Device for acquiring sweat of subject and method for manufacturing such device

Abstract

The invention relates to a device (100) configured to acquire sweat from a perspiration body and to be attached to an electronic component, the device comprising a multilayer structure (9) having a contact surface (1) configured to be placed in contact with the body, the structure (9) comprising a microfluidic channel (5) connecting a fluid inlet (3) to a fluid outlet (19), and at least one pair of electrical conductors (27a, 27b), each conductor (27a, 27b) of the pair of conductors (27a, 27b) comprises, at a first end, an electrode (23a, 23b) having a surface area extending along a wall of the microfluidic channel (5) and, at a second end, a connection portion (25a, 25b) accessible via a surface (22a, 22b) adjacent to the contact surface (1) or a surface (17) opposite the contact surface (1) and configured to be electrically coupled to an electronic device.

Description

Technical Field

[0001] The present invention relates to a device configured to acquire sweat from a perspiration body and to be attached to an electronic device, and a method for manufacturing the device. Background Art

[0002] Devices are known in the art whose purpose is to provide measurements related to perspiration of a perspiring subject. Perspiration is a ubiquitous biological thermoregulatory mechanism in mammals, during which fluid is secreted by glands and expelled through small pores in the skin. Parameters of this biological phenomenon can provide useful medical indications of the condition, health and environment of the perspiring subject in question.

[0003] Thus, it may be desirable to obtain information about the volume flow rate of perspiration of the subject, about the temperature of the sweat liquid, or about the composition of the sweat liquid, such as the concentration of urea, lactate, or minerals such as sodium chloride (NaCl), etc. This information may be useful for medical purposes, for example by evaluating the data during long-term monitoring, as well as in real time, for example in the context of physical exercise and / or when the subject is subjected to elevated temperatures.

[0004] In particular, during physical exercise, real-time monitoring of sweat parameters of a perspiring subject can provide more precise information about the subject's state and enable adjustment of effort or environment. For example, monitoring sweat parameters can be used to obtain optimized hydration instructions to achieve desired physical performance.

[0005] Therefore, in order to acquire the sweat of a perspiring subject, various devices have been proposed that aim to obtain one of the above-mentioned measurements. These devices generally include at least one acquisition device and at least one acquisition measurement and analysis device. The acquisition device includes a contact surface configured to be placed in contact with the subject so as to be able to perform an acquisition operation on the parameters of the liquid secreted by one or more pores of the skin of the perspiring subject. The measurement and analysis device is connected to the acquisition device through an interface so as to measure the acquisition information and process and analyze the measurement information so as to subsequently transmit it, for example, to a user. Summary of the invention

[0006] Problem that the invention aims to solve

[0007] In the context of physical exercise, the device used to acquire sweat is subject to a high risk of physical degradation. For example, the device may be exposed to a large number of sudden movements and shaking, and may also be subject to vibrations, shocks or be exposed to precipitation or be contaminated by the elements (dust, mud, etc.). Therefore, the device must have both a good level of resistance to external influences and a sufficient level of accuracy, as well as being comfortable to use.

[0008] Solutions for solving problems

[0009] In view of the above, the object of the present invention is to provide a device for obtaining sweat, which is manufactured in a simultaneously reliable, compact and economical manner. In particular, the object of the present invention is to obtain a device for obtaining sweat, which is consumable, that is to say can be replaced in a low-cost manner after physical exercise.

[0010] This object is achieved by a device configured to capture sweat from a perspiration subject and attached to an electronic device. The device comprises a multilayer structure having a contact surface configured to be placed in contact with the subject, the structure comprising an internal microfluidic channel extending through the structure and fluidically connecting at least one fluid inlet to at least one fluid outlet. The inlet is located at the contact surface and is configured to interface with a surface of the subject comprising at least one pore, and the outlet is located at another surface different from the contact surface.

[0011] The structure further comprises at least one pair of electrical conductors, in particular copper conductors, each of the pair of conductors comprising at a first end an electrode having a surface area (S) extending along a wall of the microfluidic channel, and comprising at a second end a connection portion accessible via a surface adjacent to the contact surface or a surface opposite to the contact surface and configured to be electrically coupled to an electronic device. For example, one or more openings may be configured in the surface adjacent to the contact surface or the surface opposite to the contact surface to receive a connection element from the electronic device.

[0012] Embodiments of such a device having an inlet of a microfluidic channel enable the introduction of sweat in liquid form into the microfluidic channel which directs a laminar flow of the liquid along an electrode to an outlet by capillary forces. Inclusion of such microfluidic channels and electrical conductors in a multilayer structure enables the device to be manufactured by microfabrication techniques (e.g., reel-to-reel processes) that benefit from significant economies of scale. Thus, the device can be manufactured in a manner that is sufficiently affordable to be used in a consumable manner during physical exercise.

[0013] Furthermore, the configuration in which the connection of the conductor is accessible via a surface adjacent to or opposite to the contact surface of the multilayer structure enables attachment to an electronic device configured to measure the resistance and / or conductance between the electrodes without obstructing the contact surface. Thus, simple operation and comfort of the device are maintained.

[0014] In one embodiment, a microfluidic channel may extend in a straight line from a fluid inlet to a fluid outlet of the structure.

[0015] Therefore, the amount of sweat entering the microfluidic channel accesses the outlet through a straight path, and the liquid can contact one or more pairs of electrodes more quickly and be ejected through the outlet more quickly. Therefore, the risk of clogging can be reduced, and the device, especially the device that guides liquid through the microfluidic channel, can be made more reliable.

