensor output signal under different fluid pressures in the sensor chamber and / or the fluid throughputs through the sensor chamber, for example, by means of the processing device.

[0048] According to an embodiment, the method may further comprise the following steps: for example, determining, by means of the processing device, a sensor output signal matrix comprising information (1) relating to the read sensor output signal and information (2) relating to the operating modes (e.g., different operating modes) of the first micropump and the second micropump.

[0049] According to an embodiment, the method may further comprise the step of determining the sensor matrix comprising information (3) relating to different temperatures in the sensor chambers, for example by means of the processing device.

[0050] According to an embodiment, the method may further comprise the step of determining the sensor matrix comprising information (4) relating to the measured pressure in the sensor chamber, for example by means of the processing device.

[0051] According to an embodiment, the method may further comprise the step of determining the sensor matrix comprising information (5) about a defined fluid flow rate (eg having a defined fluid throughput) through the sensor chambers, for example by means of the processing device.

[0052] According to an embodiment, the method may further include the following steps: determining the presence, amount or concentration of the target fluid in the fluid in the sensor chamber based on the obtained sensor output signal matrix, for example with the aid of the processing device, wherein the sensor matrix provides multiple parameter values ​​for each sensor output value, such as temperature and / or pressure and / or fluid flow. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] In the following, embodiments of the present disclosure are described in more detail with reference to the accompanying drawings, in which:

[0054] Figure 1 shows a schematic cross-sectional view of a sensor device 100 according to an embodiment;

[0055] Figure 2A-2E shows different operating modes of the sensor device 100 according to further embodiments; and

[0056] Figure 3 A schematic block diagram of a method 300 for sensing the amount or concentration of a target fluid in a medium using the sensor device according to an embodiment is shown.

[0057] In the following description, the embodiments are further discussed in detail using the drawings, wherein in the drawings and the specification, the same elements or elements having the same function and / or the same technical or physical effect are provided with the same reference numerals or identified by the same name. Thus, the descriptions of these elements and their functions illustrated in different embodiments can be interchangeable or can be applied to each other in different embodiments. DETAILED DESCRIPTION

[0058] In the following description, embodiments are discussed in detail, however, it should be understood that the embodiments provide many applicable concepts that can be embodied in a variety of semiconductor devices. The specific embodiments discussed only illustrate specific ways to make and use the current concepts, and do not limit the scope of the embodiments. In the description of the following embodiments, the same or similar elements having the same functions have the same reference numerals or the same name, and the description of such elements will not be repeated for each embodiment. In addition, unless explicitly stated otherwise, the features of the different embodiments described below may be combined with each other.

[0059] It should be understood that when an element is referred to as being "connected" or "coupled" to another element, it may be directly connected or coupled to the other element, or there may be intervening elements. Conversely, when an element is referred to as being "directly" connected to another element, "connected" or "coupled," there are no intervening elements. Other terms used to describe relationships between elements should be interpreted in a similar manner (e.g., "between" versus "directly between," "adjacent" versus "directly adjacent," and "on" versus "directly on").

[0060] For the convenience of describing different embodiments, the drawings comprise a Cartesian coordinate system x, y, z, wherein the zy plane corresponds to (i.e. is parallel to) a first main surface area of ​​the substrate (=reference plane=xy plane), wherein the direction vertically upwards relative to the reference plane (xy plane) corresponds to the "+z" direction, and wherein the direction vertically downwards relative to the reference plane (xy plane) corresponds to the "-z" direction. In the following description, the term "lateral" means a direction parallel to the x-direction and / or the y-direction (i.e. parallel to the xy plane), wherein the term "vertical" means a direction parallel to the z-direction. Figure 1 and Figure 2A-2E , the drawing plane is parallel to the xz plane.

[0061] Figure 1 A schematic cross-sectional view of a sensor device 100 according to an embodiment is shown, wherein Figure 2A-2E Different operating modes and states of sensor device 100 are shown.

[0062] According to an embodiment, the sensor device 100 comprises a first micropump 10, such as a microfluidic or peristaltic pump / micropump, which has, for example, a normally closed (NC) safety valve 11 at a micropump outlet 12 of the first micropump 10. According to an embodiment, the sensor device 100 further comprises a second micropump 20, such as a microfluidic or peristaltic pump / micropump, which has, for example, a normally closed (NC) safety valve 21 at a micropump outlet 22 of the second micropump 20. The sensor device 100 further comprises a sensor 30, the sensor 30 having a sensor chamber 31 (e.g., a sensor chamber or sensor volume) and having a sensor element 32, such as an active sensitive area or layer, in the sensor chamber 31, wherein the sensor 30 is configured to provide a sensor output signal based on a state (e.g., a chemical or physical state) of a fluid (=gas or liquid) in the sensor chamber 31.

[0063] like Figure 1 As shown, the sensor chamber 31 of the sensor 30 is fluidically coupled between the first micropump 10 and the second micropump 20. The first micropump 10 and the second micropump 20 are configured to provide a defined operating mode of the sensor device 100 based on the corresponding startup or operating states of the first micropump 10 and the second micropump 20 to provide: (1) a defined negative fluid pressure in the sensor chamber; (2) a defined positive fluid pressure in the sensor chamber; or (3) a defined fluid flow rate through the sensor chamber, such as a defined fluid throughput.

[0064] According to an embodiment, the first micro pump 10 and the second micro pump 20 are arranged in fluid series connection and have the same fluid pumping direction.

[0065] More specifically, the sensor device 100 includes two micropumps 10, 20, for example, two microfluidic or peristaltic pumps, each having a normally closed safety valve 11, 21, wherein the fluid sensor 30 (for example, a gas or liquid sensor) is arranged in a sensor chamber 31, which is fluidically coupled between the two micropumps 10, 20 and is separated so as to be sealed relative to the environment E. Since the two micropumps 10, 20 are arranged in fluid series connection and have the same fluid pumping direction, both negative and positive fluid pressures can be generated in the enclosed sensor chamber 31.

[0066] According to an embodiment, the sensor device 100 is configured to sense the presence, amount or concentration of a target fluid FT or a target fluid component in a fluid F or medium (e.g. a carrier fluid or an ambient medium) in the sensor chamber 31. In the present context, the term fluid may relate to a liquid or a gas. In case the fluid or medium in the sensor chamber 31 relates to ambient air, the target fluid may relate to a target gas or a target gas component present in the ambient air (= surrounding atmosphere). The present concept is equally applicable to sensing a target liquid or a target liquid component in an ambient medium. In this context, a gas or a liquid is generally referred to as a fluid.

