FR3138989A1 - Skin treatment device - Google Patents

Abstract

Device (1) for treating a user's skin by iontophoresis and/or electrostimulation intended to be applied to the user's skin, the device (1) comprising a support layer comprising at least one support film and comprising an electrode main electrode, a counter electrode and a current generator electrically connected to the main electrode on the one hand and to the counter electrode on the other hand, in which the current generator comprises a plurality of galvanic couples connected in series, each galvanic couple being formed of a first conducting pole forming a cathode and a second conducting pole forming anode, and in which the galvanic couples are adjacent in pairs and electrically connected in pairs, the first conducting pole of one of the galvanic couples being electrically connected to the second conductive pole of an adjacent galvanic couple. Figure for abstract: Fig. 1.

Description

Skin treatment device FIELD OF THE INVENTION

The present invention relates to the field of skin treatment. More specifically, the present invention relates to a device for skin treatment, in particular by iontophoresis and/or electroporation and/or electrostimulation, preferably non-therapeutic.

STATE OF THE ART

Iontophoresis, electroporation or electrostimulation allow the skin to be treated using electric currents. Skin treatment devices such as facial care masks designed to deliver an electric current to a user's face are known. However, the effectiveness of these devices remains improvable, in particular because the current they generate is too low. These devices sometimes include a polymer support matrix on which current generators are arranged. The effectiveness of these masks is limited in particular due to short circuits that can appear between the current generators and the matrix and/or between the current generators and the skin. The electric currents are therefore not correctly delivered to the user's skin, whether in terms of intensity and/or location. Treatment by iontophoresis and/or electrostimulation is therefore not optimal, and the effectiveness of the known devices is disappointing.

One aim of the invention is to improve the operation of devices for treating the skin by iontophoresis or electrostimulation, in particular to improve their effectiveness.

Another aim of the invention is to make the use of skin treatment devices by iontophoresis or electrostimulation easier and more accessible to everyone.

Another aim of the invention is to improve the storage and durability of devices for treating the skin by iontophoresis or electrostimulation.

Another aim of the invention is to provide a skin treatment device which is particularly ergonomic and intuitive to use.

Another object of the invention is to provide a skin treatment device which is particularly safe, painless and reliable.

According to a first aspect, a device for treating the skin of a user by iontophoresis and/or electrostimulation is proposed, intended to be applied to the skin of the user, the device comprising a support layer comprising at least one support film and comprising a main electrode, a counter-electrode and a current generator electrically connected to the main electrode on the one hand and to the counter-electrode on the other hand, in which the current generator comprises a plurality of galvanic couples connected in series, each galvanic couple being formed of a first conductive pole forming a cathode and a second conductive pole forming anode, and in which the galvanic couples are adjacent two by two and electrically connected two by two, the first conductive pole of one of the galvanic couples being electrically connected to the second conductive pole of an adjacent galvanic couple. In other words, the device comprises at least two galvanic couples connected in series, via an electrical connection between the first conductive pole of one of the galvanic couples and the second conductive pole of an adjacent galvanic couple. Such a series arrangement makes it possible to accumulate the voltages generated by each of the galvanic couples, and therefore the intensity that the device is capable of providing (at equivalent skin resistance), which makes it possible to remarkably increase the efficiency of the device which is the subject of the invention.

According to advantageous and non-limiting characteristics, taken alone or in any combination:

- the plurality of galvanic couples connected in series comprises a first galvanic couple and a last galvanic couple, the first conductive pole of the first galvanic couple being electrically connected to the main electrode and the second conductive pole of the last galvanic couple being electrically connected to the counter electrode, or the second conductive pole of the first galvanic couple being electrically connected to the main electrode and the first conductive pole of the last galvanic couple being electrically connected to the counter electrode;