[0016] In one embodiment, the contact surface may comprise at least one groove for directing sweat to the fluid inlet.

[0017] The groove can be used to guide the sweat flowing through the additional small holes to the fluid inlet of the device. Therefore, the amount of liquid received by the device can be larger and the information obtained is more complete.

[0018] In one embodiment, the corresponding electrodes of a pair of conductors may extend along the same one wall of the microfluidic channel.

[0019] This configuration is simple to manufacture by micromachining methods, for example roll-to-roll type methods, because the electrical conductors can be arranged in the same plane. Therefore, this configuration can only require an embodiment using a layer of conductive material (for example copper).

[0020] In an alternative embodiment, respective electrodes of a pair of conductors may extend along opposing walls of the microfluidic channel.

[0021] In this configuration, two walls of the channel can be provided with electrodes. The electrodes can be opposite each other and thus use less sweat volume, especially compared to a configuration where the electrodes are juxtaposed in the same plane. This enables more accurate measurements.

[0022] In one embodiment, the multilayer structure may have a parallelepiped shape, in particular a flat cuboid shape.

[0023] The parallelepiped shape allows for easy and secure fixing at the four corners. The flat shape also ensures comfort for the user when the device is in contact with the skin.

[0024] In one embodiment, the ratio between the distance separating the electrodes (L) and the surface area of ​​the electrodes (S) may be between 0.01 m^-1 and 0.1 m^-1, in particular between 0.03 m^-1 and 0.05 m^-1.

[0025] According to the inventors' findings, within this range, the ratio between the conductivity of sweat and its molar concentration of sodium chloride is linear. Thus, a particularly simple and precise measurement of the proportion of sodium chloride in sweat can be obtained.

[0026] In one embodiment, the multilayer structure of the device may include a base layer, an intermediate layer and a cover layer. The base layer may include a contact surface configured to be placed in contact with the body. The intermediate layer may be placed between the base layer and the cover layer.

[0027] In one embodiment, the microfluidic channel may be provided in the intermediate layer.The intermediate layer may be deposited directly on a surface of the base layer opposite to said contact surface of the base layer.

[0028] In one embodiment, at least one electrode, in particular each electrode of a pair of conductors, can be deposited directly on the surface of the base layer opposite to the contact surface of the base layer. This configuration of electrodes deposited on the base layer in the microfluidic channel makes it possible to provide a more compact device, since it can reduce the number of layers necessary to form the device. In addition, this configuration makes it possible to reduce manufacturing costs, since the deposition of electrodes and conductors on the base layer can be obtained with micromachining techniques of the "roll-to-roll processing" type. The reduction in the manufacturing costs of the multilayer structure is particularly advantageous for the manufacture of consumable devices, which can be replaced by the user after each use, in particular for hygienic reasons.

[0029] In one embodiment, in a cross section of the device along the thickness of the multilayer structure, the microfluidic channel may extend in the intermediate layer from the base layer to the cover layer. Thus, the microfluidic channel may have a height equal to the thickness of the intermediate layer.

[0030] In one embodiment, the device may be characterized in that the multilayer structure comprises only three layers. Thus, the device is simple to manufacture, which reduces its cost. Furthermore, since it comprises only three layers, a compact device is obtained, which is particularly advantageous for portable devices. The user can thereby obtain a device with a small volume.

[0031] In one embodiment, the device may be characterized by having no electronic components. Thus, the device may be manufactured at a lower cost, which is more conducive to producing a single-use device or a consumable device.

[0032] The object of the present invention is also achieved by a sweat measuring facility, which includes a microfluidic device according to one of the above-mentioned embodiments and an electronic device, the microfluidic device is attached to the electronic device, the connecting parts of at least one pair of conductors of the microfluidic device are electrically connected to the electronic device, and the electronic device is configured to measure the conductance and / or resistance between the electrodes of the device.

[0033] This sweat measuring arrangement has the advantage that separate electronic components of the acquisition device for electrical measurement and signal conversion are in direct contact with the user's skin.

[0034] In one embodiment of the device, the device may include a watch that is attached to the electronic device and is configured to be worn around the user's wrist. In particular, the wristband may be configured so that the contact surface of the device configured to obtain sweat is configured along the surface of the user's skin.

[0035] Such mounting of the measuring device makes it possible to avoid discomfort in motion during physical exercise, as well as enabling direct visual access to the facility and comfortable use like a watch.

[0036] In one embodiment, the electronic device may include a transmission device configured to transmit measurement information and / or receive instructions.

[0037] Thus, the measurement information of the electronic device can be received, processed, analyzed and recorded by a third party device which is not exposed to external influences in the user's immediate environment during physical exercise.

[0038] The object of the present invention is also achieved by a method for manufacturing a device configured to acquire sweat of a perspiring subject according to any one of the above-mentioned embodiments.

[0039] The method comprises the following steps: providing a base layer and manufacturing at least one pair of electrical conductors on the base layer, each conductor comprising an electrode at a first end and a connection portion at a second end; providing an additional layer comprising at least one cut-out region forming a microfluidic channel; and assembling the base layer and the at least one additional layer, in particular by co-lamination, such that the electrodes are arranged in the cut-out region.

[0040] The method makes it possible to obtain economically and quickly a device having the above-mentioned characteristics and advantages.

[0041] In one embodiment, the method may comprise the additional step of closing the microfluidic channel with a further additional layer, in particular by co-lamination.