[0067] According to an embodiment, the first micropump 10 includes a pump inlet 13, a pump chamber 14, and a pump outlet 12, wherein the first micropump 10 is configured to pump the fluid (e.g., ambient air) from the pump inlet 13 through the pump chamber 14 to the pump outlet 12. According to an embodiment, the second micropump 20 includes a pump inlet 23, a pump chamber 24, and a pump outlet 22, wherein the second micropump 20 is configured to pump the fluid from the pump inlet 23 through the pump chamber 24 to the pump outlet 22. As shown, the sensor chamber 31 is fluidly coupled between the pump outlet 12 of the first micropump 10 and the pump inlet 23 of the second micropump 20 and is separated so as to be sealed (e.g., airtight or encapsulated) from the environment.

[0068] As shown in the drawings, the pump inlet 13 of the first micropump 10 is fluidically coupled to or forms the fluid inlet 40 of the sensor device 100, wherein the pump outlet 22 of the second micropump 20 is fluidically coupled to or forms the fluid outlet 40 of the sensor device 100. The first micropump 10 and the second micropump 20 can be formed as micromembrane pumps, each of which includes a passive check valve such as the safety valve 11, 21. The micromembrane pump 20 may include a pump membrane 15, 25, wherein a piezoelectric ceramic element 16, 26 may be attached to the pump membrane 15, 25, so that by actuating the piezoelectric ceramic element 16, 26, the volume of the pump chamber 14, 24 of the diaphragm pump 10, 20 can be changed. For this purpose, a suitable method (e.g., device 50, see below) is provided for applying a voltage to the piezoelectric ceramic element 16, 26 bonded to the pump diaphragm 15, 25 and for causing the piezoelectric ceramic element 16, 26 to change from such as Figure 1 The position shown is deflected into a position in which the volume of the pump chamber 14 , 24 is reduced.

[0069] According to an embodiment, the NC safety valve 11 of the first micropump 10 includes a valve seat 11-1 and a valve cover 11-2 and is arranged at the pump outlet 12 of the first micropump 10, and wherein the NC safety valve 21 of the second micropump 20 includes a valve seat 21-1 and a valve cover 21-2 and is arranged at the pump outlet 22 of the second micropump 20.

[0070] According to an embodiment, the first micropump 10 and the second micropump 20, the sensor 30 and optionally the processing device 50 (see below) can be integrated into a semiconductor substrate, such as a silicon substrate. According to an embodiment, the sensor element 32 is sensitive to the chemical or physical state of the fluid in the fluid chamber 31. The integration of the sensor device 100 (or at least a large part thereof) in the semiconductor substrate 60 allows to provide a relatively small dead volume of the micropumps 10, 20 in the range of about a few μl (microliters) (for example, in the range between 1 μl and 10 μl). Based on the relatively small dead volume of the micropumps 10, 20, the measuring time and the measuring accuracy of the fluid sensor can be increased (improved), wherein, in addition, the calibration of the fluid sensor 30 can be significantly improved. In addition, if sharp corners or ridges in the fluid channels 12-1, 23-1 of the fluid sensor 30 can be (at least partially) avoided, the dispersion of the fluid or fluid particles F flowing through the fluid sensor 30 can be avoided (minimized) or at least reduced.

[0071] Thus, the sensor device 100 comprises a sealed or encapsulated sensor chamber 31. The encapsulated sensor chamber 31 provides a defined sensor volume during measurement, which is enclosed with respect to the surrounding atmosphere outside the gas sensor. Thus, if the micropump 10, 20 is switched off, disturbing convection can be avoided, which leads to good conditions for gas measurement.

[0072] Based on this implementation of the sensor device 100, a compact solution for the gas sensor can be achieved, wherein the sensor device 100 can achieve negative pressure or positive pressure in the sensor chamber 31 in a component that is as small and flat as possible, and the sensor device 100 can also be easily integrated into a mobile device.

[0073] In the following, Figure 2A-2E Different operating modes and states of the sensor device 100 according to further embodiments are shown. According to embodiments, the sensor device 100 may be operated in different operating modes.

[0074] Figure 2A The sensor device 100 is shown in an idle or non-operating state (see also Figure 1 ).

[0075] Figure 2B The sensor device 100 is shown in a first operating mode, such as a vacuum mode. In the first operating mode (vacuum mode) of the sensor device 100, the first micropump 10 is in an off state, such as a closed state or deactivated, and the second micropump 20 is in an on state, such as an open state, activated or energized to provide a defined negative fluid pressure in the sensor chamber 31, such as Figure 2B Shown as an example.

[0076] The second micro pump may be optimized to provide a high negative pressure relative to atmospheric pressure (ambient pressure).If a high negative pressure is achieved, the sensor device may be calibrated very effectively, for example in combination with heating of the fluid sensor element 32 (eg, gas sensing membrane).

[0077] According to current technology, the micropumps 10, 20 can achieve, for example, a negative pressure between 40 kPa (kilopascals) and 60 kPa, wherein the design of the micropumps 10, 20 is adapted, and the negative pressure of a single micropump 10, 20 can be increased to about 70 kPa to 80 kPa or even 100 kPa (negative pressure). Thus, the first micropump 10 and the second micropump 20 can be optimized to provide a high negative pressure. The optional pressure sensor 33 can, for example, measure the pressure in the sensor chamber 31 as a reference value for the sensor reading and as feedback for setting a certain pressure in the sensor chamber 31 (for example, as a set point).

[0078] Figure 2C 1 shows the sensor device 100 in a second operating mode (e.g., overpressure mode). In the second operating mode (overpressure mode), the first micropump 10 is in an on state and the second micropump 20 is in an off state to provide a defined positive fluid pressure in the sensor chamber 31, such as Figure 2C Shown as an example.

[0079] The first micropump 10 can be optimized to provide a high positive pressure, for example, the currently illustrated micropumps 10, 20 can achieve an air back pressure of up to 100 kPa. An optional pressure sensor 33 can, for example, measure the pressure in the sensor chamber 31 as a reference value for the sensor reading and as feedback for setting a certain pressure in the sensor chamber 31. In addition, a high or increased pressure in the sensor chamber 31 can improve the binding process of the target fluid FT with the sensor element 32 in the sensor chamber 31. The integration of a pressure sensor 33 (e.g., a piezoelectric element) in the sensor chamber 31 allows the pressure in the sensor chamber 31 to be controlled and enables very accurate measurements.

[0080] Figure 2D The sensor device 100 is shown in an alternative second operating mode. According to further embodiments, the second operating mode may include a first partial operating mode (eg Figure 2C ) and the subsequent second part of the operation mode (as shown Figure 2D ), wherein in the first partial operation mode, the first micro pump 10 is in an on state and the second micro pump 20 is in an off state to provide a defined positive fluid pressure in the sensor chamber 31. Figure 2DIn the (immediately) subsequent second partial operation mode, the first micropump 10 is in (switched to) an off state and the second micropump 20 is in (kept to) an off state to provide a defined amount of fluid in the sensor chamber 31 (e.g., in the fluid path and the sensor chamber), i.e., a defined fluid volume or a defined measurement volume. Thus, the sensor element 32 can interact with a defined amount of “loaded” fluid F input into the sensor chamber 31.