• the main electrode and the counter electrode are made of silver and/or silver chloride, each first conductive pole forming a cathode comprising silver and/or silver chloride and each second conductive pole forming anode comprising zinc;
• two adjacent galvanic couples are electrically connected via carbon connectors;
• a carbon connector extends below a second conductive pole;
• the carbon connector comprises a portion extending below at least 80% of the surface of the second conductive pole;
• two adjacent galvanic couples are electrically connected by direct contact between the first conductive pole of one galvanic couple and the second conductive pole of the adjacent galvanic couple;
• wherein the main electrode is electrically connected to a first conductive pole via a carbon connector and the counter electrode is electrically connected to a second conductive pole via a carbon connector made of silver and/or silver chloride;
• the support layer comprises at least three galvanic couples, preferably at least four galvanic couples;
• for each galvanic couple, the first conductive pole and the second conductive pole are separated from each other by a free space;
• the first conductive pole of a galvanic couple and the second conductive pole of a galvanic couple are separated by a distance of between 0.5 mm and 5 mm, preferably between 1 mm and 3 mm, for example equal to 2 mm;
• the device comprises an impregnation layer comprising at least one impregnation film, the impregnation layer covering at least the main electrode, the counter-electrode and the current generator, device in which the parts of the impregnation layer arranged above the free spaces are intended to be covered with an electrically conductive activation product;
• the device comprises a stencil layer covering the impregnation layer and comprising at least one stencil film, the stencil layer comprising at least one permeable zone adapted to allow an electrically conductive activation product to pass only at the level of at least one predefined zone of the impregnation layer, called the free zone, the free zone being intended to be covered with the activation product;
• the current generator comprises at least two current generation assemblies comprising a plurality of galvanic couples connected in series, the two current generation assemblies being connected in parallel.

According to a second aspect, there is provided a method of manufacturing a device described above, comprising a step of:
a) formation of the support layer by printing from inks, preferably by screen printing, of at least one printed assembly comprising a main electrode, a counter-electrode and a current generator on the at least one support film.

According to advantageous and non-limiting characteristics, taken alone or in any combination:

• step a) comprises a step of: a1) printing carbon connectors intended to electrically connect galvanic couples of a current generator and at least one of the main electrode and the counter-electrode to one of a first conductive pole and a second conductive pole of a current generator;
• step a) includes a step of:
  a2) zinc printing for each galvanic couple of one of the first conductive pole and the second conductive pole;
  a3) printing in silver and/or silver chloride for each galvanic couple of the other among the first conductive pole and the second conductive pole and printing in silver and/or silver chloride of the main electrode and the counter electrode.

DESCRIPTION OF FIGURES

Other features and advantages of the present invention will become apparent upon reading the following description of a preferred embodiment. This description will be given with reference to the appended figures, including:

• there illustrates a drop-shaped skin treatment device;
• there illustrates a circular shaped skin treatment device;
• there illustrates a support layer of a drop-shaped skin treatment device;
• there illustrates a support layer of a circular skin treatment device;
• there illustrates a support layer of a triangular-shaped skin treatment device;
• there schematically illustrates the operation of the device, in a cross-sectional view, when applied to a user's skin;
• there schematizes an enlarged view of a portion of a support layer of a device, in a cross-sectional view;
• there illustrates a current generator of a device according to a first embodiment;
• there illustrates a current generator of a device according to a second embodiment;
• there illustrates a current generator of a device according to a third embodiment;
• there illustrates the support layer of the covered with a layer of impregnation of a device;
• there represents the steps of a method of using the device;
• there represents the steps of a manufacturing process of the device;
• there represents the support layer of the following a first step in the support layer manufacturing process;
• there represents the support layer of the following a second step in the support layer manufacturing process;
• there represents the layer of the following a third step in the support layer manufacturing process.

DETAILED DESCRIPTION OF THE INVENTION Device

In reference to the , according to a first aspect, there is proposed a device 1 for treating the skin of a user by iontophoresis and/or electrostimulation. The device 1 is intended to be applied to the skin of the user, in particular and preferably on the face. The device 1 could be applied to any dermal part of the user's body. However, as will be detailed later, the invention proposes different forms of device which are remarkably well adapted for particular areas of the face which are often the subject of a desire for treatment by users. The device 1 advantageously allows a cosmetic treatment of the skin, for example by activating a cosmetic substance and/or by optimizing and/or improving its effectiveness. Different methods can be envisaged for doing this, typically the generation of microcurrents, for example iontophoresis and/or electroporation. By activation, optimization and/or improvement of the effectiveness of a cosmetic substance, it is understood that at least one active agent contained in the cosmetic substance is likely to be activated or to see its effectiveness optimized and/or improved by the device 1, in order to increase the effectiveness of the cosmetic treatment of the skin.

