Patent Description:
There are numerous ways to sample bodily fluids, for example by using a syringe. This is cumbersome and improved alternatives exist, such as by using microneedles. Although many application fields exist for microneedles, the vast majority of published microneedles concern drug delivery in various forms.

For example the concept of an array of miniaturized needles for drug delivery purposes dates back to the <NUM>'s <CIT>. One of the earliest reported microneedles in the scientific literature was an out-of-plane silicon needle array featuring <NUM>, <NUM> long, needles on an area of <NUM>×<NUM> in "<NPL>et al. Eventually bio sensing technology will be to the 21st century what microelectronics was to the second half of the 20th century.

Integrated circuits (IC) have had an enormous impact on our daily life today and making use of the same miniaturization and cost benefits of volume manufacturing bio sensing might move clinical diagnosis and health monitoring from expensive laboratories to small hand-held consumer devices. Sampling of an analyte to be measured is a prerequisite for bio sensing. Many of the designs described in scientific papers have the purpose of extracting bodily fluids. For example blood or interstitial fluid, ISF. Different bodily fluids demand a variety of solutions, for example successful extraction of blood has been demonstrated with use of the natural "overpressure" in the vascular system, while successful extraction of ISF without under-pressure, through diffusion or other mechanisms such as capillary forces are rare or even non-existing. The terms "under-pressure" and "sub-pressure" are used as equivalents in the present disclosure.

A previously known document <CIT> discloses a sensor assembly for sampling of a bodily fluid comprising two substrates. One of the substrate comprises micro needles for piercing the stratum corneum and sampling interstitial fluid by capillary action. The second substrate supports micro sensors, a control circuitry and a reference electrode. Perforations in the second substrate are used to vent and to incorporate electrical conductors and provide electrical access to the sensors and control circuitry.

Independent of method of sampling, the sample has to be transferred to the sensing device in a controlled manner. In order to further improve usage and prevent mistakes, this can preferably be performed in an integrated unit.

The aim of the present invention is to set aside the abovementioned drawbacks and shortcomings of the previously known sensor assemblies and to provide an improved solution for sampling of bodily fluids.

In order to improve the extraction of fluids such as ISF an under-pressure can be applied. This is however difficult to combine with collecting readings from an integrated sensor. It has been realized that a fluid path extending through the sensor assembly is beneficial. In addition, in order to have an operational sensor the comprised electrodes need to be in communicating connection with an exterior part of the sensor assembly.

An object of the invention is to provide an improved sensor assembly having a fluid path extending through the assembly and integrated operational sensor that allows easy sampling of bodily fluid, such as interstitial fluid, ISF.

The object of the invention is met in a sensor assembly as defined in the appending claims.

In a first aspect, the present invention relates to a sensor assembly for sampling of a bodily fluid comprising a first substrate, a second substrate and a sensor. The first substrate comprises at least one capillary bore defining a fluid path. The fluid path is extending through said first substrate from a top side to a fluid channel on a bottom side of said first substrate. The second substrate is arranged in connection with the first substrate and the fluid channel of the first substrate is in fluid communication with a first metallised via and a second metallised via formed in the second substrate. Thereby extending the fluid path through the first metallised via and the second metallised via. The sensor comprises a first electrode and a second electrode. The first electrode and the second electrode is arranged on the second substrate in fluid communication with the fluid channel of the first substrate. The first electrode is in electric contact with the first metallised via and the second electrode is in electric contact with the second metallised via.

In embodiments, the first substrate may comprise a plurality of bores.

In embodiments, the sensor assembly may further comprise means for applying sub-pressure to the fluid path to draw fluid from the capillary bores towards the second substrate.

In embodiments, the sensor assembly may further comprise a plurality of microneedles integrally formed on the first substrate. Each microneedle may comprise an elongated body extending from a distal end thereof to a proximal end thereof on the first substrate along a longitudinal axis. Each microneedle may further have a bevel at the distal end. The capillary bores may extend through the elongated body in a longitudinal direction thereof and further define the fluid path. The proximal end may be integrally formed with the first substrate and the fluid path may be in fluid communication with the fluid channel of the first substrate.

