Microfluidic sensing device

Abstract

Main claim: A microfluidic sensing device (1), comprising: • a sensor chip (10), in particular consisting of or comprising a semiconductor chip, configured with one or more microfluidic channels (12) etched directly into the sensor chip (10); • a number of sensing elements (18) integrated within the sensor chip (10) to enable online measurement or assessment of sensor signals due to interaction of fluid within the microfluidic channels (12) with the sensor elements (18), in particular related to fluid mixing or reaction progress.

Description

[0001] 2024PF00673 1

[0002] MICROFLUIDIC SENSING DEVICE

[0003] DESCRIPTION

[0004] TECHNICAL FIELD

[0005] The present invention relates to the field of microfluidic sensing devices , speci fically to an integrated microfluidic system with embedded sensing components for monitoring of di f ferent analytes or of all di f ferent kinds of physical , (bio- ) chemical , optical , and / or electrical properties speci fied by the used sensing element . This invention is particularly relevant to applications requiring compact , preferably precise , and ef ficient sensing in medical diagnostics , biochemical analysis , and other microfluidicbased technologies .

[0006] BACKGROUND

[0007] Microfluidic systems are increasingly used in biomedical and chemical applications for processing small volumes of fluids with high precision and control . Traditional microfluidic devices often require separate sensors to monitor di f ferent parameters such as fluid mixing quality and reaction progress or other parameters of interest . In conventional setups , sensors are typically mounted as external units , which involves additional fabrication steps and complicates the overall device design . The need to add a separate sensing component also limits the potential for device miniaturi zation and integration, which are essential for point-of-care diagnostics and portable biochemical analysis systems .

[0008] Recent advances in semiconductor and microfabrication techniques have enabled the production of highly integrated devices on a chip scale . However, current microfluidic systems still lack ef ficient ways to integrate inline sensing directly within the microfluidic pathways , resulting in 2024PF00673 2 limitations on scalability and usability in real-time analysis applications .

[0009] SUMMARY

[0010] The present invention provides a microfluidic sensing device , comprising :

[0011] • a sensor chip, in particular consisting of or comprising a semiconductor chip, configured with one or more microfluidic channels etched directly into the sensor chip ;

[0012] • a number of sensing elements integrated within the sensor chip to enable online measurement or assessment of sensor signals due to interaction of fluid within the microfluidic channels with the sensor elements , in particular related to fluid mixing or reaction progress .

[0013] Thus , the present invention provides an integrated microfluidic sensing device that incorporates sensing directly within the microfluidic channels on a sensor chip . By etching microfluidic channels directly into the sensor substrate , the invention achieves a compact , monolithic structure that integrates both fluid handling and sensing in a single device . This innovative design eliminates the need for external sensors , reduces the number of production steps , and enables wafer-level fabrication, thereby simpli fying the manufacturing process and reducing overall device si ze .

[0014] However, this does not exclude the possibility that the sensing elements and / or an on-board computing chip or unit communicate with an external computing unit for the evaluation and / or processing of the sensor signals .

[0015] The integrated microfluidic sensing system can introduce light vertically or hori zontally through the channels , allowing for versatile measurement options , such as phase shi ft detection or intensity measurement besides others . This flexibility enables the device to perform real-time , inline 2024PF00673 3 monitoring of different parameters and / or properties such as fluid mixing quality and reaction progress, meeting the demands of highly compact and efficient microfluidic applications .

[0016] The primary objectives of this invention are as follows:

[0017] • To provide an integrated sensing solution within microfluidic devices that allows for real-time monitoring of fluid mixing and reaction processes.

[0018] • To reduce the complexity of manufacturing microfluidic sensors by integrating microfluidic channels and sensing elements into a single chip.

[0019] • To enable wafer-level production and testing, enhancing scalability and reducing production costs.

[0020] • To offer flexible light coupling options, including vertical and horizontal configurations, to support multiple measurement principles, such as phase-shift detection .

[0021] By addressing these objectives, the invention offers a compact, reliable, and efficient solution for inline sensing in microfluidic applications, suitable for use in medical diagnostics, biochemical assays, and other fields requiring high precision fluid monitoring in miniaturized environments.

[0022] Key benefits of this invention are as follows:

[0023] • Compact design: A smaller, integrated form factor reduces the system's footprint, which is crucial for applications where space is limited.

[0024] • Ease of manufacturing: Direct etching on wafers simplifies the production process, allowing for batch processing and better scalability.