The device 1 is adapted to be activated, i.e. placed in operating conditions, by an activation product that is electrically conductive. In other words, the generation of electric currents is triggered by the application of a product to at least certain areas of the device 1. The device 1 is therefore inactive in the absence of the activation product, and only becomes active when the activation product is in contact with at least one predefined area, as will be detailed later. This makes it possible to control the moment of activation of the product, and in particular to match this moment to the actual use of the device 1 by the user. Thus, during the storage (or transport) phase of the device 1, the latter is not activated, thus preserving its service life, and in particular the service life of the current generator, as will be detailed later.

The activation product may comprise an active agent for skin treatment. This active agent allows a cosmetic treatment of the skin, preferably non-therapeutic, the effectiveness of which is increased by the device 1, thanks to the current that it generates, as will be detailed later. Preferably, said active agent is ionized at the pH of the activation product, for example between 4 and 10, and substantially equal to 7, in order to obtain an electromigration mechanism.

The device 1 which is the subject of the invention will make it possible to improve the diffusion of the active agent in the skin, thanks to the principle of iontophoresis and/or electrostimulation and/or electroporation. These principles, using electric current to transport an active agent in the skin, are well known to those skilled in the art and will not be detailed in more detail. The activation product may for example comprise a cosmetic product, preferably non-therapeutic, such as a cosmetic cream, a serum, comprising an active agent such as vitamin C, hyaluronic acid, or any other active agent beneficial for the skin and compatible with treatment by iontophoresis and/or electrostimulation and/or electroporation. The activation product may also be a therapeutic product such as a cream for treating burns.

The device 1 may also be used to eliminate or reduce various types of pain or other sensory discomfort, including, but not limited to, back pain, joint pain, neck pain, shoulder pain, tingling or numbness of the skin, muscle pain, muscle cramps, joint stiffness, etc. To this end, the device 1 may then make it possible to improve the diffusion of an analgesic by means of the principles set out above.

With reference to figures 1, 2 and 5, the device 1 can therefore have different shapes depending on the area to which it is designed to be applied. For example, a device 1a intended to be applied to the temple can have a general drop shape. Thus, the contours of the device are rounded and a first portion of the device, when viewed from above, is wider than a second portion of the device. A device 1b intended to be applied to the cheekbone can have a circular shape. Thus, when viewed from above the device forms a disk. A device intended to be applied to the forehead can have a triangular shape, the illustrating a layer 2c of this device. Thus, thanks to the different shapes proposed by the invention, each area of the face traditionally treated by care (cheekbone, forehead, temple) has a device particularly well adapted to the shape of the area in question, which makes it possible to increase the comfort of use, the ergonomics and the effectiveness of the treatment. However, other shapes could be imagined, without departing from the scope of the invention, which would be adapted to other areas of the face or other dermal areas of the body such as for example the tops of the hands, the neckline, etc.

Support layer

With reference to Figures 3 to 5, the device 1 comprises a support layer 2. By support layer is meant any layer serving as a support for other layers, in this case the impregnation and stencil layers which will be detailed later. illustrates the support layer 2a of a drop-shaped device 1a. The illustrates the support layer 2b of a circular device 1b. The illustrates the support layer 2c of a triangular-shaped device.

In reference to the , the support layer 2 comprises at least one support film 21. The support film 21, and consequently, the device 1 which is the subject of the invention, is sufficiently flexible to be able to adapt to the shapes and reliefs of the skin of the area to be treated, and in particular to the cheekbones, temple, and forehead, as explained above. The support film 21 is preferably insulating, that is to say that it does not allow current to pass. This makes it possible to avoid any risk of short circuit within the device, by preventing current from flowing in the support film 21.

The support film 21 is for example made of a flexible plastic such as polyurethane (PU) or polyethylene terephthalate (PET). Preferably, the support film 21 has a thickness greater than or equal to 20 µm, preferably greater than or equal to 40 µm, and less than or equal to 90 µm, for example substantially equal to 50 µm or 80 µm. Indeed, such thicknesses allow the support film 21, and therefore the device 1, to conform well to the area of skin on which it is intended to be placed.

The device 1 may comprise a plurality of support films 21 assembled together, for example by gluing. On the contrary, the support film may be monolithic, that is to say formed from a single film.

The support layer 2 comprises at least one main electrode 22, at least one counter-electrode 23 and at least one current generator 24.