In embodiments, the second substrate may be arranged in connection with the first substrate on a side opposite the plurality of microneedles.

In embodiments, the first electrode may be shaped as a spiral and the second electrode may be shaped as a spiral, and wherein the spiral shapes of the first and second electrodes are nested.

In embodiments, the sensor is located on a side of the second substrate directed towards the first substrate.

In embodiments, the sensor may at least partly be located on the side of the second substrate that is directed towards the first substrate.

In embodiments, the sensor may at least partly be located in the via.

In embodiments, the via may further comprise a signal path that may be extending through the second substrate and the sensor may be arranged in electrical connection with the signal path.

In embodiments, the via may be hollow, thereby providing fluid communication between two opposite sides of the second substrate.

In embodiments, the sensor may be an electrochemical sensor. Electrochemical sensors are known in the art. One known type of electrochemical glucose sensor is the Clark biosensor. This sensor is based on a thin layer of glucose oxidase (GOx) on an oxygen electrode. The readout is the amount of oxygen consumed by GOx during enzymatic reaction with the substrate glucose. A more detailed description of biosensors, such as the Clark type, can be found in<NPL>. The described sensors may be adapted for use in the present invention. In such embodiments, at least one electrode of the sensor is coated with an enzyme, such as a redox enzyme. Enzymes useful in the present invention are oxidoreductases acting on an electron donor with oxygen as acceptor. Such enzymes are generally classified in the group EC <NUM>. X in the enzyme nomenclature of the International Union of Biochemistry and Molecular Biology. One preferred enzyme is glucose oxidase (EC <NUM>.

In embodiments, the sides of the via may further comprise a substance with a specified surface energy. By this, the flow behaviour of the fluid may be controlled by its interaction with the specified surface energy.

In embodiments, the wall surface of the via may further be made hydrophobic, such as by coating with a hydrophobic substance.

In embodiments, the wall surface of the via may further be made hydrophilic, such as by coating with a hydrophilic substance.

In embodiments, a cross-sectional area of the capillary bore in the distal end may be larger than the cross-sectional area of the capillary bore in the proximal end.

In embodiments, the fluid channel may further comprise a decreasing cross-sectional area in order to further enhance a fluid flow in the fluid channel.

The term cross-sectional area means the area of a cross section of an object. The cross section is the intersection of the object and a plane. In comparing different cross-sectional areas it is understood that the intersecting planes are parallel unless otherwise stated.

In embodiments, the first substrate may further comprise a frame located on the same side as the plurality of microneedles, wherein the frame at least partly surrounds an area on the first substrate having the plurality of microneedles.

In embodiments, the frame may have a height in a direction extending from the substrate that is equal or higher than the height of the plurality of microneedles.

In embodiments, the cross sectional area of the capillary bore of the microneedles may gradually decrease from the distal end towards the proximal end along the longitudinal direction. This contributes to an enhanced fluid flow through the capillary bore, by means of capillary force acting on the fluid in the capillary bore.

In embodiments, the cross-section (crosswise to the longitudinal direction) of the capillary bore may further comprise at least one rounded corner. This contributes to the wetting of the capillary bore, which has a positive effect on the fluid flow.

In embodiments, the capillary bore may have a triangular cross-section. A triangular cross-section has been demonstrated to provide a very good fluid flow in the capillary bore. A triangular cross-section within this application encompasses cross sections with substantially triangular shape, i.e. edges with convex or concave shape or straight shape, corners with sharp angles and corners with blunt angles as well as rounded corners.

In embodiments, the walls of the capillary bore may comprise hydrophilic surfaces, which enhances the fluid flow in the capillary bore.

In embodiments, the fluid channel may be configured to provide an under-pressure, relative the atmospheric pressure, to the capillary bore, whereby fluid flow through the capillary bore is enhanced. An under-pressure may for example be created with a syringe connected to the fluid channel.