[0081] Figure 2E The sensor device 100 is shown in a third operating mode, such as a purge mode. In the third operating mode (purge mode), the first micropump 10 is in an on state and the second micropump 20 is in an on state to provide a defined fluid flow rate (e.g., having a defined fluid throughput) through the sensor chamber 31, such as Figure 2E Shown by way of example.

[0082] The purging mode of the sensor device may provide or even improve effective calibration, for example, again in combination with heating of the fluid sensor element.

[0083] According to an embodiment, an energy efficient purge mode may be achieved by 180° phase shifted actuation of the micropumps 10 , 20 , which results in an improved flow rate of the fluid through the sensor chamber 31 .

[0084] According to an embodiment, the sensor device 100 may further include a pressure sensor 33 disposed in the sensor chamber 31 or fluidically coupled to the sensor chamber 31 to measure the fluid pressure in the sensor chamber 31 .

[0085] In general, if the pressure at the sensor element 32 (e.g., the gas sensor layer) can be adjusted, this feature can be used to obtain more specific sensor feedback. More specifically, gas measurement at a certain pressure level results in specific binding of gas molecules at the sensor element 32, thereby enabling specific gas measurement. Thus, providing the pressure sensor 33 allows the pressure at the sensor element 32 (gas sensor membrane) to be changed, so that a pressure-dependent fluid (gas) absorption curve or profile can be detected.

[0086] According to an embodiment, the first micropump 10 may include multiple micropump elements in a cascade arrangement (e.g., fluidly connected in series) to provide an increased positive fluid pressure in the sensor chamber, and / or fluidly connected in parallel to provide an increased fluid throughput through the sensor chamber 31.

[0087] According to an embodiment, the second micropump 20 may include multiple micropump elements in a cascade arrangement (e.g., fluidly connected in series) to provide an increased negative fluid pressure in the sensor chamber, and / or fluidly connected in parallel to provide an increased fluid throughput through the sensor chamber 31.

[0088] Thus, cascading the pumps 10 , 20 may increase the negative or positive pressure. However, cascading the pumps 10 , 20 may require adapter caps for the pumps 10 , 20 .

[0089] According to an embodiment, the sensor device 100 may further include a heating element 34, which is arranged in the sensor chamber 31 or is thermally coupled to the sensor chamber 31 to heat the fluid or adjust the temperature of the fluid in the sensor chamber 31, and / or heat the sensor element 32 of the sensor 30. Thus, the heating element 34 may provide different measurement temperatures in the sensor chamber 31. In addition, the heating element 34 may provide or at least support a “reset” (regeneration or recovery) of the sensor element 32 (e.g., active sensor area).

[0090] According to an embodiment, the sensor device 100 may further include a temperature sensor 35 , which is arranged in the sensor chamber 31 or thermally coupled to the sensor chamber 31 to measure the temperature in the sensor chamber 31 .

[0091] As indicated above, pressure dependent fluid (gas) absorption curves may be detected, wherein the provision of the temperature sensor 35 and / or heater 34 may provide temperature regulation of the fluid F in the sensor chamber 31. Based on the controlled temperature and pressure in the sensor chamber 31, temperature / pressure matrix measurements enable detection of specific molecules from the matrix, e.g. by pattern recognition.

[0092] Thus, the proposed sensor device 100 may combine the technical effects of setting and controlling the pressure and temperature of the fluid, and / or the technical effects of the sensor element 32 and the sensor chamber 31 of the sensor 30 .

[0093] More specifically, in order to explain the sensor output signal S OUT For example, if the pressure sensor 33, the heater 34 and optionally also the temperature sensor 35 are implemented in the sensor chamber 31, different states (eg temperature and / or pressure states) in the sensor chamber 31 can be set.

[0094] In case the sensor device 100 is implemented as a VOC gas sensor (VOC = Volatile Organic Compounds), it is challenging to identify a specific fluid or fluid compound (e.g., gas or gas component) of a plurality of different organic compounds. This is especially true if the sensor device 100 is intended to measure toxic and / or hazardous gases (e.g., formaldehyde or benzene).

[0095] Based on the inventive sensor concept, the sensor output signal S in different operating states that can be set in the sensor chamber 31 can be explained. OUT , so that the proposed concept can extend the parameter space (parameterspace or parameter room): only from the temperature T (with the heater 34) to the parameter "pressure p", which can be adjusted by the treatment device 50; and also to the flow rate Q, which can be adjusted by the purge mode (see for example Figure 2E ) is generated by the micro pumps 10, 20 during the period.

[0096] In the following, some exemplary implementations of the parameter space for interpreting the sensor output signal are described:

[0097] -Linear domain:

[0098] οThe temperature change between p1...p2 at a given temperature T.

[0099] -Matrix (PxT):

[0100] o Pressure changes between p1 ... p2, temperature changes between T1, ... T2. Sensor feedback of the entire matrix can be used to identify a specific gas, so that the specificity of the gas sensor 30 can be improved.

[0101] -Matrix (QxT):

[0102] oFlow rate changes between Q1, ...Q2, temperature changes between T1, ...T2, and sensor feedback of the entire matrix can be used to identify a specific gas, so that the specificity of the fluid sensor 30 can be improved.

[0103] According to an embodiment, machine learning and AI algorithms (AI = Artificial Intelligence) may be used to support the interpretation of this measurement matrix.

[0104] According to an embodiment, the sensor device 100 may include a processing device 50, such as a controller or an ASIC, configured to use a first control signal S 10 To control the operation mode of the first micro pump 10, the second control signal S 20to control the operation mode of the second micro pump 20 and read the sensor output signal S of the sensor 30 in the set operation mode. OUT Thus, the processing device 50 is configured to control the operation mode of the heating element 34 and to read the pressure sensor 33 and / or the temperature sensor 35 coupled to the sensor chamber 31 of the sensor 30 .

[0105] According to an embodiment, the processing device 50 is configured to: (1) control the operating mode of the first micropump 10 and the second micropump 20 to adjust the fluid pressure of the sensor chamber 31 and / or the fluid throughput or fluid flow rate through the sensor chamber 31; (2) control the heating element 34 to adjust the temperature of the fluid in the sensor chamber 31 and / or the different or varying temperatures of the sensor element; and (3) read out the sensor output signal at different temperatures.

[0106] According to an embodiment, the processing device 50 can be configured to determine a sensor matrix including information about: (1) the read sensor output signals; (2) the operating modes of the first micropump 10 and the second micropump 20, such as different operating modes; and (3) different temperatures in the sensor chamber 31.