The current generator 24 is electrically connected to the main electrode 22 on the one hand and to the counter-electrode 23 on the other hand, so as to create an electrical potential differential between the latter.

The electrodes 22, 23 are intended to be applied opposite the user's skin and are adapted to allow the circulation of an electric current in the user's skin, when the device 1 is placed in contact with the user's skin. Indeed, the user's skin behaves as a current consumer, in particular as a resistor. The skin of a mammal, in particular human skin, typically behaves as a 10 kΩ resistor. For this purpose, the main electrode 22 and/or the counter electrode 23 is formed at least of one main metal, a good electrical conductor.

The electrodes 22, 23 are intended to be in direct or indirect contact with the skin. By indirect contact, it is meant that an element is arranged between the electrode 22, 23 and the skin such as an activation product, an absorbent layer and/or a fabric, etc.

The device 1 is in a so-called “operating” state when it is applied to the skin of a user and when the current generator 24 is activated so as to generate an electric current. The expression “in operation” will subsequently be used to designate a situation in which the device 1 is in operation, that is to say that it generates a potential differential between the electrodes, then an electric current when the device is applied to the skin.

In operation, the electric current generated by the current generator 24 flows between the electrodes 22, 23 and into the user's skin. As illustrated in , the electric current flows through the current generator 24 to the main electrode 22, then penetrates the user's skin to reach the counter electrode 23. The current can also flow in a direction opposite to that illustrated.

In some cases, the main electrode 22 is called a “treatment electrode”. In other words, advantageously, the main electrode 22 can specifically allow the improvement of the absorption of an activation product when the main electrode 22 covers a portion of the user’s skin to which an activation product containing a particular active agent is applied. In operation, the activation product is thus specifically absorbed by the skin at the main electrode 22, the shape of which can then advantageously be chosen to correspond as precisely as possible with the area to be treated. Thus, the main electrode 22 of the device can advantageously have the same shape as the general shape of the device 1, as defined and explained previously. This makes it possible to position the main electrode 22 as close and as precisely as possible opposite the specific area to be treated (cheekbone, temple, forehead, etc.)

The main electrode 22 may be a cathode or an anode and, correspondingly and inversely, the counter electrode 23 may be an anode or a cathode.

Preferably, the nature of the main electrode 22 (cathode or anode), and therefore of the counter-electrode 23, is adapted according to the type of activation product that it is desired to use in combination with the device 1. In particular, the main electrode 22 will be adapted to be an anode for certain types of activation products such as a vitamin C-based cream while the main electrode 22 will be adapted to be a cathode for certain other types of activation products.

More specifically, the activation product may comprise molecules that are positively or negatively charged at a given pH. If the main electrode 22 has the same polarity as the polarity of the molecules, the molecules are repelled by the main electrode 22 and thus pushed towards the user's skin. For example, vitamin C molecules are negatively charged for a pH between 5 and 7. A device 1 aimed at improving the absorption by the skin of vitamin C molecules present in an activation product will therefore preferably have a main electrode 22 forming an anode.

As can be seen in the various figures, the main electrode 22 preferably comprises carbon, advantageously in the form of a plurality of carbon points, for example arranged under the main metal constituting the main electrode. This makes it possible to give the user a visual indication of the main electrode 22 (or active electrode as explained above) to help him correctly position the latter on the area of the skin that he wishes to treat, without however degrading the electrical conductivity of the main electrode 22.

The counter electrode 23 has a polarity opposite to that of the main electrode 22. The counter electrode 23 is therefore a cathode if the main electrode 22 is an anode and the counter electrode 23 is therefore an anode if the main electrode 22 is a cathode.

The main electrode 22 and the counter electrode 23 are made from conductive materials, typically metals.

The main electrode 22 and the counter electrode 23 preferably comprise silver and/or silver chloride. More preferably, the main electrode 22 and the counter electrode 23 are made of silver and/or silver chloride. Silver and silver chloride have the advantage of being hypoallergenic and of interacting well with the skin. In addition, silver and silver chloride have the advantage of being good conductors of electricity. Silver chloride is less subject to oxidation than silver, so that combined with silver, it helps to limit oxidation and therefore to improve the durability of the electrodes 22, 23.