In embodiments, the second substrate may be operatively connected to the first substrate by means of anodic or direct bonding, which provides a strong and fluid tight seal without the risk of clogging the fluid channels with adhesive.

In a second aspect, the present invention relates to a measurement device comprising a sensor assembly according to the invention, further comprising a suction device arranged in connection with the sensor assembly on a side opposite the one or plurality of microneedles and in fluid communication with the first via and the second via of the second substrate, thereby providing a pressure difference through the vias and the fluid channel.

In embodiments, the one or plurality of microneedles integrally formed on the first substrate may comprise an elongated body extending from a distal end with a bevel to a proximal end on the substrate along a longitudinal axis. The elongated body may comprise a capillary bore extending in a longitudinal direction thereof and that defines a fluid path. The proximal end may be integrally connected with the substrate and the capillary bore may be in fluid communication with a fluid channel of the first substrate. Further, the cross-sectional area of the capillary bore in the distal end may be larger than the cross-sectional area of the capillary bore in the proximal end.

A bevel is referred to as a bevelled surface relative the longitudinal axis of the capillary bore.

A more thorough understanding of the abovementioned and other features and advantages of the present invention will be evident from the following detailed description of embodiments with reference to the enclosed drawings, on which:.

The present invention is based on the insights disclosed. When examined carefully it's clear that the sensor assemblies in the prior art for sampling of bodily fluids either can't apply under-pressure or be provided in an integrated unit. Solution that are able to apply under-pressure rely on transfer of the sample to the sensing device. Similarly, solutions that are able to provide integrated units are not able to provide under-pressure. Under-pressure which improves or even is demanded for some samplings.

In order to combine the improved extraction of fluids such as ISF by use of an applied under-pressure with the improve usage that an integrated unit provides, an improved sensor assembly is described.

For increased understanding, some figures illustrates the substrates of the sensor assembly as separated, it is understood that substrates illustrated as separated typically is joint. For an example, the substrates may be joint by means of anodic/direct bonding, which provides a strong and fluid tight seal without the risk of clogging the fluid channels with adhesive. Other means of joining the substrates may be envisioned, such as clamping or by an adhesive.

<FIG> is a schematic cross section view of a sensor assembly <NUM> according to an embodiment of the present invention having a first substrate <NUM>, a second substrate <NUM> and a sensor <NUM>.

The first substrate <NUM> has a capillary bore <NUM> defining a fluid path <NUM> extending through said first substrate <NUM> from a top side <NUM> to a fluid channel <NUM> on a bottom side <NUM> of said first substrate <NUM>.

The second substrate <NUM> is arranged in connection with the first substrate <NUM>, the fluid channel <NUM> of the first substrate is in fluid communication with a first metallised via <NUM> and a second metallised via <NUM> formed in the second substrate <NUM>, thereby extending the fluid path <NUM> through the first metallised via <NUM> and the second metallised via <NUM>.

The sensor <NUM> comprising a first electrode and a second electrode is arranged on the second substrate <NUM> in fluid communication with the fluid channel <NUM> of the first substrate <NUM>. The first electrode is in electric contact with the first metallised via <NUM> and the second electrode is in electric contact with the second metallised via <NUM>.

The first metallised via <NUM> and the second metallised via <NUM> may be hollow, thereby providing fluid communication between two opposing sides of the second substrate <NUM>.

The sides of the vias may further comprise a substance with a specified surface energy. By this, the flow behaviour of the fluid may be controlled by its interaction with the specified surface energy. For an example, the sides of the via may comprise a hydrophobic substance or a hydrophilic substance.

The interior dimensions and geometry of the bore may also be designed to allow capillary forces to act on liquid in part or all the way through the fluid channel of the sensor assembly <NUM>. These capillary forces may be used together with an applied under-pressure.