[0025] • Flexible light integration: Options for light coupling (vertical or horizontal) enable diverse measurement methods, expanding the device's adaptability for various sensing needs.

[0026] Preferred embodiments are subject of the dependent claims and the subsequent description. 2024PF00673 4

[0027] In a preferred embodiment , the microfluidic channels are fabricated directly on or within a semiconductor wafer, speci fically in a substrate layer . This approach leverages standard semiconductor manufacturing techniques , allowing the channels to be etched with high precision . Integrating microfluidic structures within a semiconductor substrate also enhances durability and enables miniaturi zation, as it eliminates the need for additional supporting layers or materials . This results in a compact device that can be manufactured at wafer scale , making it cost-ef fective and suitable for high-throughput production .

[0028] In a preferred embodiment , the sensor chip includes one or more passivation layers that can be optically transparent , allowing light to pass through the chip for optical measurements . These passivation layer ( s ) serve as a protective barrier ( s ) , shielding the sensing components from chemical or environmental damage or interference and in the case of a transparent passivation layer without signi ficantly interfering with certain light properties . The optical transparency of the layer enables light-based analysis , ensuring that the sensing elements can capture accurate data on fluid properties within the channels .

[0029] In a preferred embodiment , the microfluidic channels are sealed using dry films or wafer bonding, creating a robust and compact structure ideal for miniaturi zed sensing applications . In particular Si-to-glass bonding may be employed . Using dry films or wafer bonding as sealing methods enhances the durability and longevity of the channels by preventing fluid leakage and maintaining structural integrity . This sealing technique also supports high- precision measurements , as it minimi zes the risk of contamination and ensures consistent flow conditions within the microfluidic channels . According to the actual requirements the sealing method needs to be selected . In addition, e . g . glass coupons could be glued to seal the microfluidic channels ; this could be achieved by a pick-and- 2024PF00673 5 place processes . Direct mounting on e . g . a PCB or other suitable substrate and sealing with di f ferent soldering processes might be other options .

[0030] In this context , dry films preferably are photopolymer materials used in the fabrication and sealing of microfluidic devices . These films are typically applied in a solid state and then exposed to UV light to create a patterned structure that can ef fectively seal microfluidic channels . Laser patternable dry films could be applied too ; those are widely used in PCB production . Due to the big range of available materials all kinds of required material properties could be implemented . I f the actual design requires an optical transparent material , it is available . Alternatives might not be transparent at the full optical range but have enhanced properties for durability . Parameters like CTE mismatch, designated working temperature range etc . can be adj usted . Due to their optically transparent nature , dry films allow light to pass through with minimal loss , which is essential for optical sensing applications within the channels (depending on the design, the light used for optical sensing could be coupled into the sample from di f ferent directions ; depending on this , the exact dry film material is chosen) .

[0031] Dry films also of fer advantages in the manufacturing process , as they can be easily integrated into existing fabrication workflows . Their application allows for ef ficient wafer-level sealing, streamlining production and reducing the need for additional assembly steps . The versatility of dry films makes them suitable for a range of applications , as they can be formulated to have speci fic chemical properties tailored for various microfluidic environments , thereby enhancing the performance and reliability of integrated microfluidic sensing devices .

[0032] In a preferred embodiment , the microfluidic channels comprise j oints where two or more channels unite . This design enables the mixing of di f ferent fluids within the microfluidic device , a feature that is essential for many biochemical and 2024PF00673 6 medical applications . By integrating j unctions where channels converge , the device can monitor reactions as fluids mix and interact . This capability allows for real-time analysis of complex fluid interactions , providing valuable data in diagnostics and chemical processing .

[0033] In a preferred embodiment , the microfluidic channels are accessible from outside the sensor chip via inlets and outlets . This accessibility facilitates the inj ection and extraction of fluids , making it easy to introduce samples and remove waste . Inlets and outlets also make the device compatible with automated systems for fluid handling, which is beneficial for applications requiring high throughput and minimal manual intervention . This feature extends the device ' s adaptability to various fluidic protocols and procedures .

[0034] In a preferred embodiment , the microfluidic channels are assigned multiple sensing areas within the sensor chip, allowing for simultaneous measurement of di f ferent fluid parameters and / or changes of the sensor signal due to interactions of the fluid with the sensor . Multiple sensing areas provide comprehensive data by enabling the detection of several fluid properties , such as temperature , concentration, or pH, within the same device . This multiplexing capability enhances ef ficiency and data quality, especially in applications where multiple analytes need to be monitored concurrently .