[0107] According to an embodiment, the processing device 50 may also be configured to determine a sensor matrix comprising information about: (4) the measured pressure in the sensor chamber 31 .

[0108] According to an embodiment, the processing device 50 may also be configured to determine a sensor matrix comprising information about: (5) a defined fluid flow rate, for example through the sensor chamber 31 , for example having a defined fluid throughput.

[0109] In summary, the processing device can set different states in the sensor chamber, for example, one of different operating modes, temperatures and / or fluid pressures in the sensor chamber, and can interpret the sensor signal based on the set state in the sensor chamber. This approach enables the expansion of the parameter room (parameter space): from temperature T (with a heater) to parameter pressure P (which can be adjusted) and also to flow rate Q (generated by the micro pump during the set operating mode (e.g., the purge mode, the vacuum mode or the overpressure mode)).

[0110] Thus, the proposed sensor concept enables numerous possibilities to improve the interpretation of the sensor signal with regard to sensitivity and specificity.

[0111] According to an embodiment, the processing device 50 may also be configured to provide a rectangular or sinusoidal actuation signal S to the first micropump 10 and the second micropump 20. 10 , S 20 of the adjusted actuation.

[0112] According to an embodiment, the processing device 50 can also be configured to determine the presence, amount or concentration of the target fluid in the fluid in the sensor chamber 31 based on the obtained pressure oscillation curve of the fluid in the sensor chamber 31 (e.g., the fluid having the target fluid).

[0113] Furthermore, the proposed sensor concept also allows to use the dynamic properties of the sensor device to interpret the sensor signal with regard to sensitivity and specificity.

[0114] More specifically, different time constants for pressurization (and vacuum build-up) in the sensor chamber can enhance the effectiveness of specific gas measurements. This can be achieved by slowing down or speeding up the pumping to fill / empty the sensor chamber.

[0115] The same is true for dynamic pressure buildup / vacuum establishment (pressure cycling). Different behavior for changing gas concentrations is expected. However, adjusted actuation (e.g., rectangular actuation) may cause oscillations of membranes (even gas sensing membranes), safety valve membranes, or / and molecules in the system and may adversely affect or impact the sensing process.

[0116] According to an embodiment, the processing device 50 may also be configured to provide a rectangular or sinusoidal actuation signal S to the first micro pump 10 and / or the second micro pump 20, respectively. 10 , S 20 The adjusted or set actuation.

[0117] According to an embodiment, the processing device 50 may be configured to provide rectangular actuation (only) when a high volume flow Q is required to "clean" the sensor 30. The processing device 50 may then be configured to switch to harmonic actuation (e.g. sinusoidal actuation) for unicast equalization, or may be configured to stop pumping operation during sensing operation.

[0118] According to an embodiment, the processing device 50 may be configured to retrieve or read out a "pressure oscillation curve" of the fluid or gas F, wherein the pressure oscillation curve is specific to some fluid or gas molecules. This may result in different binding behaviors of the target fluid and thus in changes in the sensor response (sensor output signal), which may be interpreted by the processing device 50 to retrieve the kind (type), amount and / or concentration of the target fluid FT in the sensor chamber 31. Furthermore, AI analysis (AI=Artificial Intelligence) and pattern recognition may provide a very specific fluid or gas sensitivity of the sensor 30.

[0119] According to the proposed fluid sensing concept, the response of the target fluid F to the target fluid F can be observed and interpreted. T Dynamic influence of the chemical binding process with the sensor element 32 (eg sensor membrane). In this connection, however, it should be noted that dynamic influences may be difficult to control because they may easily go out of their operating range due to external influences (such as temperature changes, pressure changes, etc.).

[0120] According to an embodiment, the sensor element 32 senses the target fluid F in the fluid F in the sensor chamber 31. T According to an embodiment, the sensor element 32 is sensitive to the presence, amount and / or concentration of a target gas in the gas in the sensor chamber 31, wherein the target gas includes VOC (VOC=volatile organic compounds), CO X (e.g., CO or CO2), O X (e.g., O2 or O3) or NO X (e.g., NO or NO2) sensitive.

[0121] According to an embodiment, the sensor element 32 is based on a metal oxide (eg MO X or metal oxide semiconductor). VOC gases may include formaldehyde (CH2O), benzene, hydrogen sulfide (H2S), MTBE, methylene chloride, perchloroethylene, chlorofluorocarbons and chlorocarbons, tetrachloroethylene, etc. However, this list of VOC gases to be detected is not considered to be exhaustive.

[0122] According to an embodiment, the sensor element 32 is an electrochemical sensor with a liquid or solid electrolyte material.According to an embodiment, the sensor element 32 is sensitive to the concentration of particulate matter in the fluid (eg ambient gas or ambient air) in the sensor chamber 31 .

[0123] According to an embodiment, the safety valve 11, 21 and the valve cover 11-2, 21-2 and optionally the valve seat 11-11, 21-1 may be integrated in silicon to provide a silicon micropump 10, 20, or may be formed of metal to provide a metal micropump 10, 20. Alternatively, the valve cover 11-2, 21-2 may be attached as a polymer diaphragm and clamped between the corresponding micropump 10, 20 and the carrier (substrate) 60.

[0124] According to an embodiment, the safety valve 11, 21 is integrated into the corresponding micropump 10, 20, which can be glued to the carrier 60 and / or manifold 60'. In case of the gluing process, low degassing is recommended to maintain the operating characteristics of the micropump 10, 20.

[0125] In case of implementing polymer safety valve diaphragms 11-2, 21-2, the micro pumps 10, 20 can be clamped to the manifold. In addition, it is recommended to use a low degassing process for the polymer material.

[0126] The sensor device 100 and / or the respective manifold 60 ′ of the sensor 30 , and in particular the fluid channels and the sensor chamber 31 of the sensor 30 , may be realized by means of metal foils, which may be bonded together by means of a laser welding process.

[0127] According to a further embodiment, it is possible to implement the direct integration of the manifold 60' of the sensor device 100 into a PCB (PCB = printed circuit board), wherein corresponding techniques for preparing buried vias can be applied to build corresponding channels and chambers within the PCB. In the case of a PCB implementation, the only materials in contact with the test fluid are semiconductor materials (e.g. silicon) and the PCB material (e.g. FR4). If necessary, the PCB material can be covered with metal (e.g. gold) to avoid particle accumulation. This approach enables the use of MEMS technology (MEMS = micro-electromechanical systems) and manufacturing processes in combination with MEMS sensors. The metal-covered surface of the manifold 60' provides low outgassing during the manufacture and use of the sensor.

[0128] According to another embodiment, the manifold 60 ′ may be realized as a glass material, which also achieves low fluid (gas) particle accumulation.