[0042] In one embodiment, the method may comprise the additional step of producing through holes in the base layer forming the inlets to the microfluidic channels.

[0043] In one embodiment of the method, the cut-away region forming the microfluidic channel may include an access point to a through hole forming an inlet.

[0044] In one embodiment, step a) of the method according to the present invention may further include the following steps:

[0045] i) providing a base layer,

[0046] ii) covering the base layer with a copper layer,

[0047] iii) coating a photosensitive resin layer at least on the copper layer,

[0048] iv) selectively exposing the photosensitive resin to a light beam, in particular an ultraviolet light beam, in order to define the path of the conductor,

[0049] v) dissolving the unexposed photosensitive resin, and

[0050] vi) Chemically etching the copper layer in order to obtain a base-conductor composite.

[0051] The method may be implemented on a large scale and therefore be sufficiently cost effective to provide a device for capturing consumable sweat.

[0052] In another embodiment, step a) of the method according to the present invention may comprise the following steps:

[0053] i) providing a base layer, and

[0054] ii) Printing conductors on the base layer.

[0055] In one embodiment, the method may further include the additional steps of:

[0056] x) Plating the conductors, in particular the electrodes, with at least one metal, preferably a metal selected from nickel, gold, silver and palladium, or with a metal alloy, preferably a metal alloy comprising at least one metal selected from nickel, gold, silver and palladium.

[0057] This plating, also called metallization, makes it possible to obtain electrodes and / or connections with lower contact resistance and higher corrosion resistance. The method implementing this step thus makes it possible to obtain a device for acquiring sweat that provides more reliable and more precise measurement information.

[0058] In one embodiment, the plating of step x) can be performed using a nickel layer covered with a gold layer. The properties of this plating are particularly advantageous.

[0059] In one embodiment, step x) may be performed after step vi). BRIEF DESCRIPTION OF THE DRAWINGS

[0060] The objects, features and advantages of the present invention as set forth above will be more fully understood and appreciated through a study of the following more detailed description of the present invention and the accompanying drawings.

[0061] Figure 1 A sweat measuring arrangement according to one embodiment of the present invention is shown, comprising means for acquiring sweat.

[0062] Figure 2A Shows Figure 1A three-dimensional view of the device, with the microfluidic channel partially open.

[0063] Figure 2B Shows Figure 1 A perspective view of a device with the electrical conductors highlighted.

[0064] Figure 3A Shows Figure 1 The device is along Figure 2A The cross section of the section axis AA.

[0065] Figure 3B Shows Figure 1 The device is along Figure 2A The cross section of the cross section axis BB.

[0066] Figure 3C Shows Figure 1 The device is along Figure 2A Sectional section of the cross-sectional axis CC.

[0067] Figure 4A A cross section of a device for acquiring sweat according to a second embodiment of the present invention is shown.

[0068] Figure 4B A cross section of a device for acquiring sweat according to a second embodiment of the present invention is shown.

[0069] Figure 5 The sequential steps of a method for producing a device according to one embodiment of the invention are schematically shown.

[0070] To make the drawings easier to read, the elements shown are not necessarily to scale, neither to scale relative to each other nor in terms of their relative Cartesian sizes. DETAILED DESCRIPTION

[0071] Figure 1 A sweat measuring device according to one embodiment of the present invention is shown. The device 1000 comprises a device 100 for acquiring sweat and an electronic device 200. In this embodiment, the device 100 has the shape of a flat cuboid, having length and width dimensions of the same order of magnitude in two Cartesian directions x, y, and having a height dimension in a third Cartesian direction z that is much smaller than the length and / or width dimensions, for example at least 5 times smaller.

[0072] In other embodiments, it is also conceivable to provide a device 100 for acquiring sweat, which has a cross section in the xy plane that is triangular, hexagonal, octagonal, and / or has rounded or chamfered corners.

[0073] exist Figure 1In the embodiment, the electronic device 200 also basically has the shape of a flat rectangular parallelepiped, having length and width dimensions of the same order of magnitude in two Cartesian directions x, y, and having a height dimension in the third Cartesian direction z that is much smaller than the length and / or width dimensions, for example, at least 5 times smaller.

[0074] The size of the electronic device 200 is larger than the size of the device one by one, in particular, 10% to 30% larger, so that the device 100 can be received in the opening of the space dug in the electronic device 200, such as Figure 1 shown.

[0075] exist Figure 1 In the view of FIG. 1 , the device 100 is received in the space dug in the electronic device 200 and is connected by means of attachment. Figure 1 The device 100 is attached thereto by a form fit (not shown) such as snap fit means or adhesive bonding. In this position, the device 100 is electrically coupled to the electronic device 200.

[0076] The device 1000 also includes two parts 300a, 300b of the watch, respectively attached at two thin opposite parts of the electronic device 200. Therefore, the device 1000 can be comfortably worn on the user's limbs, such as on the wrist or ankle. The two parts 300a, 300b of the watch are configured so that the contact surface 1 of the device 100 received in the excavated space is configured along the surface of the user's skin. That is, the device 100 is facing downward with reference to the user's field of vision.

[0077] The electronic device 200 comprises a transmission device (not shown) for transmitting measurement information related to the electrical connection and / or for receiving instructions. The housing of the electronic device 200 is made of a rigid and lightweight material.