[0035] In a preferred embodiment , the sensing element is configured to detect phase shi fts in light passing through the fluid in the microfluidic channels , providing data on fluid composition or reaction progress . Phase-shi ft detection of fers an alternative to traditional intensity-based measurements , allowing for more detailed analysis of the fluid' s properties . This method is particularly advantageous for applications requiring precise monitoring of chemical or physical changes in fluids , as it can provide insights into reaction kinetics and material composition . 2024PF00673 7

[0036] In a preferred embodiment , the sensor chip is configured to introduce light through a light-guiding layer situated between a substrate layer with the microfluidic channels and a sensing layer with the sensing elements , or situated above or below the sensing elements . This light-guiding layer facilitates interactions of light with the fluid to change certain light properties to enable di f ferent kind of measurements such as phase-shi ft detection and or enabling more versatile measurement techniques . By guiding light through an intermediary layer, the system can maintain control over the light ' s path and optimi ze interactions with the fluid, improving measurement accuracy and enabling the detection of subtle fluid changes .

[0037] In a preferred embodiment , the sensing elements are reali zed within, next to , above , below etc . a CMOS element , which provides functionality for detecting changes of all di f ferent kinds of physical , (bio- ) chemical , optical , and electrical properties such as light absorption, light emission, light intensity, phase shi fts , changes in resistivity, induction, temperature and / or others . CMOS technology is advantageous due to its compatibility with standard semiconductor manufacturing processes , allowing the sensing elements to be fabricated at a low cost and high yield . Additionally, CMOS sensors of fer excellent sensitivity and can be easily integrated with electronic components for signal processing, making the device suitable for complex analytical applications .

[0038] In particular, the according sensing element can comprise or consist of a number of photodiodes .

[0039] In a preferred embodiment , the sensor chip is configured to enable wafer-level testing of microfluidic and optical functionality before final packaging . Wafer-level testing ensures that each device meets performance speci fications before assembly, reducing the likelihood of defects in the final product . This approach not only improves quality 2024PF00673 8 control but also lowers manuf cturing costs by identi fying and recti fying issues early in the production process .

[0040] In a preferred embodiment , the sensor chip is capable of online measurements of fluid mixing quality or reaction progress within the microfluidic channels without requiring an external sensing unit . This sel f-contained capability is beneficial for real-time applications , as it eliminates the need for external measurement devices and allows for continuous monitoring . The integrated sensing functionality makes the device highly portable and ef ficient , which is particularly useful in field diagnostics and other on-site applications .

[0041] In a preferred embodiment , the sensor chip includes electrical contacts through wire bonding or through-silicon vias ( TSVs ) for signal processing . Electrical contacts enable data trans fer from the sensing elements to external processing units , allowing for ef ficient signal capture and analysis . TSVs , in particular, provide a compact and reliable connection method, further enhancing the device ' s miniaturi zation and robustness .

[0042] In a preferred embodiment , a method for manufacturing the microfluidic sensing device involves integrating sensing elements within the sensor chip on either its front side or back side , etching microfluidic channels from the opposite side , and sealing the channels with a layer, which can be transparent . This method allows for precise alignment of sensing and fluidic features , facilitating real-time monitoring of fluid mixing or reactions . This layered approach optimi zes the integration of optical and microfluidic functionalities , ensuring a reliable and scalable manufacturing process .

[0043] In one preferred embodiment , the etching process for fabricating microfluidic channels in a microfluidic sensing device begins with substrate preparation, which typically involves cleaning a silicon wafer or glass substrate to 2024PF00673 9 ensure a contaminant- free surface . A photoresist layer may then be applied, and a mask containing the desired channel pattern is placed over the substrate . Upon exposure to ultraviolet (UV) light , the photoresist undergoes a chemical change , allowing selective removal in the development step, where either the exposed or unexposed areas are washed away, creating a patterned layer .

[0044] Following the development , the substrate undergoes the etching process to create the microfluidic channels . This can be accomplished using wet etching, where the substrate is submerged in a chemical solution that selectively dissolves the exposed areas , or dry etching, which employs plasma or reactive ion etching for more precise and controlled channel geometries . Wet etching is generally isotropic, while dry etching of fers anisotropic results , leading to well-defined channel shapes .