[0129] As described above, the pressure sensor 33 may be arranged in the sensor chamber 31 or integrated in the sensor chamber 31, or may be fluidically coupled to the sensor chamber 31 to measure the fluid pressure in the sensor chamber 31. Providing the controlled pressure P in the sensor chamber 31 enables conducting very accurate measurement results, wherein the pressure sensor 33 may be implemented by a piezoresistive pressure sensor, a capacitive pressure sensor, a piezoelectric element, etc.

[0130] Furthermore, many (currently available) pressure sensors 33 have also integrated a temperature sensor 35, which can be used to measure the temperature in the sensor chamber 31 and control the temperature in the sensor chamber 31 based on the heating operation of the heating element 34. The heating element 34 can be integrated in the sensor chamber 31, or can be thermally coupled to the sensor chamber 31 to heat the fluid F in the sensor chamber 31 and / or the sensor element 32 of the sensor 30.

[0131] In the following, some general integration steps for producing the sensor device are now described exemplarily.

[0132] According to the first step, both micropumps 10, 20 can be formed from or in the same wafer and can be sawn into a single (one) piece. In step 2, the flow channels 12-1, 23-1 and the gas sensor chamber 31 can be implemented in a single chip together with both micropumps 10, 20 by etching processes, wherein, based on semiconductor processing steps, a dead volume of the sensor 30 below 1 μl or below 10 μl can be achieved. In a third step, the fluid sensor technology (e.g., the gas sensor) is integrated into the silicon chip / substrate 60, wherein a dead volume below 0.5 μl can be achieved.

[0133] According to an embodiment, a microprocessor ASIC (ASIC=Application Specific Integrated Circuit) can be combined with a sensor ASIC into only one chip (sawn or single semiconductor substrate), which allows direct integration into the manifold 60 ′ with the lowest possible energy consumption.

[0134] According to an embodiment, the sensor element 32 in the sensor chamber 31 may also be sensitive to the concentration of particulate matter in the fluid F. In this connection, reference is made to the fact that a fluid sensor or a gas sensor 30 may have cross contamination due to particles sensed by a correspondingly equipped sensor that may be used to sense particulate matter.

[0135] The output signal S of the sensor element 32 obtained in the overpressure mode in the sensor chamber is 1.3 V due to adsorption, i.e. the adhesion of atoms, ions or molecules from the fluid (gas, liquid or dissolved solid) to the surface as the surface of the sensor element 32, which can enhance the chemical reaction. OUT May be suitable for target fluid sensing, ie sensing the presence and / or concentration of said target fluid FT.

[0136] According to an embodiment, the sensor device can also be used to implement a micro pump desiccant or a desiccator. A desiccant is a seed shell containing a desiccant that is used to preserve moisture sensitive items for other uses. A common use of a desiccant is to protect hygroscopic or water reactive chemicals from moisture.

[0137] According to further embodiments, the sensor device comprises at least two micropumps 10, 20, which can also support and / or provide proper recovery (resetting or regeneration) of the sensor element (e.g. active sensor area) by means of the purge mode as described above.

[0138] Figure 3 A schematic block diagram of a method 200 for sensing the amount or concentration of a target fluid in a medium using the sensor device according to an embodiment is shown.

[0139] According to an embodiment, the method 300 for sensing the amount or concentration of a target fluid in a medium (e.g., a carrier fluid or an ambient medium) using the sensor device 100 as described above includes the following steps: adjusting the operating mode of the first micropump 10 and the second micropump 20, for example with the aid of the processing device 50; and reading out the sensor output signal of the sensor 30 in the adjusted operating mode, for example with the aid of the processing device 50.

[0140] According to an embodiment, the method 300 may further include the following steps: adjusting or changing (setting) 330 the temperature of the fluid in the sensor chamber and / or the temperature of the sensor element 32 of the sensor 30, for example by means of a heating element 34 arranged in the sensor chamber or thermally coupled to the sensor chamber, so as to provide different measurement temperatures in the sensor chamber 31; measuring 340 the temperature in the sensor chamber 31, for example by means of a temperature sensor 35 in the sensor chamber or thermally coupled to the sensor chamber 31; and reading 350 the sensor output signal at different temperatures, for example by means of the processing device 50.

[0141] According to an embodiment, the method 300 may further include the following steps: adjusting 360 the fluid pressure in the sensor chamber 31 and / or the fluid throughput (e.g., the fluid flow rate) through the sensor chamber 31 to provide different fluid pressures in the sensor chamber 31 and / or different fluid throughputs (e.g., the fluid flow rates) through the sensor chamber 31; measuring 370 the fluid pressure in the sensor chamber and / or the fluid throughput (e.g., the fluid flow rate) through the sensor chamber 31, for example, by means of a pressure sensor 33 arranged in the sensor chamber or fluidically coupled to the sensor chamber 31; and reading out 380 the sensor output signal at different fluid pressures in the sensor chamber 31 and / or the fluid throughputs through the sensor chamber 31, for example, by means of the processing device 50.

[0142] According to an embodiment, the method 300 may further include the following steps: for example, determining 390 by means of the processing device 50 a sensor output signal matrix including information (1) related to the read sensor output signal and information (2) related to the operating modes (e.g., different operating modes) of the first micropump 10 and the second micropump 20.

[0143] According to an embodiment, the method 300 may further comprise the step of determining 400 , for example by means of the processing device 50 , the sensor matrix comprising information ( 3 ) about different temperatures in the sensor chamber 31 .

[0144] According to an embodiment, the method 300 may further comprise the step of determining 410 , for example by means of the processing device 50 , the sensor matrix comprising information ( 4 ) regarding the measured pressure in the sensor chamber 31 .

[0145] According to an embodiment, the method 300 may further comprise the following steps: determining 430 the sensor matrix comprising information (5) relating to a defined fluid flow (e.g., having a defined fluid throughput) through the sensor chamber 31, e.g. by means of the processing device 50.

[0146] According to an embodiment, the method 300 may further comprise the following steps: determining 430 the presence, amount or concentration of the target fluid in the fluid in the sensor chamber 31 based on the obtained sensor output signal matrix, for example with the aid of the processing device, wherein the sensor matrix provides a plurality of parameter values, such as temperature and / or pressure and / or fluid flow, for each sensor output value.

[0147] When using the proposed sensor device 100 as a VOC sensor, different VOCs and their concentrations in the fluid medium (e.g., carrier gas) in the sensor chamber 31 can be distinguished, since the determined sensor output signal matrix provides multiple parameter values ​​for each sensor output value, such as temperature and / or pressure and / or fluid flow. Thus, based on the sensor output signal matrix and the multiple parameter values ​​for each sensor output value (such as temperature and / or pressure and / or fluid flow), different VOCs and their concentrations can be determined by evaluating different parameter values ​​and distributions of sensor output values ​​and / or by characteristically associating the sensor output values ​​with different parameter values. Thus, characteristic sensor signal measurement fields for different VOCs can be derived based on the sensor output signal with the associated measurement parameters (e.g., temperature and / or pressure and / or fluid flow in the fluid chamber).