[0078] The device 100 has a contact surface 1 configured to be placed in contact with a perspiration body. The surface 1 is flat, and when the device 100 is attached to the electronic device 200, the surface 1 slightly protrudes from the electronic device 200 in the direction z. That is, the device 100 slightly exceeds the height of the device 200 from the excavated space of the device 200, in particular, exceeds 1% to 10%. Therefore, when the device 1000 is worn by a user, the device 100 contacts the skin of the user's perspiration body.

[0079] The surface 1 also has a fluid inlet 3 leading to a microfluidic channel 5 (which is located at Figure 2A ), the inlet 3 is located in the center of the surface 1. The contact surface 1 also has a pattern of multiple grooves 7. The pattern is centered on the inlet 3, and each groove 7 of the pattern is connected to the inlet 3. The pattern of grooves 7 makes it possible to guide a large amount of sweat to the fluid inlet 3 more effectively.

[0080] Reference below Figure 2A , Figure 2B and FIG. 3A to FIG. 3C Describe in more detail Figure 1 The structure and operation of the device 100 of FIG. 1000 will be described in particular, that the device 100 does not include electronic components, such as chips. Therefore, in the measuring facility 1000, the electronic components for electrical measurement and signal conversion are offset from the acquisition device 100, which is in direct contact with the user's skin, toward the electronic device 200. Due to the transmission device included in the electronic device 200, the processing, analysis and storage of the measured data can be performed by a third-party facility without being exposed to external influences in the user's immediate environment during physical exercise. At the same time, the facility 1000 including the electronic device 200 is flexible and comfortable to wear, and is simple to manufacture.

[0081] Figure 2A 1 is a perspective view of a device 100 for obtaining sweat. For the purpose of illustration and understanding, Figure 2A The view in FIG. 1 is partially cut along the microfluidic channel 5 in order to identify the path of the microfluidic channel 5 inside the device 100 .

[0082] The device 100 has a multilayer structure 9, which includes a base layer 11, an intermediate layer 13 and a cover layer 15. Preferably, the layers 11, 13, 15 are thin material layers, for example, selected from polyethylene terephthalate (PET), glass-epoxy resin composite film, polyimide (PI), polyethylene (PE), polyethylene naphthalate (PEN), adhesive or paper. The layers 11, 13, 15 can be the same or different material layers from each other. In particular, in one embodiment, the layer 13 can be an adhesive material layer, such as a pressure-sensitive adhesive PSA, to hold the layers 11 and 15 together. The base layer 11 is Figure 2A The base layer 11 has a contact surface 1 on a hidden face not visible in the figure and includes an inlet 3 leading to the microfluidic channel 5. The cover layer 15 has an external connection surface 17. Each of these layers has a thickness between 20 μm and 200 μm, preferably, the base layer 11 is thicker than the intermediate layer 13, and the layer 13 is thicker than the cover layer 15. For example, the base layer 11 can have a thickness of 120 μm, the intermediate layer 13 can have a thickness of 50 μm, and the cover layer 15 can have a thickness of 20 μm.

[0083] The multilayer structure 9 comprises a microfluidic channel 5 extending inside the structure 9 in the xy plane. In particular, the channel 5 is located at the intermediate layer 13, between the base layer 11 and the cover layer 15, and extends linearly, that is, in a straight line from the inlet 3 to the center of the parallelepiped of the device 100 to the fluid outlet 19 of the channel. The channel 5 can have a thickness of 20 μm to 200 μm and a width of 200 μm to 5 mm in the xy plane. The outlet 19 is arranged at a corner 21 a of the parallelepiped of the device 100, at the intersection of two surfaces 22 a, 22 b adjacent to the contact surface 1. The channel 5 has a surface 29 (which is opposite to the contact surface 1) corresponding to the base layer 11. Figure 3B and Figure 3C 17 ), corresponding to the surface 31 of the cover layer 15 opposite to the external connection surface 17 (which is visible in Figure 3B and Figure 3C The upper wall of a portion of the intermediate layer 13 (visible in FIG. 1 ), and two opposite side walls inside the intermediate layer 13.

[0084] Figure 2A Also shown are two electrodes 23a, 23b, which are arranged in the microfluidic channel 5 in such a way as to extend along the side walls of said channel 5. Furthermore, two connection portions 25a, 25b are configured in the structure 9 in such a way as to be accessible via the external connection surface 17. For example, one or more openings may be configured in the external connection surface 17 to receive connection elements from the electronic device 200. The electrodes 23a, 23b correspond to respective first ends and the portions 25a, 25b correspond to respective second ends of two electrical conductors 27a, 27b, which will be referred to in detail in the accompanying drawings. Figure 2B Describe in more detail.

[0085] The external connection surface 17 and the contact surface 1 correspond to opposite operating surfaces of the parallelepiped of the device 100. While the contact surface 1 is configured to come into contact with the skin of the perspiration subject, the external connection surface 17 is in contact with the electronic device 200 (see Figure 1 ) so that the connecting parts 25a, 25b contact the electronic components of the electronic device 200 and establish electrical connection.

[0086] The device 100 according to this embodiment comprises a microfluidic channel 5 connecting the inlet 3 to the outlet 19. Without departing from the spirit of the present invention, alternative embodiments with several inlets leading to the channel 5 and / or several outlets for the liquid to escape from the channel 5 can be considered. Likewise, it is possible to consider configuring several microfluidic channels in the device 100, for example four channels respectively connected to the four inlets and respectively extending toward the four corners of the parallelepiped of the device 100, each channel being provided with a pair of electrodes and a connection portion.