In addition, the sensor assembly may further comprise means for applying under-pressure to the fluid path to draw fluid from the capillary bores towards the second substrate. An under-pressure may for example be created with a syringe connected to the fluid channel.

<FIG> is a schematic perspective view of a sensor assembly <NUM> shown from above. The sensor assembly <NUM> is having a first substrate <NUM>, a second substrate <NUM> and a sensor <NUM>.

The first substrate <NUM> has a capillary bore <NUM>, here shown on a microneedle, defining a fluid path extending through said first substrate <NUM> from a top side <NUM> to a fluid channel <NUM> on a bottom side of said first substrate <NUM>. The first substrate is here shown with a plurality of microneedles. In other embodiments, the first substrate <NUM> may be without microneedles, the capillary bore <NUM> may then be located on the top side <NUM>.

The second substrate <NUM> is illustrated at a distance from the first substrate <NUM>, the fluid channel of the first substrate is in fluid communication with a first metallised via <NUM> and a second metallised via <NUM> formed in the second substrate <NUM>, thereby extending the fluid path through the first metallised via <NUM> and the second metallised via <NUM>.

The sensor <NUM> comprising a first electrode <NUM> and a second electrode <NUM> is arranged on the second substrate <NUM> in fluid communication with the fluid channel of the first substrate <NUM>. The first electrode <NUM> is in electric contact with the first metallised via <NUM> and the second electrode <NUM> is in electric contact with the second metallised via <NUM>.

The sensor assembly <NUM> may have one or a plurality of microneedles. The microneedles may be integrally formed on the first substrate <NUM>. Each microneedle may comprise an elongated body extending from a distal end thereof to a proximal end thereof on the top side <NUM> of the first substrate <NUM> along a longitudinal axis. Each microneedle may further have a bevel at the distal end. The capillary bores may extend through the elongated body in a longitudinal direction thereof and further define the fluid path. The proximal end may be integrally formed with the first substrate <NUM> and the fluid path may be in fluid communication with the fluid channel <NUM> of the first substrate <NUM>.

The sensor <NUM> is here illustrated on a side of the second substrate <NUM> that is directed towards the first substrate <NUM>. In other examples, the sensor may comprise an elongated portion extending in the vias in the second substrate <NUM>. For example, the sensor may be a electro chemical sensor.

The vias may each further comprise a signal path that may be extending through the second substrate <NUM>. The sensor <NUM> may be arranged in electrical connection with the signal paths.

The first electrode <NUM> may be shaped as a spiral and the second electrode 232may be shaped as a spiral, and wherein the spiral shapes of the first and second electrodes may be nested.

<FIG> is a schematic perspective view of a sensor assembly <NUM> shown from below. The sensor assembly <NUM> is having a first substrate <NUM>, a second substrate <NUM> and a sensor.

The first substrate <NUM> has a capillary bore defining a fluid path extending through said first substrate <NUM> from a top side to a fluid channel <NUM>, here shown as extending over a surface, on a bottom side <NUM> of said first substrate <NUM>.

The second substrate <NUM> is illustrated at a distance from the first substrate <NUM>, the fluid channel <NUM> of the first substrate is in fluid communication with a first metallised via <NUM> and a second metallised via <NUM> formed in the second substrate <NUM>, thereby extending the fluid path through the first metallised via <NUM> and the second metallised via <NUM>.

The sensor comprising a first electrode and a second electrode is arranged on the second substrate <NUM> in fluid communication with the fluid channel <NUM> of the first substrate <NUM>. The first electrode is in electric contact with the first metallised via <NUM> and the second electrode is in electric contact with the second metallised via <NUM>.

The fluid channel <NUM> on the backside of the first substrate <NUM> is shown in the figure. At least one fluid channel port on the backside of the first substrate <NUM> is connected between the fluid path through the first substrate to at least one fluid channel <NUM>, thereby fluidly connecting the at least one capillary bores with the fluid channel <NUM>. The at least one fluid channel <NUM> may for example be a network of interconnected channels. The fluid channel <NUM> may have a width that is larger than the depth of the fluid channel <NUM>.