[0148] According to further embodiments, the micropumps 10, 20 may be manufactured to include a very low dead volume, so that the measurement volume in the sensor chamber 31 and between the two micropumps 10, 20 may be accurately determined. Thus, the proposed sensor device 100 may be implemented with a target gas consuming or absorbing sensor element 32. Based on the gas sensing concept, the micropumps 10, 20 may deliver a defined fluid volume to the sensor chamber 31, wherein the target gas (e.g., all target gas molecules) may be consumed, absorbed or bound to the sensor element 32. Based on the defined measurement volume and the resulting sensor output signal, e.g., triggered by all or substantially all target gas molecules in the sensor chamber 31, the precise target gas concentration in the sensor chamber 31 having a defined measurement volume may be determined.

[0149] Additional embodiments and aspects are described that may be used alone or in combination with the features and functionality described herein.

[0150] According to an embodiment, the sensor device 100 includes a first micro pump 10 having a normally closed (NC) safety valve 11, a second micro pump 20 having a normally closed (NC) safety valve 21, and a sensor 30 having a sensor chamber 31, wherein the sensor chamber 31 has a sensor element 32 located in the sensor chamber 31, wherein the sensor 30 is configured to provide a sensor output signal S based on the state of the fluid F in the sensor chamber 31. OUT, wherein the sensor chamber 31 of the sensor 30 is fluidly coupled between the first micropump 10 and the second micropump 20, and wherein the first micropump 10 and the second micropump 20 are configured to provide a defined operating mode of the sensor device 100 based on the corresponding starting states of the first micropump 10 and the second micropump 20 to provide: (1) a defined negative fluid pressure in the sensor chamber 31; (2) a defined positive fluid pressure in the sensor chamber 31; or (3) a defined fluid flow through the sensor chamber 31.

[0151] According to an embodiment, the first micro pump 10 and the second micro pump 20 are arranged in fluid series connection and have the same fluid pumping direction.

[0152] According to an embodiment, in a first operating mode, the first micropump 10 is in an off state and the second micropump 20 is in an on state to provide a defined negative fluid pressure in the sensor chamber 31, wherein in a second operating mode, the first micropump 10 is in an on state and the second micropump 20 is in an off state to provide a defined positive fluid pressure in the sensor chamber 31, and / or wherein in a third operating mode, the first micropump 10 is in an on state and the second micropump 20 is in an on state to provide a defined fluid flow through the sensor chamber 31.

[0153] According to an embodiment, the second operating mode includes a first partial operating mode and a subsequent second partial operating mode, wherein in the first partial operating mode, the first micropump 10 is in an on state and the second micropump 20 is in an off state to provide a defined positive fluid pressure in the sensor chamber 31, and wherein in the subsequent second partial operating mode, the first micropump 10 is in an off state and the second micropump 20 is in an off state to provide a defined fluid amount in the sensor chamber 31.

[0154] According to an embodiment, the first micropump 10 includes a pump inlet 13, a pump chamber 14 and a pump outlet 12, wherein the first micropump 10 is configured to pump the fluid F from the pump inlet 13 to the pump outlet 12 through the pump chamber 31, wherein the second micropump 20 includes a pump inlet 23, a pump chamber 24 and a pump outlet 22, wherein the second micropump 20 is configured to pump the fluid F from the pump inlet 23 to the pump outlet 22 through the pump chamber 24, and wherein the sensor chamber 31 is fluidically coupled between the pump outlet 12 of the first micropump 10 and the pump inlet 23 of the second micropump 20 and are separated so as to be sealed relative to the environment E.

[0155] According to an embodiment, the NC safety valve 11 of the first micropump 10 includes a valve seat 11-1 and a valve cover 11-2, and the NC safety valve 11 is arranged at the pump outlet 12 of the first micropump 10, and wherein the NC safety valve 21 of the second micropump 20 includes a valve seat 21-1 and a valve cover 21-2, and the NC safety valve 21 is arranged at the pump outlet 22 of the second micropump 20.

[0156] According to an embodiment, the sensor device 100 further includes a pressure sensor 33 , which is located in the sensor chamber 31 or is fluidically coupled to the sensor chamber 31 to measure the fluid pressure in the sensor chamber 31 .

[0157] According to an embodiment, the sensor device 100 further includes a heating element 34 located in the sensor chamber 31 or thermally coupled to the sensor chamber 31 to heat the fluid F in the sensor chamber 31 of the sensor 30 and / or the sensor element 32 .

[0158] According to an embodiment, the sensor device 100 further includes a temperature sensor 35 , which is arranged in the sensor chamber 31 or thermally coupled to the sensor chamber 31 to measure the temperature in the sensor chamber 31 .

[0159] According to an embodiment, the sensor device 100 further comprises a processing device 50 configured to control the operation mode of the first micropump 10 and the second micropump 20 and to read out the sensor output signal SoUT of the sensor 30 in the adjusted operation mode.

[0160] According to an embodiment, the processing device 50 is configured to control an operation mode of the heating element 34 and to read a pressure sensor 33 and / or a temperature sensor 35 coupled to the sensor chamber 31 of the sensor.

[0161] According to an embodiment, the first micropump 10 comprises a plurality of micropump elements arranged in cascade, and / or wherein the second micropump 20 comprises a plurality of micropump elements arranged in cascade.

[0162] According to an embodiment, the processing device 50 is configured to: (1) control the operating mode of the first micropump 10 and the second micropump 20 to adjust the fluid pressure in the sensor chamber 31 and / or the fluid flow through the sensor chamber 31; (2) control the heating element 34 to adjust different temperatures in the sensor chamber 31; and (3) read out the sensor output signal at different temperatures.

[0163] According to an embodiment, the processing device 50 may be configured to determine a value including the value corresponding to the read sensor output signal S OUT The sensor matrix includes information (1) about the temperature of the sensor chamber 31, information (2) about the operation modes of the first micropump 10 and the second micropump 20, and information (3) about the different temperatures in the sensor chamber 31.

[0164] According to an embodiment, the processing device 50 is further configured to determine a sensor matrix comprising information (4) related to the measured pressure in the sensor chamber 31 .

[0165] According to an embodiment, the processing device 50 is further configured to determine a sensor matrix comprising information ( 5 ) relating to a defined fluid flow through the sensor chamber 31 .