[0087] Figure 2B A view of the base-conductor complex of the device 100 is shown, that is to say without the intermediate layer 13 and without the cover layer 15, so that the path of the conductors 27a, 27b is highlighted. The electrical conductors 27a, 27b are arranged on a surface 29 opposite to the contact surface 1 of the base layer 11 of the multilayer structure 9 (which is Figure 3B and Figure 3C The conductors 27a, 27b are made of a conductive material, preferably copper (Cu), and include electrodes 23a, 23b at their respective first ends and connecting portions 25a, 25b at their respective second ends. In particular, the conductors 27a, 27b are made of the same copper layer formed on the base layer 11, which has been chemically etched to obtain the desired shape.

[0088] The connection portions 25a, 25b are exposed portions of the conductors 27a, 27b. For example, the layers 13 and 15 are open at the connection portions 25a, 25b to enable connection with the electronic device 200 (see FIG. 1 ) through the outer surface 17. Figure 1 ). Thus, electrical contact with the electronic device 200 can be established. The electrodes 23a, 23b are extensions of the conductors 27a, 27b arranged along the wall of the microfluidic channel 5.

[0089] In order to improve their functionality, the electrodes 23a, 23b and the connecting parts 25a, 25b of the conductors 27a, 27b are plated or metallized with at least one metal or metal alloy, which is preferably selected from nickel, gold, silver and palladium. In a preferred embodiment, the electrodes 23a, 23b are plated with a nickel layer of 10nm to 10μm, which in turn is covered with a gold layer of 10nm to 10μm. In an alternative embodiment, the electrodes 23a, 23b are plated with a nickel layer covered with a silver layer, or a nickel layer covered with a palladium layer, or a nickel layer covered with a gold layer, which itself is covered with a palladium layer. Therefore, the contact resistance can be reduced and / or the corrosion resistance can be improved.

[0090] The connection portions 25a, 25b are arranged at one end of the conductors 27a, 27b so as to be accessible through the outer surface 17 of the multilayer structure 9, enabling simple attachment to the electronic device 200 (see Figure 1 ) to measure the resistance and / or conductance between the electrodes without obstructing the contact surface 1. Thus, the operation and comfort of the device are maintained.

[0091] Figure 2B It is also shown that the fluid inlet 3 in the center of the parallelepiped of the device 100 corresponds in this embodiment to a cylindrical perforation which passes through the thickness of the base layer 11 in the direction z, that is to say through the height.

[0092] Thus, a certain amount of sweat received by the fluid inlet 3 is brought into the microfluidic channel 5 and guided along the channel 5 by capillary forces, and then escapes through the outlet 19. When the sweat passes between the electrodes 23a, 23b, the resistance and / or conductance between the terminals of the electrodes can be measured. The conductivity σ of the sweat is calculated from the resistance R or conductance G and the ratio between the surface area S of the electrodes 23a, 23b and the distance L separating the electrodes 23a, 23b (called the S / L ratio). From the conductivity σ of the liquid, the molar concentration C_NaCl in sodium chloride can be approximated empirically.

[0093] The S / L ratio of the electrodes 23a, 23b arranged in the channel is predetermined and known. In this embodiment, the S / L ratio is between 0.01m^-1 and 0.1m^-1, in particular between 0.03m^-1 and 0.05m^-1. Preferably, the ratio is close to 4 / 100, that is, 0.04m^-1. In the scope of intensive studies by the inventors, it has been determined that the relationship between the conductivity σ and the sodium chloride concentration C_NaCl is advantageously linear and deterministic within this range.

[0094] Figure 3A , Figure 3B and Figure 3C The device 100 is shown as follows: Figure 2A The sections of the respective cross-sectional axes AA, BB and CC are shown.

[0095] The three sections are along Figure 2A The axis A and the xz plane are centered on the microfluidic channel 5. The section 3A along the axis AA is centered on the inlet 3 leading to the microfluidic channel 5. The inlet 3 is a central perforation through the base layer 11. When the perforation of the base layer 11 also passes through the intermediate layer 13, the cover layer 15 is not perforated.

[0096] Figure 3B and Figure 3C Also shown are two electrodes 23a, 23b arranged on the same surface 29. The surface 29 is opposite to the contact surface 1 of the base layer 11 of the multilayer structure 9. The electrodes 23a, 23b are arranged separated by a distance L. Therefore, the electrodes 23a, 23b are arranged at the intermediate layer 13 in the same plane xz. The cover layer 15 covers the intermediate layer 13 and provides an additional wall for the microfluidic channel 5, closing the channel 5. Therefore, this embodiment is economical because it is easy to manufacture by micromachining methods.

[0097] In an alternative embodiment, it is conceivable to arrange the two electrodes 23 a , 23 b on the cover layer 15 on the same surface of the wall of the microfluidic channel 5 , for example on the surface 31 opposite the external connection surface 17 .

[0098] The structure of the device 100 described above enables manufacture by micromachining techniques, in particular by roll-to-roll methods, and thus benefits from significant economies of scale. Thus, the device can be manufactured sufficiently economically to be used in a consumable manner during physical exercise.

[0099] Furthermore, configuring the connection 25a, 25b at one end of the conductor 27a, 27b so as to be accessible via the surface 17 opposite to the contact surface 1 of the multilayer structure 9 enables attachment to the electronic device 200 without obstructing the contact surface. Thus, simple handling and comfort of the device are maintained.