<FIG> is a schematic perspective view of a cross section of a sensor assembly <NUM> with a plurality of microneedles showing the fluid path of the sensor assembly. The sensor assembly <NUM> is having a first substrate <NUM>, a second substrate <NUM> and a sensor.

The first substrate <NUM> has a plurality of capillary bores <NUM>, here shown through a plurality of microneedles, defining a fluid path extending through said first substrate <NUM> from a top side <NUM> to a fluid channel <NUM> on a bottom side of said first substrate <NUM>. In the present figure, the cross section of the fluid channel <NUM> can be seen.

The second substrate <NUM> and the sensor is arranged according to the previously presented figures.

The sensor assembly may also have a frame structure dimensioned to support the tip of a finger constructed as structure protruding along the longitudinal direction of the microneedles, and preferably having a diameter of less than <NUM>.

The sensor assembly may in some examples be at least partly surrounded by a frame structure dimensioned to support the tip of a finger. Thereby the skin of the tip of the finger may be supported and tensioned to facilitate penetration of the at least one microneedle into the skin.

The sensor assembly may also be protected by a surrounding structure protruding to at least the same plane as the tip of the needles enabling for instance handling of wafers in the case of MEMS manufacturing of the herein described chipset.

The sensor assembly may also have a surrounding structure that stretches the skin prior to penetration by the above mentioned plurality of needles.

An example of a surrounding frame structure <NUM> on the top side of the first substrate <NUM> is also illustrated in <FIG>.

<FIG> is a cross-sectional view of a schematic sensor assembly <NUM> with a microneedle <NUM>. The sensor assembly <NUM> is having a first substrate <NUM>, a second substrate <NUM> and a sensor <NUM>.

The first substrate <NUM> has a capillary bore <NUM> defining a fluid path <NUM> extending through said first substrate <NUM> from the microneedle <NUM> on the top side <NUM> to a fluid channel <NUM> on a bottom side <NUM> of said first substrate <NUM>.

The second substrate <NUM> and the sensor <NUM> are arranged according to the previously presented figures. At least by this, the fluid path <NUM> extends through the microneedle <NUM>, the fluid channel <NUM> and the metallised vias <NUM>, <NUM>. Thereby a fluid in the fluid path <NUM> may pass the sensor <NUM> while passing the first substrate <NUM> and the second substrate <NUM>.

The microneedle <NUM> may have a sharp tip defined by crystallographic planes. For example, the microneedle may have a bevel slope that for each needle or needles is defined by the <NUM> planes.

Each microneedle <NUM> may comprise a capillary bore <NUM>, e.g. a single capillary bore. Thereby bodily fluid may be extracted by means of capillary suction through the microneedle <NUM>.

The microneedle <NUM> may be provided with a cap at a distal end for shielding the capillary bore from clogging, whereby at least one opening to the capillary bore is provided in a lateral direction of the microneedle, perpendicular to the axial or longitudinal extension of the microneedle.

The capillary bore of each microneedle may be provided with a hydrophilic surface. Thereby capillary flow of bodily fluid may be assisted.

The microneedle may comprise a plurality of cutting elements extending along a longitudinal direction of the microneedle. Thereby the skin may be cut and opened to facilitate extraction of bodily fluid.

The perimeter of the bore hole in each microneedle as projected on the bevel of the needle may be located at a distance from the tip in a way where the tip is outside the perimeter.

The microneedle <NUM> may have a length of <NUM>-<NUM>, preferably <NUM>-<NUM>, more preferably <NUM>-<NUM>, and an outer circumference of <NUM>-<NUM>. By this, the microneedle <NUM> has dimensions suitable for penetration of the skin and extraction of bodily fluid.

A portion of the bore hole as projected on the side that contains the capillary system may be outside the connecting capillary generating a maximized wall surface that minimizes surface tension.

The connection between the bore hole and the capillary may for example be designed with a minimized contact angle, thereby enabling a tension driven flow.