[0166] According to an embodiment, the processing device 50 is configured to provide a regulated actuation with a rectangular or sinusoidal actuation signal S10 , S20 to the first and second micropumps.

[0167] According to an embodiment, the processing device 50 is further configured to determine the presence, amount or concentration of a target fluid FT in the fluid in the sensor chamber 31 based on the resulting pressure oscillation curve of the fluid F in the sensor chamber 31 .

[0168] According to an embodiment, the first micro pump 10 and the second micro pump 20 , the sensor 30 and the processing device 50 are integrated into a semiconductor substrate.

[0169] According to an embodiment, the sensor element 32 is sensitive to a chemical or physical state of the fluid F in the sensor chamber 31 .

[0170] According to an embodiment, the sensor element 32 is sensitive to the concentration of the target fluid FT in the fluid F in the sensor chamber 31 .

[0171] According to an embodiment, the sensor element 32 senses the target gas F in the gas in the sensor chamber 31. T The target gas comprises volatile organic compounds (VOC), CO X , O X or NO X .

[0172] According to an embodiment, the sensor element 32 is a metal oxide based VOC sensor.

[0173] According to an embodiment, the sensor element 32 is an electrochemical sensor having a liquid or solid electrolyte material.

[0174] According to an embodiment, the sensor element 32 is sensitive to the concentration of particulate matter in the fluid F in the sensor chamber 31 .

[0175] According to an embodiment, a method 300 for sensing the amount or concentration of a target fluid FT in a medium F using the sensor device 100 described above comprises the following steps: adjusting 310 the operation mode of the first micro pump 10 and the second micro pump 20; and reading 320 the sensor output signal S of the sensor 30 in the set operation mode. OUT .

[0176] According to an embodiment, the method 300 further comprises the following steps: setting 330 the temperature of the fluid F in the sensor chamber 31 and / or the sensor 32 element of the sensor 30 to provide different measurement temperatures in the sensor chamber 31; measuring 340 the temperature in the sensor chamber 31; and reading 350 the sensor output signal S at different temperatures. OUT .

[0177] According to an embodiment, the method 300 further comprises the following steps: adjusting 360 the fluid pressure in the sensor chamber 31 and / or the fluid throughput through the sensor chamber 31 to provide different fluid pressures in the sensor chamber 31 and / or different fluid throughputs through the sensor chamber 31; measuring 370 the fluid pressure in the sensor chamber 31 and / or the fluid throughput through the sensor chamber 31; and reading 380 the sensor output signal S at different fluid pressures in the sensor chamber 31 and / or the fluid throughputs through the sensor chamber 31. OUT .

[0178] According to an embodiment, the method 300 further comprises the step of determining 390 a sensor output signal matrix comprising information (1) about the read sensor output signals and information (2) about the set operating mode of the first micropump 10 and the second micropump 20 .

[0179] According to an embodiment, the method 300 further comprises the step of determining 400 the sensor matrix comprising information (3) relating to different temperatures in the sensor chamber 31 .

[0180] According to an embodiment, the method 300 further comprises the step of determining 410 the sensor matrix comprising information (4) regarding the measured pressure in the sensor chamber 31 .

[0181] According to an embodiment, the method 300 further comprises the step of determining 420 the sensor matrix comprising information ( 5 ) related to a defined fluid flow through the sensor chamber 31 .

[0182] According to an embodiment, the method further comprises the step of determining 430 the presence, amount or concentration of a target fluid FT in the fluid F in the sensor chamber 31 based on the obtained sensor output signal matrix.

[0183] Although some aspects have been described as features in the context of an apparatus, it is clear that such a description may also be viewed as a description of corresponding features of a method. Although some aspects have been described as features in the context of an apparatus, it is clear that such a description may also be viewed as a description of corresponding features related to the functionality of the apparatus.

[0184] Depending on certain implementation requirements, embodiments of the processing device 50 may be implemented in hardware, in software or at least partially in hardware or at least partially in software. The implementation may be performed using a digital storage medium, such as a floppy disk, DVD, Blu-ray, CD, ROM, PROM, EPROM, EEPROM or flash memory, having electronically readable control signals stored thereon, which control signals cooperate (or can cooperate with) a programmable computer system so that the corresponding method is performed. Thus, the digital storage medium may be computer readable. Some embodiments comprise a data carrier having electronically readable control signals, which control signals can cooperate with a programmable computer system so that one of the methods described herein is performed.

[0185] Typically, embodiments of the processing device may be implemented as a computer program product having a program code, which is operable to perform one of the methods described herein when the computer program product is run on a computer. The program code may, for example, be stored on a machine-readable carrier. Other embodiments include the computer program for performing one of the methods described herein and stored on a machine-readable carrier. Thus, in other words, an embodiment of the method is a computer program having a program code for performing one of the methods described herein when the computer program is run on a computer.

[0186] Therefore, a further embodiment of the method is a data carrier (or digital storage medium, or computer readable medium) comprising the computer program recorded thereon for performing one of the methods described herein. The data carrier, the digital storage medium or the recorded medium is typically tangible and / or non-transitory. Further embodiments include a processing device (e.g., a computer) or a programmable logic device configured or adapted to perform one of the methods described herein. Further embodiments include a computer having installed thereon the computer program for performing one of the methods described herein.

[0187] In some embodiments, a programmable logic device (e.g., a field programmable gate array) can be used to perform some or all of the functions of the method described herein. In some embodiments, a field programmable gate array can be used in conjunction with a microprocessor to perform one of the methods described herein. Typically, the method is preferably performed by any hardware device.

[0188] The apparatus described herein can be implemented using a hardware device or using a computer or using a combination of a hardware device and a computer. The method described herein can be performed using a hardware device or using a computer or using a combination of a hardware device and a computer.

[0189] It can be seen in the previous specific embodiments that, in order to simplify the present disclosure, various features are brought together in the examples. This method of the present disclosure is not intended to be interpreted as reflecting the following intention: the examples stated require more features than those clearly stated in each claim. Instead, as reflected in the accompanying claims, the subject matter may be located in less than all the features of a single disclosed example. Thus, the accompanying claims are thus incorporated into the specific embodiments, wherein each claim can remain as a discrete example by itself. Although each claim can remain as a discrete example by itself, it should be noted that although a dependent claim may refer to a specific combination with one or more other claims in the claims, other examples may also include a combination of the subject matter of the dependent claim with other dependent claims, or a combination of each feature with other dependent claims or independent claims. Unless the statement does not intend to make a specific combination, such a combination is proposed in this article. In addition, it is also intended to include the features of a claim that quotes any other independent claim, even if this claim is not directly subordinate to the independent claim.

[0190] Although specific embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that various alternative and / or equivalent implementations may be substituted for the specific embodiments shown and described without departing from the scope of the proposed embodiments. This application is intended to cover any changes or variations of the specific embodiments discussed herein. Therefore, it is intended that the embodiments be limited only by the claims and their equivalents.