[0045] After etching, the remaining photoresist is stripped away, revealing the etched microfluidic channels . These channels can then be sealed with a transparent layer or dry films to create airtight structures suitable for fluid transport . This process not only facilitates the integration of optical sensing elements but also ensures that the microfluidic channels are designed to meet the speci fic requirements for ef fective measurement and monitoring within the microfluidic sensing device .

[0046] In summary, the present invention is about a highly integrated microfluidic-optical sensor chip designed for real-time , in-situ monitoring of reactions and fluid mixing within microfluidic systems . By embedding microfluidic channels directly within the sensor, it reduces production complexity, minimi zes system si ze , and of fers enhanced flexibility for optical measurement techniques , making it ideal for applications in the medical and biochemical fields .

[0047] BRIEF DESCRIPTION OF THE DRAWINGS 2024PF00673 10

[0048] Exemplary embodiments of the invention are subsequently discussed with reference to the accompanying drawings .

[0049] FIG . 1 comprises a highly schematic cross-sectional view of a microfluidic sensing device according to the invention .

[0050] This figure illustrates a cross-sectional view of the microfluidic sensing device , highlighting the integration of microfluidic channels etched directly into the sensor chip substrate . The cross-section shows the positioning of optical sensing elements embedded within the sensor chip, as well as the transparent passivation layer that allows light transmission for optical measurements . The figure also depicts the layered configuration, including the substrate , sensing areas , light-guiding layer, and sealed channels .

[0051] FIG . 2 comprises a highly schematic plan view (partially cut ) of the microfluidic sensing device .

[0052] This figure provides a partially cut plan view of the microfluidic sensing device , showing the layout of the microfluidic channels and multiple sensing areas distributed within the sensor chip . The inlets and outlets for fluid access are visible , along with j oints where channels converge , enabling fluid mixing . The optical sensing elements are represented in relation to the channels , demonstrating how they align with di f ferent sensing areas to allow simultaneous measurements of fluid parameters .

[0053] FIGs 3 to 6 show various variations of the internal design or construction of the sensing device , all of them given in cross-sectional view .

[0054] DETAILED DESCRIPTION

[0055] The present invention relates to an integrated microfluidic sensing device designed to measure fluid properties such as mixing quality and reaction progress in real time . This device combines fluid handling and optical sensing within a 2024PF00673 11 compact , multi-layered sensor chip suitable for miniaturi zed applications , such as medical diagnostics , biochemical analysis , and point-of-care testing .

[0056] Referring to FIG . 1 , a cross-sectional view of the microfluidic sensing device is shown . At the core of the device is a substrate layer 14 , into which one or more microfluidic channels 12 are directly etched . These channels 12 serve as pathways for fluid samples , enabling inline analysis of various fluid properties . The direct etching of microfluidic channels 12 into substrate 14 minimi zes the device ' s complexity and si ze , resulting in a compact , robust structure .

[0057] Directly above substrate 14 is a light-guiding or transparent layer 20 , which facilitates optical measurements within the microfluidic channels 12 . This layer 20 is optically transparent , allowing light to pass through and interact with the fluid in the channels below . Layer 20 supports both hori zontal and vertical light coupling, depending on the configuration . The terms "hori zontal" and "vertical" refer to the orientation of the sensor chip 10 when arranged flat (hori zontally aligned) as in FIG . 1 for convenience in this context .

[0058] The shown setup incorporates two exemplary light sources . A first light source 36 is positioned at the side edge of the device , coupling light hori zontally into light-guiding layer 20 , allowing light to travel parallel to substrate 14 . This configuration enables phase-shi ft detection based on the interaction of light with the fluid in channels 12 . A second light source 38 is positioned below the device , coupling light vertically through the lowermost transparent sealing layer 16 . This vertically coupled light facilitates measurements based on intensity changes as light travels through the fluid in the microfluidic channels 12 .

[0059] Positioned above light-guiding layer 20 is the CMOS layer 32 , which contains optical sensing elements 18 . These elements 18 2024PF00673 12 are aligned with microfluidic channels 12 and detect changes in light intensity or phase shi ft as light interacts with the fluid . CMOS layer 32 enables high-sensitivity optical measurements using standard CMOS-compatible technology, making the device suitable for large-scale production . The alignment of sensing elements 18 within CMOS layer 32 ensures precise monitoring of fluid properties at di f ferent points in the channels 12 .