Preferably, the main electrode 22 and the counter electrode 23 are made of silver and silver chloride. More specifically, the main electrode 22 and the counter electrode 23 are each composed of 55% silver and 45% silver chloride.

Alternatively, the main electrode 22 and/or the counter electrode 23 are made of carbon. Carbon is conductive and not very oxidizable.

Advantageously, the main electrode 22 and the counter electrode 23 are printed on the support film 21 using conductive inks, and preferably metallic inks. In particular, the main electrode 22 and the counter electrode 23 are preferably printed on the support film 21 by screen printing.

The current generator 24 comprises at least one galvanic couple 240. The galvanic couple 240 is formed of a first conductive pole 241 forming a cathode and a second conductive pole 242 forming an anode separated from each other by a free space 243.

The free space 243 is preferably insulating, i.e. it does not allow electric current to pass through it. This can for example be enabled by the fact that the support film 21 is insulating and that the free space 243 consists of an area of the support film 21 on which no material is printed.

Alternatively, an insulating material could be disposed on the support film 21 at the free space 243.

Preferably, the first conductive pole of a galvanic couple and the second conductive pole of a galvanic couple are separated by a distance of between 0.5 mm and 5 mm, preferably between 1 mm and 3 mm, for example equal to 2 mm. In other words, the free space 243 has a length of between 0.5 mm and 5 mm, preferably between 1 mm and 3 mm, for example equal to 2 mm.

The free space 243 is intended to be filled, at the time of activation (of putting into operation) of the device 1, by an electrically conductive activation product to connect together the first conductive pole 241 and the second conductive pole 242 of the same galvanic couple 240.

The first conductive pole 241 and the second conductive pole 242 of the galvanic couple 240 are adapted to, when connected by the activation product, allow the circulation of electrons between them. The electrons are generated by the difference between the standard electrical redox potentials of the first conductive pole 241 and the second conductive pole 242.

A galvanic couple 240 is thus adapted to generate an electric current when the first conductive pole 241 and the second conductive pole 242 are connected so as to allow an oxidation-reduction reaction between said poles. An electrochemical cell is formed.

More specifically, when the first conductive pole 241 and the second conductive pole 242 of the galvanic couple 240 are connected by the activation product, upon contact with the activation product, constituent atoms of the second conductive pole 242 (forming an anode) oxidize and electrons are released. The electrons then flow via the activation product to the second conductive pole 242. As illustrated in , the activation product PA between the first conductive pole 241 and the second conductive pole 242 allows the circulation of electrons and the generation of an electrical circuit.

Thus, in operation, the device 1 is traversed by an electric current without requiring an external battery or any other source of electrical power external to the device 1. This results in a remarkably limited size of the device 1, and remarkable freedom of use (no need for a power outlet, external battery, etc.).

The constituent materials of the first conductive pole 241 and the second conductive pole 242 advantageously comprise conductive materials, typically metals.

The first conductive pole 241 (forming the cathode) advantageously comprises silver and/or silver chloride. Preferably, the first conductive pole 241 is made of silver and/or silver chloride.

The second conductive pole 242 (forming anode) advantageously comprises zinc. Preferably, the second conductive pole 242 is made of zinc. In this case, the zinc is the reducing agent of the chemical oxidation-reduction reaction and the second conductive pole 242 (the zinc ink in this case) will be consumed during use of the device 1.

Thus, advantageously, when the first conductive pole 241 and the second conductive pole 242 are connected by an activation product, the zinc atoms are oxidized and therefore release electrons according to the following reaction: Zn → Zn ²⁺ + 2e ^- .

The electrons will flow from the first conductive pole 241 to the second conductive pole 242. This is made possible by the fact that the standard electrical redox potentials of zinc and silver are different. In this case, the theoretical standard electrical potential of zinc is -0.76 V and that of silver is +0.80 V. Thus, each galvanic couple 240 formed of zinc and silver theoretically makes it possible to obtain a 1.56 V battery.