[0100] In accordance with Figures 1 to 3C In an embodiment, the device 100 is provided with a pair of electrical conductors 27a, 27b with corresponding electrodes 23a, 23b. In an alternative embodiment, several pairs of electrodes, for example three pairs, may be arranged in sequence along the same microfluidic channel. By arranging several pairs of electrodes in a row, a measurement time difference may be established when a certain amount of sweat successively passes through the pairs of electrodes. The time difference may, for example, be used to determine, approximate or derive a liquid flow velocity and / or a liquid volume flow rate.

[0101] Figure 4A and Figure 4B A device 100' of another embodiment of the invention is shown. Only features that differ from the device 100 are described, which features can be considered equivalent to those described above in relation to the device 100.

[0102] The device 100' further comprises two electrodes 23a' and 23b'. They are not arranged on the same wall of the microfluidic channel 5' corresponding to the channel 5 of the device 100, but are arranged on two opposite walls. In particular, they are arranged on opposite surfaces 29 and 31 of the device 100. Alternatively, it is also conceivable to arrange the electrodes on the two side walls of the channel 5'. Therefore, the trace amount of sweat enclosed between the two electrodes 23a', 23b' is less than, for example, the trace amount of sweat between the electrodes 23a, 23b. This enables more accurate measurement.

[0103] One embodiment of a method for manufacturing a device according to the present invention is described below, which is configured to acquire sweat from a perspiration body and is attached to an electronic device, such as device 100. The method includes a first step of manufacturing at least one pair of electrical conductors on a base layer, each conductor including an electrode at a first end and a connection at a second end.

[0104] Figure 5 The successive steps of a method for performing a first step by photolithography are schematically shown.

[0105] In particular, the method starts with a step A of providing a base layer M11. For example, the base layer M11 can be the base layer 11. Preferably, the layer M11 is a layer of a material selected from polyethylene terephthalate (PET), a glass-epoxy composite film, polyimide (PI), polyethylene (PE), polyethylene naphthalate (PEN) or paper. The layer M11 is preferably thin, in particular having a thickness between 20 μm and 200 μm.

[0106] The base layer M11 is covered with a copper (Cu) layer M12 having a thickness between 1 μm and 100 μm, preferably between 12 μm and 70 μm in step B. Alternatively, a "copper-clad" type material can be used, in which the copper layer M12 is attached to the base layer M11 by vacuum deposition, by thermal assembly or by assembly with an adhesive. In step C, through holes M3 are made in the base layer M11. In this embodiment, the base layer M11 covered with the copper layer M12 is mechanically perforated at the desired position, thereby forming a hole M3 forming an entrance to the microfluidic channel. For example, the hole M3 can form a fluid inlet 3 that passes through the base layer 11 coated with copper.

[0107] Then, in step D, a layer of photosensitive resin M14 is applied onto the base layer M11 coated with copper M12 at least on the copper side, alternatively on both sides.

[0108] In step E, the photosensitive resin M14 is selectively polymerized. In this step, referred to as the irradiation step, some parts of the applied photosensitive resin are exposed to a beam of light M16, in particular an ultraviolet beam, defining polymerized areas M14a and non-polymerized areas M14b on the copper side of the base layer M11. The polymerized areas M14a represent the desired paths of the electrical conductors formed by the copper layer M12 on the base layer M11. For example, conductors 27a, 27b are defined on layer 11, as shown in FIG. Figure 2B The resin M14 located above the portion of the copper layer M12 that is not necessary for forming the electrical conductor is not irradiated, that is to say is not exposed to the light beam, and is therefore non-polymerized M14b.

[0109] In step F, referred to as a development step, the portions of the photosensitive resin layer M14 that were not irradiated and therefore not polymerized and not cross-linked are dissolved, so that polymerized areas M14a of the resin M14 remain.

[0110] In step G, the copper layer M12 is chemically etched. In this step, the polymerized M14a photosensitive resin M14a remaining on the copper M12 selectively protects part of the copper from etching. Therefore, only the copper not protected by the photosensitive resin M12 is etched. Thus, an electrical conductor circuit portion is obtained on the base layer. Thus, a base-conductor composite M18 is formed, for example Figure 2B The base-conductor complex shown.

[0111] In step H, the base-conductor composite M18 is chemically stripped in order to remove the exposed, i.e. polymerized, parts of the photosensitive resin from the base layer M11 and the copper M12 forming the conductor circuit. This makes it possible in particular to release the surface of the copper layer M12 and obtain the conductors M27a, M27b. For example, the conductors 27a, 27b are obtained on the base layer 11.

[0112] In step I, performed after the etching and stripping steps, the electrical conductors M27a, M27b are plated with at least one metal or metal alloy, selected, for example, from nickel, gold, silver and palladium. Preferably, the electrical conductors M27a, M27b are plated with a nickel layer covered with a gold layer. Optionally, only certain parts of the conductors, such as the electrodes 23a, 23b and the connecting parts 25a, 25b, are plated.

[0113] In another embodiment of the manufacturing method, the first step of the method is not performed by photolithography, but by an additive printing method. Printing can be performed by screen printing with conductive ink. Alternatively, printing can be performed by inkjet. In this embodiment, the electrical conductors are printed on the provided base layer. Each conductor is printed on the base layer in a manner that includes at least one electrode and at least one connection.