[0060] Below the substrate layer 14 , at the base of the device , is a transparent sealing layer 16 that encapsulates microfluidic channels 12 , ensuring fluid containment and protection from external contamination . The transparency of sealing layer 16 maintains the optical path, allowing light from light source 38 to pass unobstructed through the microfluidic channels 12 for optical sensing when vertically coupled from below .

[0061] For electrical interfacing, soldering balls 34 are positioned at the bottom of the device , extending from substrate layer 14 through sealing layer 16 , to provide stable electrical connections for sensor chip 10 . These soldering balls 34 enable signal transmission from sensing elements 18 to external processing systems . Through-silicon vias ( TSVs ) , though not shown, may also be used to provide alternative or additional electrical connections from CMOS layer 32 to external systems .

[0062] FIG . 2 , a partially cut plan view of the device , shows the layout of microfluidic channels 12 within substrate 14 . Channels 12 include inlets 24 and outlets 26 , which provide access points for fluid introduction and removal . This arrangement supports ef ficient fluid handling, facilitating integration with automated fluid systems for high-throughput applications .

[0063] Multiple sensing areas 28 are distributed along microfluidic channels 12 within the device , allowing for simultaneous or sequential measurement of various fluid parameters . These sensing areas 28 enhance the device ' s analytical capabilities 2024PF00673 13 by providing real-time data on fluid properties at different points in channels 12.

[0064] Microfluidic channels 12 also include joints or junctions 30, where two or more channels unite, allowing for fluid mixing and interactions. Optical sensing elements 18 near these junctions 30 capture real-time changes in fluid properties as streams merge, providing insights into mixing efficiency, reaction progress, and other critical fluid dynamics.

[0065] In summary, the multi-layered structure shown in FIGS. 1 and 2 — comprising substrate 14 with microfluidic channels 12, optional light-guiding layer 20, CMOS layer 32 with sensing elements 18, and transparent sealing layer 16 — forms a compact, robust device that integrates fluid handling and optical sensing. The addition of external light sources 36 and 38 (may be ambient light as well) enables versatile measurement configurations for a wide range of analytical applications, offering precision, simplified production, and a reduced device footprint suitable for diverse microfluidicbased systems.

[0066] Within the scope of the claims, there are a number of possible variations, some of which are shown in FIGs 3 to 5 in cross-sectional view.

[0067] In general, not all of the layers or structures of the sensing device 1 necessarily extend over the whole lateral extension of the sensor chip 10, as can be seen in FIG. 2. Rather, there may be breaks, interruptions, or free sections in the corresponding layer or bulk. For example, the sensing elements 18, the microfluidic channels 12, and / or other elements may be located in certain areas or sections only when viewed from above or below.

[0068] Furthermore, the "depth" or height of certain elements like the microfluidic channels 12 may vary locally, as shown in FIG. 3. In some areas they may reach through the sensing 2024PF00673 14 layer and / or the light guiding layer 20 (if present) , in others they may be confined to the substrate layer 14.

[0069] Furthermore, there may be a third light source 40 above the sensing device 1, coupling in light from above, for example through an uppermost additional layer 42, for example an optical transparent or light-guiding layer.

[0070] Of course, from the three possible light source locations (above, below, at the side) only one (or even none) may actually be occupied with a light source. Each light source 36, 38, 40 may emit light in the visible and / or any other range of the spectrum.

[0071] As shown in FIG. 4, there may be internal light sources 44 like LED and / or VCSEL integrated into the sensor chip 10. In particular, these internal light sources 44 or light emitters may be positioned to emit light into the microfluidic channels 12, illuminating a fluid therein, thus stimulating or supporting light-sensitive (chemical) reactions, for example. Due to these internal light sources 44, external light sources 36, 38, 40 may not be necessary at all. Rather, in this context it may be required or beneficial to have optically non-transparent or opaque (cover or other) layers within sensor chip 10 to shield the microfluidic channels 12 from external illumination.

[0072] For the sealing layer 16, a direct bondable material may be used, for example Si or glass, in particular if an optically transparent medium is desired. That is, a glass waver or Si waver may be applied directly to a bondable surface of the substrate layer 14 or bulk of the sensor chip 10 to form a fusion bond. Etching or laser drilling may be used for forming required connections. Alternatively, hybrid bond or solder techniques or laser patternable dry films like ABF may be applied.

[0073] Alternatively, a sealing layer 16 or sealing cover may be glued to the bulk of the sensor chip 10. Pick and place 2024PF00673 15 techniques may be applied to facilitate this. In FIG. 5 a glue layer 46 is indicated by reference.