Galvanic couples 240 may include other materials. For example, these pairs can be formed by: zinc-copper, zinc-copper/copper halide, zinc-copper/copper oxide, magnesium-copper, magnesium-copper/copper halide, zinc-silver, zinc-silver-silver oxide, zinc-silver-silver halide, zinc-silver-silver chloride, zinc-silver-silver bromide, zinc-silver-silver iodide, zinc-silver-silver fluoride, zinc-gold, magnesium-gold, aluminum-gold, magnesium-silver, magnesium-silver oxide, magnesium-silver-silver halide, magnesium-silver-silver chloride, magnesium-silver-silver bromide, magnesium-silver-silver iodide, magnesium-silver-silver fluoride, magnesium-gold, aluminum-copper, aluminum-silver, aluminum-silver oxide, aluminum-silver/silver halide, aluminum-silver/silver chloride, aluminum-silver/silver bromide, aluminum-silver iodide, aluminum-silver fluoride, copper-silver halide, copper-silver chloride, copper-silver bromide, copper-silver iodide, copper-silver fluoride, iron-copper, iron-copper/copper oxide, iron-copper, iron-copper/copper oxide, iron-copper/copper halide, iron-silver, iron-silver/silver oxide, iron-silver/silver halide, iron-silver/silver chloride, iron-silver/silver bromide, iron-silver/silver iodide, iron-silver/silver fluoride, iron-gold, iron-carbon conductive, zinc-carbon conductive, copper-carbon conductive, magnesium-carbon and aluminum-carbon.

The galvanic couples 240 and the couple comprising the main electrode 22 and the counter-electrode 23 may also comprise alloys.

As explained above, the current generator 24 is electrically connected to the main electrode 22 on the one hand and to the counter electrode 23 on the other hand.

More precisely, the main electrode 22 is electrically connected to a first conductive pole 241 of a galvanic couple 240 or to a second conductive pole 242 of a galvanic couple 240.

Depending on the nature of the main electrode 22 (anode or cathode), the main electrode 22 is electrically connected to one or the other of a first conductive pole 241 of a galvanic couple 240 and a second conductive pole 242 of a galvanic couple 240.

For example, if the main electrode 22 is an anode, it will be connected to a second conductive pole 242 since the latter forms an anode. Generally, each of the main electrode 22 and counter electrode 23 is of the same polarity as the first or second conductive pole 241, 242.

The main electrode 22 and the counter-electrode 23 can be connected to a conductive pole 241, 242 of the same galvanic couple 240 or of different galvanic couples 240. In the case where the current generator 24 comprises a single galvanic couple 240, the main electrode 22 and the counter-electrode 23 are connected to a conductive pole 241, 242 of this same galvanic couple 240.

One of the electrodes 22, 23 is electrically connected to a first conductive pole 241 by a first connector 244. The other of the electrodes 22, 23 is electrically connected to a second conductive pole by a last connector 245.

In other words, the first conductive pole 241 connected to an electrode 22, 23 is connected to the electrode 22, 23 via the first connector 244. The second conductive pole 242 connected to an electrode 22, 23 is connected to the electrode 22, 23 via the last connector 245.

The main electrode 22 and the counter electrode 23 can be connected to a conductive pole 241, 242 via connectors 244, 245 advantageously comprising carbon, and preferably made of carbon. A connector 244, 245 comprising carbon, hereinafter referred to as a carbon connector 244, 245, allows the circulation of an electric current.

A carbon connector 244, 245 is advantageously a carbon strip. A carbon connector 244, 245 preferably has a length of less than 5 mm and greater than 1 mm and a width of the order of 2 mm. The length of a carbon connector 244, 245 is preferably less than 5 mm to allow good conductivity of the current, a carbon connector that is too long having a significant resistance. In the case where a connector is required over a longer distance, in particular greater than 5 mm, it will be preferable to use another better conductive material, preferably the material used for the main electrode 22 or the counter-electrode 23.

Preferably, a connector 244, 245 is printed on the support film 21 from a conductive ink comprising carbon, preferably by screen printing. A carbon connector 244, 245 comprises carbon but may additionally comprise other materials, preferably conductive materials.

The main electrode 22 and the counter electrode 23 may be connected to a conductive pole 241, 242 via connectors 244, 245 comprising other electrically conductive materials. For example, a connector 244, 245 may comprise the same material as a material comprised in the main electrode 22 and/or the counter electrode 23.

Alternatively, the main electrode 22 and the counter electrode 23 may be connected to a conductive pole 241, 242 by direct contact between an electrode 22, 23 and a conductive pole 241, 242.