[0114] For example, the conductors 27a, 27b are printed on the base layer 11. Alternatively, the conductor 27a is printed on the base layer 11 and the conductor 27b is printed on another base layer, for example the cover layer 15. The two layers thus printed can then be assembled, for example, by an adhesive intermediate layer, such as the intermediate layer 13. As described below, the conductors 27a, 27b can be obtained by cutting the intermediate layer. Figure 4A , Figure 4B Device 100'.

[0115] In another example, conductors 27a, 27b are both etched on the base layer 11. Alternatively, conductor 27a is etched on the base layer 11, while conductor 27b is etched on another base layer, such as the cover layer 15. The two layers thus produced can thus be assembled, for example, by an adhesive intermediate layer, such as the intermediate layer 13. As described below, the intermediate layer can be obtained by cutting Figure 4A , Figure 4B Device 100'.

[0116] Method Figure 5 In a second step, not shown, an additional layer is provided comprising at least one cut-out region forming a microfluidic channel. The at least one additional layer is cut out so as to define a microfluidic channel, thereby forming at least one microfluidic channel of the device.

[0117] Optionally, at least one additional layer may also be sectioned to define an access point at the second end of the electrical conductor. Furthermore, the sectioned region forming the microfluidic channel comprises an access point to the through hole forming the inlet of step C.

[0118] For example, the intermediate layer 13 may be sectioned to form the microfluidic channel 5 and cover the base layer 11 and include an access point to the fluid inlet 3. In particular, the microfluidic channel defined in the additional layer, such as in the intermediate layer 13, extends from a perforated location, such as the inlet 3, to a circumferential end of the additional layer, such as the outlet 19.

[0119] In the third step of the manufacturing method, the base-conductor composite including the base layer obtained in step I is assembled with the additional layer by co-lamination so that the electrodes are arranged in the cut-out region. For example, the intermediate layer 13 is laminated on Figure 2B On a base-conductor composite including a base layer 11 and conductors 27a, 27b.

[0120] In the fourth step of the manufacturing method, the microfluidic channel is closed with another additional layer by co-lamination. For example, the cover layer 15 closes the microfluidic channel, which is cut and defined in the intermediate layer 13 and assembled with the base-conductor complex including the base layer 11 and the electrical conductors 27a, 27b. In one example, the cover layer 15 is perforated and then selectively laminated on the intermediate layer 13 to define access openings to the connections 25a, 25b. The cutting and co-lamination can advantageously be performed online on a converting machine.

[0121] In an alternative embodiment, one of the additional layers may also correspond to a product obtained by one of the above methods, for example corresponding to a product obtained from step H or step I. For example, the cover layer 15 may be a base-conductor composite comprising an electrical conductor 27a'. In this embodiment, the additional layer and the first base-conductor composite comprising the base layer 11 and the conductor 27b' may be bonded by another additional adhesive layer, for example an intermediate layer 13, which is cut into the desired pattern of microfluidic channels. This embodiment may be implemented, for example, to obtain a substrate composed of Figure 4A and Figure 4BIn another example, the covering layer 15 may be a base-conductor composite including electrical conductors 27a" and 27b". In this embodiment not shown, the covering layer 15 and the base layer 11 may be bonded due to another additional adhesive layer, such as an intermediate layer 13, which is cut into the pattern of the desired microfluidic channels. In this embodiment, the connections 25a", 25b" may be located on the external connection surface 17 and the electrodes 23a", 23b" are located on the opposite surface of the layer 15. Thus, metallized holes or through-holes are used to electrically connect the connections 25a", 25b" and the electrodes 23a", 23b".

[0122] The additional layers may be layers of materials that are the same or different from each other and the same or different from the material of the base layer. In particular, in a preferred embodiment, the additional layer may be a layer of adhesive material to keep the base layer and another additional layer superimposed. For example, the material of the intermediate layer 13 is different from the material of the base layer 11 and the cover layer 15.

[0123] The described method enables an apparatus having the features and advantages of the apparatus 100 to be obtained in an affordable and rapid manner. In particular, the method can be implemented on a large scale, for example in a roll-to-roll process, and enables sufficient cost efficiency to be obtained to provide a consumable and replaceable apparatus for acquiring sweat.

[0124] Description of Reference Numerals

[0125] 1 Contact surface of the device

[0126] 3 Inlet to the microfluidic channel

[0127] 5 Microfluidic channels

[0128] 7 Grooves in contact surfaces

[0129] 9 Multilayer structure

[0130] 11. Base layer

[0131] 13. Middle Layer

[0132] 15 Covering

[0133] 17 External connection surface

[0134] 19 Microfluidic channel outlet

[0135] 21 Corner of the device

[0136] 22a, 22b Surfaces adjacent to the contact surface

[0137] 23a, 23b Electrode at the first end of the conductor

[0138] 25a, 25b The connection portion at the second end of the conductor

[0139] 27a, 27b Electrical conductor

[0140] 29 The surface of the base layer opposite to the contact surface

[0141] 31 Surface of the covering layer opposite to the external connection surface

[0142] 100, 100' Device for obtaining sweat

[0143] 200 Electronic devices

[0144] 300a, 300b Parts of watches

[0145] 1000 Device for measuring sweat

[0146] M3 Through hole according to manufacturing method

[0147] M11 Base layer according to manufacturing method

[0148] M12 Copper layer according to manufacturing method

[0149] M14 Photosensitive resin layer according to manufacturing method

[0150] M14a Resin polymerization area according to manufacturing method

[0151] M14b Unpolymerized area of ​​the resin according to the manufacturing method