[0074] FIG. 6 shows a further variation in which internal light sources 44 (LEDs, VCSELs, etc.) are arranged inside the microfluidic channels 12. Alternatively, they might be incorporated in the substrate layer 14 applied for sealing.

[0075] Where appropriate, all the previous embodiments may be combined in any useful way.

[0076] 2024PF00673 16

[0077] LIST OF REFERENCE S IGNS microfluidic sensing device 1 sensor chip 10 microfluidic channel 12 substrate layer 14 sealing layer 16 sensing element 18 light-guiding / transparent layer 20 inlet to microfluidic channels 24 outlet from microfluidic channel 26 sensing area 28 j unction 30

[0078] CMOS layer 32 soldering ball 34 light source 36 light source 38 third light source 40 additional layer 42 internal light source 44 glue layer 46

Claims

2024PF00673 17CLAIMS1. A microfluidic sensing device (1) , comprising:• a sensor chip (10) , in particular consisting of or comprising a semiconductor chip, configured with one or more microfluidic channels (12) etched directly into the sensor chip (10) ;• a number of sensing elements (18) integrated within the sensor chip (10) to enable online measurement or assessment of sensor signals due to interaction of fluid within the microfluidic channels (12) with the sensor elements (18) , in particular related to fluid mixing or reaction progress.

2. The device (1) of claim 1, wherein the microfluidic channels (12) are fabricated directly on / in a semiconductor wafer, in particular within a substrate layer (14) .

3. The device (1) of any of the preceding claims, wherein the sensor chip (10) includes a passivation layer that may be optically transparent, enabling transmission of light through the sensor chip (10) for optical measurements.

4. The device (1) of any of the preceding claims, wherein the microfluidic channels (12) are sealed using dry films or wafer bonding.

5. The device (1) of any of the preceding claims, wherein the microfluidic channels (12) comprise joints or junctions (30) where two or more microfluidic channels (12) unite.

6. The device (1) of any of the preceding claims, wherein the microfluidic channels (12) are accessible from outside the sensor chip (10) via inlets (24) and outlets (26) .

7. The device (1) of any of the preceding claims, wherein the microfluidic channels (12) are assigned multiple sensing areas (28) within the sensor chip (10) .2024PF00673 188. The device (1) of any of the preceding claims, wherein the sensing element (18) is configured to detect at least one kind of physical, (bio-) chemical, optical, and / or electrical properties such as light absorption, light emission, phase shifts, changes in resistivity, induction, and / or temperature, in particular optical properties related to light passing through fluid in the microfluidic channels (12) and interacting with said fluid.

9. The device (1) of any of the preceding claims, wherein the sensor chip (10) includes a configuration to introduce light through a light-guiding layer (20) , wherein the lightguiding layer can be between a substrate layer (14) with the microfluidic channels (10) and a sensing layer with the sensing elements (18) or is on top of the sensing elements (18) or is on top of the substrate layer (20) .

10. The device (1) of any of the preceding claims, wherein the sensing elements (18) are realized within, next to, on top or under a CMOS layer (32) with functionality for detecting changes of at least one kind of physical, (bio-) chemical, optical, and / or electrical properties, such as light absorption, light emission, light intensity, phase shifts, changes in resistivity, induction, and / or temperature .

11. The device (1) of any of the preceding claims, wherein the sensor chip (10) is configured to enable wafer-level testing of microfluidic and physical, (bio-) chemical, optical, and / or electrical functionality before final packaging .

12. The device (1) of any of the preceding claims, wherein the sensor chip (10) is capable of online measurement or assessment of sensor signals due to interaction of fluid within the microfluidic channels (12) with the sensor elements (18) without requiring an external sensing unit.2024PF00673 1913. The device (1) of any of the preceding claims, further comprising electrical contacts to the sensor elements (18) through wire bonding or through-silicon vias (TSVs) for signal processing.

14. A method for manufacturing a microfluidic sensing device (1) , in particular the device (1) of any of the preceding claims, comprising:• integrating a number of sensing elements (18) which are preferably related to physical, (bio-) chemical, optical and / or electrical properties within a sensor chip (10) on either its front side or back side;• etching microfluidic channels (12) directly into a sensor chip (10) from a side opposite to sensing elements (18) ;• sealing the microfluidic channels (12) with a layer, which can be transparent.

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