The shaft of each needle may be provided both with or without a hilt.

The vertical bore holes may be filled with material that is selective and specific to certain molecules and thereby creating an integrated extraction and sensing chipset. The filler material could for instance be glucose oxidase and carbon powder and thereby creating a glucose specific extraction and sensing chipset.

A plurality of openings may be provided in a lateral direction, around a circumference of the microneedle <NUM>. The at least one opening may be provided about midways along a longitudinal extension of the microneedle <NUM>. Thereby the extraction of bodily fluid is facilitated and the risk for clogging is further reduced.

The bores may with their hollow structure constitute inlets for sampling of bodily fluid. Thereby bodily fluid, such as interstitial fluid (ISF) may be extracted and introduced into the sensor <NUM> with minimal discomfort for the patient.

The sensor <NUM> may have a collecting network of capillaries in different patterns and as an advantage is collection of liquid and storage made without evaporation problems. Hence, the chip can sample and the analysis can also be made ex situ.

The sensor <NUM> may have an interface between the vertical bore holes and the collecting capillary laterally misaligned to allow liquid to wet the walls and hence by capillary action fill the collecting channels on the backside.

The microneedle <NUM> may have the bevel oriented in the crystallographic directions or preferred in the same direction.

<FIG> is a cross-sectional view along the longitudinal axis of a microneedle <NUM> according to an embodiment. In this figure a circular cross-section of the capillary bore <NUM> is shown.

<FIG> is a cross-sectional view along the longitudinal axis of a microneedle <NUM> according to an embodiment. In this figure an uneven cross-section of the capillary bore <NUM> is shown. The microneedle <NUM> shown has two rounded corners. Other designs are also possible, such as one or three rounded corners. The corners may have the same or different radiuses of curvature. In addition, the corners may be cut in such a way that the triangle may be described as having six corners, with three sides that are considerably larger than the other three sides.

<FIG> is a cross-sectional view along the longitudinal axis of a microneedle <NUM> according to an embodiment. In this figure a triangular cross-section of the capillary bore <NUM> is shown.

In this application a triangular cross-section of should encompass a shape with three edges connected with corresponding corners. The edges may be straight, curved, convex or concave.

The corners may be sharp, blunt or rounded with different or the same radius. Thus, within this application a cross-section with the shape of an egg or a heart is considered to be triangular. This reasoning applies both to the shape of the bore as to the shape of the microneedle.

For example a triangular shape of the capillary bore <NUM> may be substantially triangular with a convex base connected to straight sections via a curved corner. This shape of the capillary bore has been demonstrated to be very efficient for extracting interstitial fluid from a finger of a human test subject.

For example, the cross-sectional area of the capillary bore in the distal end may be larger than the cross-sectional area of the capillary bore in the proximal end. In addition, the fluid channel may further comprise a decreasing cross-sectional area in order to further enhance a fluid flow in the fluid channel. The cross sectional area of the capillary bore of the microneedles may for example gradually decrease from the distal end towards the proximal end along the longitudinal direction.

<FIG> is a schematic bottom view of a chip having a sensor assembly according to an embodiment of the present invention. Shown is a first substrate <NUM> and a second substrate <NUM>. The second substrate <NUM> has a first metallised via <NUM> and a second metallised via <NUM>. The metalized vias may be used to communicate readings from a sensor on the opposing side of the second substrate <NUM> and is in electric contact with extended pads. The extended pads may be used to further simplify reading from the sensor.

<FIG> is a top view of the second substrate <NUM> with vias and a sensor. The view is in perspective, hence there may be some distortion present in the figure.

On the second substrate <NUM> a first metallised via <NUM> and a second metallised via <NUM> is formed. The second substrate further comprise a sensor having a first electrode <NUM> and a second electrode <NUM>, both can be seen in the figure as spirals. The first electrode <NUM> is in electric contact with the first metallised via <NUM> and the second electrode <NUM> is in electric contact with the second metallised via <NUM>. By this, readings from the electrodes may be communicated through the second substrate <NUM> by the first metallised via <NUM> and the second metallised via <NUM>.