According to a non-illustrated embodiment, the first connector 244 comprises a material identical to a material included in the electrode 22, 23. Preferably, the first conductive pole 241 and the electrode 22, 23 to which the first conductive pole 241 is connected comprise silver and/or silver chloride and the first connector 244 comprises silver and/or silver chloride. Also preferably, the last connector 245 is made of carbon.

According to an embodiment illustrated in , the counter electrode 23 is connected to the first conductive pole 241, the counter electrode 23 and the first conductive pole 241 are made of silver and/or silver chloride, and the first connector 244 that connects the counter electrode 23 and the first conductive pole 241 is made of silver and/or silver chloride. Since the counter electrode 23 and the first conductive pole 241 are made of the same material, they can be continuously connected by a first connector 244 of the same material. Printing of the counter electrode 23, the first conductive pole 241, and the first connector 244 on the support film 21 is thus facilitated and does not require a different material for the first connector 244.

Furthermore, in the embodiment illustrated in , the main electrode 22 is connected to the second conductive pole 242, the electrode 22 is made of silver and/or silver chloride, the second conductive pole 242 is made of zinc and the last connector 245 which connects the electrode 22 and the second conductive pole 242 is made of carbon.

Alternatively, the electrode 22 could be in direct contact with the second conductive pole 242 and there would be no additional connector.

Advantageously, the current generator 24 comprises a plurality of galvanic couples 240. It is then understood that the main electrode 22 is connected to a conductive pole 241, 242 of a galvanic couple 240a different from the galvanic couple 240d of which a conductive pole 241, 242 is connected to the counter-electrode 23. More precisely, a conductive pole 241, 242 of a first galvanic couple 240a is electrically connected to the main electrode 22 and a conductive pole 241, 242 of a last galvanic couple 240d is electrically connected to the counter-electrode 23.

The current generator 24 comprises a plurality of galvanic couples 240 connected in series. The galvanic couples 240 are thus adjacent two by two and are electrically connected two by two. This makes it possible to make a series connection of said plurality of galvanic couples 240, and therefore to increase the voltage potential, as will be detailed later.

Preferably, two adjacent galvanic couples 240 are separated by a distance equal to the distance which separates the two conductive poles 241, 242 of the same galvanic couple 240.

More precisely, two adjacent galvanic couples 240b, 240c are connected by connecting the second conductive pole 242b of one galvanic couple 240b and the first conductive pole 241c of the other galvanic couple 240c.

Advantageously, two adjacent galvanic couples 240 are electrically connected via a couple connector 246 advantageously comprising carbon. Preferably, the couple connector 246 is made of carbon. The couple connectors 246 make it possible to circulate an electric current from one galvanic couple 240 to another adjacent galvanic couple 240. Alternatively, the couple connector 246 may comprise other materials, such as electrically conductive metals. However, as illustrated in the various figures, it will be preferable to use carbon couple connectors 246 for their low cost, their ease of implementation and their harmlessness to the skin.

Preferably, with reference to FIGS. 3 and 7, the torque connector 246 extends below at least one conductive pole 241, 242 that it connects. In other words, the at least one conductive pole 241, 242 partially covers the torque connector 246.

More preferably, the couple connector 246 comprises a portion extending below at least 80% of the surface of a conductive pole 241, 242. Advantageously, the couple connector 246 comprises a portion extending below at least 80% of the surface of a second conductive pole 242. This makes it possible to improve the electrical conductivity between two adjacent galvanic couples 240. Advantageously, each couple connector 246 has, when viewed from above, a p-shape (or symmetrically q-shape), i.e. it has a solid, substantially square area and a tail (or thin area), the solid area extending below the surface of a second conductive pole 242 while the tail is not covered. Such an arrangement makes it possible to optimize the passage of current between two adjacent 240 galvanic couples without impacting the redox reaction, or even by optimizing it.

Indeed, in the case, for example, of a couple connector 246 made of carbon and a second conductive pole 242 made of zinc, the conductivity is improved because carbon is more conductive than zinc. It has been measured that the conductivity could be multiplied by two when the couple connector 246 has a solid area under a conductive pole 241, 242.

According to one embodiment, the solid area of the torque connector 246 corresponds to 100% of the surface of a second conductive pole 242. In the embodiment illustrated in for example, the surface of a second conductive pole 242 is greater than the solid area of the torque connector 246, that is to say that the second conductive pole 242 (in this case the zinc) covers the torque connector 246 (in this case the carbon) and protrudes from said torque connector 246. This makes it possible to ensure that, despite the manufacturing tolerances, the second conductive pole 242 (in this case the zinc) will completely cover the torque connector 246 (in this case the carbon), in particular in order to guarantee a good aesthetic appearance of the device 1.