[0152] M16 Beam according to manufacturing method

[0153] M18 Base-conductor complex according to manufacturing method

[0154] M27a, M27b Electrical conductor according to the manufacturing method

Claims

1. A device (100, 100') configured to acquire sweat from a perspiration subject and attached to an electronic device (200), the device comprising: a multilayer structure (9) having a contact surface (1) configured to be placed in contact with the body, The multilayer structure (9) comprises an internal microfluidic channel (5) extending through the multilayer structure (9) and fluidically connecting at least one fluid inlet (3) to at least one fluid outlet (19), The inlet (3) is located at the contact surface (1), and the outlet (19) is located at another surface (22a, 22b) different from the contact surface (1), and At least one pair of electrical conductors (27a, 27b), each conductor (27a, 27b) comprising: an electrode (23a, 23b) at a first end, the electrode having a surface area (S) extending along a wall of the microfluidic channel (5); and A connection (25a, 25b) at the second end, the connection (25a, 25b) being accessible via an adjacent surface (22a, 22b) or a surface (17) opposite the contact surface (1) and being configured to be electrically coupled to the electronic device (200).

2. The device according to claim 1, wherein the microfluidic channel (5) extends in a straight line from the fluid inlet (3) to the fluid outlet (19) of the multilayer structure (9).

3. Device according to claim 1 or 2, wherein the contact surface (1) comprises at least one groove (7) for guiding sweat to the fluid inlet (3).

4. A device according to any one of claims 1 to 3, wherein the corresponding electrodes (23a, 23b) of a pair of the conductors (27a, 27b) extend along the same wall of the microfluidic channel (5).

5. A device according to any one of claims 1 to 3, wherein the corresponding electrodes (23a, 23b) of a pair of the conductors (27a, 27b) extend along opposite walls of the microfluidic channel (5).

6. The device according to any one of claims 1 to 5, wherein the structure (9) has a parallelepiped shape, in particular a flat cuboid shape.

7. A device according to any one of claims 1 to 6, wherein the ratio (S / L) between the distance (L) separating the electrodes (23a, 23b) and the surface area (S) of the electrodes (23a, 23b) is between 0.01m^-1 and 0.1m^-1, in particular between 0.03m^-1 and 0.05m^-1.

8. The device according to any one of claims 1 to 7, wherein the multilayer structure (9) comprises a base layer (11), an intermediate layer (13) and a cover layer (15), The base layer (11) comprises a contact surface (1) configured to be placed in contact with the body, and The intermediate layer (13) is arranged between the base layer (11) and the cover layer (15).

9. The device according to claim 8, wherein the microfluidic channel (5) is arranged in the intermediate layer (13).

10. The device according to any one of claims 1 to 9, characterized in that The multilayer structure (9) comprises only three layers.

11. The device according to any one of claims 1 to 10, characterized in that No electronic components.

12. A sweat measurement installation (1000) comprising a device (100, 100') according to any one of claims 1 to 11 and an electronic device (200), The device (100, 100') is attached to the electronic device (200), the connecting parts (25a, 25b) of at least one pair of conductors (27a, 27b) of the device (100, 100') are electrically connected to the electronic device (200), and the electronic device (200) is configured to measure the conductance and / or resistance between the electrodes (23a, 23b) of the device.

13. A method for manufacturing a device (100, 100') according to any one of claims 1 to 11, the method comprising the following steps: (a.) providing a base layer (11) and manufacturing at least one pair of electrical conductors (27a, 27b) on the base layer (11), each conductor (27a, 27b) comprising an electrode (23a, 23b) at a first end and a connection portion (25a, 25b) at a second end, (b.) providing an additional layer (13, 15) comprising at least one cut-out region forming a microfluidic channel, and (c.) Assembling the base layer (11) and at least one of the additional layers (13, 15) such that the electrodes (23a, 23b) are arranged in the cut-out regions, the assembling being carried out in particular by co-lamination.

14. The method according to claim 13, comprising the additional step of: (d.) Closing the microfluidic channel (5) with a further additional layer (15), in particular by co-lamination.

15. The method according to claim 13 or 14, comprising the additional step of: (e.) Producing through holes (M3) in the base layer forming the inlets (3) leading to the microfluidic channels (5).

16. The method of claim 14, the cut-out region forming the microfluidic channel (5) comprising an access point to a through hole (M3) forming the inlet (3).

17. The method according to any one of claims 13 to 15, wherein step (a.) comprises the following steps: i) providing a base layer (M11), ii) covering said base layer (M11) with a copper layer (M12), iii) coating a photosensitive resin layer (M14) at least on the copper layer (M12), iv) selectively exposing the photosensitive resin (M14) to a light beam (M16), in particular an ultraviolet light beam, in order to define the path of the conductors (M27a, M27b), v) dissolving the unexposed photosensitive resin (M14b), and vi) Chemically etching the copper layer (M12) so as to obtain a base-conductor composite (M18).

18. The method according to any one of claims 13 to 15, wherein step (a.) comprises the following steps: i) providing a base layer (11), and ii) Printing the conductors (27a, 27b) on the base layer (11).

19. The method according to any one of claims 13 to 16, comprising the additional step of: x) coating the conductors (27a, 27b), in particular the electrodes (23a, 23b), with at least one metal, in particular a metal selected from nickel, gold, silver and palladium, or with a metal alloy, in particular a metal alloy comprising at least one metal selected from nickel, gold, silver and palladium.

20. The method according to claim 19, wherein the plating in step x) is performed using a nickel layer covered with a gold layer.

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