The sensor assembly may also be provided with a plurality of needles organized in an array or matrix at a minimum distance from each other of <NUM> micrometres but not greater than <NUM> apart, has a sharp tip in the same plane or slightly below a surrounding structure and where the tip may have a <NUM> degree bevel and the needle a hollow bore with a capillary dimension that allows extraction without clogging and a shaft, longer than <NUM> micrometres.

<FIG> is a schematic cross section view of a schematic sensor assembly having multiple bores <NUM> from a plurality of microneedles <NUM>. The sensor assembly <NUM> is having a first substrate <NUM>, a second substrate <NUM>.

The first substrate <NUM> has multiple capillary bores (<NUM>) defining a fluid path <NUM> extending through the first substrate <NUM> from the plurality of microneedles <NUM> on the top side <NUM> to a fluid channel <NUM> on a bottom side <NUM> of said first substrate <NUM>. The figure is illustrated with capillary bores in two of the plurality of microneedles <NUM>, it is however understood that there may be capillary bores in several of the plurality of microneedles <NUM> and that each of the capillary bores may be connected with the fluid channel <NUM>.

Each capillary bore may extend from top side <NUM> of the first substrate <NUM> to a fluid channel port on the bottom side <NUM> of the first substrate <NUM>. Should the sensor assembly be provided with microneedles, the capillary bore may extend from the tip of the microneedles to a fluid channel port on the bottom side <NUM> of the first substrate <NUM>.

The second substrate <NUM> comprise a sensor <NUM> that is arranged according to the previously presented figures. At least by this, the fluid path <NUM> extends through the plurality of microneedles <NUM>, the fluid channel <NUM> and the metallised vias <NUM>, <NUM>. Thereby a fluid in the fluid path <NUM> may pass the sensor <NUM> while passing the first substrate <NUM> and the second substrate <NUM>.

The microneedles <NUM> may for example be located at minimum distance from each other of <NUM> microns in order to avoid the effect of bed of nails.

The microneedles <NUM> may be oriented in a way that enables connection between at least a subset of microneedles using integrated, for instance etched, capillaries.

The microneedles <NUM> may all be combined with a capillary system enabling a capillary flow to a fluid exit port.

The second substrate may be wafer bonded or attached to the first substrate by other means, but may also be connected through capillary tubing or an equivalent flow system.

The sensor may also be configured for detecting a level of glucose in bodily fluid, i.e. a glucose sensor. Thereby a sensor for rapid and accurate detection of the level of glucose in bodily fluid may be provided.

The sensor may be configured for detecting a concentration or presence of lactate, carbon dioxide, or other molecules in bodily fluid. Thereby a sensor for rapid and accurate detection of the level of above mentioned molecule or other molecules, ions or biomarkers in bodily fluid may be provided.

Claim 1:
A sensor assembly (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>) for sampling of a bodily fluid, comprising:
a first substrate (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) comprising at least one capillary bore (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) defining a fluid path (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>) extending through said first substrate from a top side (<NUM>, <NUM>, <NUM>, <NUM>) to a fluid channel (<NUM>, <NUM>, <NUM>, <NUM>) on a bottom side (<NUM>, <NUM>, <NUM>, <NUM>) of said first substrate;
a second substrate (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) arranged in connection with the first substrate, the fluid channel of the first substrate is in fluid communication with a first metallised via (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) and a second metallised via (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) formed in the second substrate, thereby extending the fluid path through the first metallised via and the second metallised via;
a sensor (<NUM>, <NUM>, <NUM>, <NUM>) comprising a first electrode (<NUM>, <NUM>) and a second electrode (<NUM>, <NUM>) arranged on the second substrate in fluid communication with the fluid channel of the first substrate; wherein the first electrode is in electric contact with the first metallised via and wherein the second electrode is in electric contact with the second metallised via.