Claims

1. A sensor device having a fluid inlet and a fluid outlet, the sensor device comprising: a first micro pump having a normally closed (NC) safety valve, wherein the first micro pump comprises a pump inlet, a pump chamber and a pump outlet, a second micropump having a normally closed safety valve, wherein the second micropump comprises a pump inlet, a pump chamber and a pump outlet, and wherein the first micropump and the second micropump are arranged in fluid series connection and have the same fluid pumping direction, and a sensor having a sensor chamber with a sensor element therein, wherein the sensor is configured to provide a sensor output signal based on a state of a fluid in the sensor chamber, wherein the sensor chamber of the sensor is fluidly coupled between the pump outlet of the first micropump and the pump inlet of the second micropump, and wherein the pump inlet of the first micropump is fluidly coupled to or forms the fluid inlet of the sensor device and the pump outlet of the second micropump is fluidly coupled to or forms the fluid outlet of the sensor device, and The first micropump and the second micropump are configured to provide a defined operating mode of the sensor device based on the corresponding activation states of the first micropump and the second micropump to provide: (1) a defined negative fluid pressure in the sensor chamber, (2) a defined positive fluid pressure in the sensor chamber, or (3) a defined fluid flow through the sensor chamber.

2. The sensor device according to claim 1, wherein: In a first operating mode, the first micropump is in an off state and the second micropump is in an on state to provide the defined negative fluid pressure in the sensor chamber, wherein, in a second operating mode, the first micropump is in an on-state and the second micropump is in an off-state to provide the defined positive fluid pressure in the sensor chamber, and / or Therein, in a third operating mode, the first micropump is in an on state and the second micropump is in an on state to provide the defined fluid flow through the sensor chamber.

3. The sensor device according to claim 2, wherein: The second operation mode includes a first partial operation mode and a subsequent second partial operation mode, wherein, in the first partial operation mode, the first micropump is in an on state and the second micropump is in an off state to provide the defined positive fluid pressure in the sensor chamber, and Therein, in the subsequent second partial operation mode, the first micro pump is in an off state and the second micro pump is in an off state to provide a defined amount of fluid in the sensor chamber.

4. The sensor device according to claim 1, further comprising: A pressure sensor is located in the sensor chamber or is fluidly coupled to the sensor chamber to measure a pressure of a fluid in the sensor chamber.

5. The sensor device according to claim 1, further comprising: A heating element is located in the sensor chamber or is thermally coupled to the sensor chamber to heat the fluid in the sensor chamber and / or the sensor element of the sensor.

6. The sensor device according to claim 1, further comprising: A temperature sensor is located in the sensor chamber or is thermally coupled to the sensor chamber to measure a temperature in the sensor chamber.

7. The sensor device according to claim 1, further comprising: A processing device (50) configured to control the operation mode of the first micropump (10) and the second micropump (20), and to read out a sensor output signal (S) of the sensor (30) in the adjusted operation mode. OUT ).

8. The sensor device according to claim 7, in, The processing device is configured to control an operating mode of a heating element and to read a pressure sensor and / or a temperature sensor coupled to the sensor chamber of the sensor.

9. The sensor device according to claim 7, wherein: The processing device is configured to: (1) control the operating modes of the first micropump and the second micropump to adjust the fluid pressure in the sensor chamber and / or the fluid throughput through the sensor chamber; (2) control the heating element to adjust different temperatures in the sensor chamber; and (3) read the sensor output signal at different temperatures.

10. The sensor device according to claim 7, wherein: The processing device is configured to determine a sensor matrix comprising information (1) about the readout sensor output signals, information (2) about the operation modes of the first micropump and the second micropump, and information (3) about different temperatures in the sensor chamber.

11. The sensor device according to claim 10, wherein: The processing device is further configured to determine the sensor matrix comprising information (4) related to the measured pressure in the sensor chamber.

12. The sensor device according to claim 10 or 11, wherein: The processing device is further configured to determine the sensor matrix comprising information (5) related to the defined fluid flow through the sensor chamber.

13. The sensor device according to claim 7, wherein: The processing device is configured to provide a regulated actuation with a rectangular or sinusoidal actuation signal to the first micropump and the second micropump.

14. The sensor device according to claim 7, wherein: The processing device is further configured to determine the presence, amount or concentration of a target fluid in the fluid in the sensor chamber based on the resulting pressure oscillation curve of the fluid in the sensor chamber.

15. The sensor device according to claim 1, wherein: The sensor element is sensitive to the presence, amount and / or concentration of a target gas in a gas in the sensor chamber, wherein the target gas includes volatile organic compounds (VOCs), CO X , O X or NO X .

16. The sensor device according to claim 1, wherein: The sensor element is a metal oxide based VOC sensor.

17. The sensor device according to claim 1, wherein: The sensor element is an electrochemical sensor having a liquid or solid electrolyte material.

18. The sensor device according to claim 1, wherein: The sensor element is sensitive to a concentration of particulate matter in the fluid in the sensor chamber.

19. A method for sensing the amount or concentration of a target fluid in a medium using the sensor device according to claim 1, the method comprising: adjusting the operation modes of the first micropump and the second micropump; and The sensor output signal of the sensor in a set operating mode is read out.

20. The method according to claim 19, further comprising: setting a temperature of the fluid in the sensor chamber and / or a temperature of the sensor element of the sensor to provide different measurement temperatures in the sensor chamber; measuring a temperature in the sensor chamber; as well as The sensor output signal at different temperatures is read.

21. The method of claim 19, further comprising: adjusting a fluid pressure in the sensor chamber and / or a fluid throughput through the sensor chamber to provide different fluid pressures in the sensor chamber and / or different fluid throughputs through the sensor chamber; measuring a fluid pressure in the sensor chamber and / or a throughput of the fluid through the sensor chamber; as well as The sensor output signal is read out at different fluid pressures in the sensor chamber and / or at the fluid throughput through the sensor chamber.

22. The method of claim 19, further comprising: A sensor output signal matrix is ​​determined which includes information (1) about the read sensor output signals and information (2) about the set operating mode of the first micropump and the second micropump.

23. The method according to claim 22, further comprising: Determine the sensor matrix including information (3) related to different temperatures in the sensor chamber.

24. The method of claim 22, further comprising: Determine the sensor matrix including information (4) related to the measured pressure in the sensor chamber.

25. The method of claim 22, further comprising: Determining the sensor matrix includes information (5) related to a defined fluid flow through the sensor chamber.

26. The method of claim 22, further comprising: The presence, amount or concentration of a target fluid in the fluid in the sensor chamber is determined based on the resulting matrix of sensor output signals.

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