Alternatively, according to a non-illustrated embodiment, two adjacent galvanic couples 240 are electrically connected by direct contact between the second conductive pole 242 of a galvanic couple 240 and the first conductive pole 241 of an adjacent galvanic couple 240. This makes it possible to achieve the series connection of said plurality of galvanic couples 240, without having to use another material.

Arranging a plurality of galvanic couples 240 in series makes it possible to generate, when the device 1 is in operation, a voltage (measured between the main electrode 2 and the counter-electrode 23) greater than the voltage generated by a single galvanic couple 240. Indeed, the voltages generated by each galvanic couple 240 of a series of galvanic couples 240 are cumulative. For example, theoretically, a zinc-silver galvanic couple 240 generates a voltage of 1.56 V. Consequently, theoretically, a current generator 24 comprising two galvanic couples 240 will generate a voltage of 3.12 V (1.56 V multiplied by 2) and a current generator 24 comprising three galvanic couples 240 will generate a voltage of 4.68 V (1.56 V multiplied by 3). Empirically, it has been measured that a current generator 24 comprising a zinc-silver galvanic couple 240 generates a voltage of 1.1 V. Thus, empirically, a current generator 24 comprising two galvanic couples 240 generates a voltage of 2.2 V (1.1 V multiplied by 2) and a current generator 24 comprising three galvanic couples 240 generates a voltage of 3.3 V (1.1 V multiplied by 3). The current generator 240 of the support layer 2 illustrated in comprises five 240 galvanic couples. Empirically, this 24 current generator generates a voltage of 5.5 V (1.1 multiplied by 5).

Consequently, in operation, the intensity of the electric current generated by the plurality of galvanic couples 240 in series is greater than the electric current generated by a single galvanic couple 240. Indeed, the resistance of the skin (which will consume the current) remaining identical, by increasing the voltage compared to the devices of the prior art, thanks to the series connection of said plurality of galvanic couples 240, the current (principle of Ohm's law) which will flow in the skin is necessarily increased, when the device 1 of the invention is activated and placed on the skin. It is recalled that the skin behaves on average like a resistance of 10 kΩ (10,000 Ω). Thus, theoretically, a current generator 24 comprising a single galvanic couple 240 will generate a current of 110 µA (1.1 V / 10,000 Ω). Similarly, a 24 current generator comprising five 240 galvanic couples will generate a current of 550 µA (5.5 V / 10,000 Ω).

However, due to current losses (e.g. at the contact between the skin and the electrodes 22, 23), the actual current measured is lower than the theoretical current. Thus, for example, the current generator 24 illustrated in comprising a galvanic couple 240 generates a current of an intensity of up to 100 µA. The current generator 24 illustrated in comprising two galvanic couples 240 generates a current of an intensity of up to 150 µA. The current generator 24 of the drop-shaped support layer 2 illustrated in generates a current of up to 300 µA. The current generator 24 of the circular support layer 2 illustrated in generates a current of up to 180 µA.

The performance of the current generator 24 is thus improved. Thus, more current flows in the user's skin, which will increase the treatment by iontophoresis and/or electrostimulation and/or electroporation. The performance and effectiveness of the device 1 are therefore improved. This allows, among other things, to better diffuse an active agent of an activation product in the user's skin.

Advantageously, the current generator 24 comprises at least three galvanic couples 240. Preferably, the current generator 24 comprises at least four galvanic couples 240 as in the examples illustrated in FIGS. 3 to 5.

According to the embodiment illustrated in , the current generator 24 comprises five galvanic couples 240.

According to a certain embodiment illustrated in , the current generator 24 comprises at least two current generation assemblies 247 each comprising a plurality of galvanic couples 240 connected in series and the two current generation assemblies 247 are connected in parallel.

Arranging the current generating sets 247 in parallel makes it possible to accumulate the intensities of the electric currents generated by each current generating set 247. Thus, the intensity of the electric current generated by the current generator 24 is increased. Indeed, the particular arrangement illustrated in for example, allows a current of up to 200 µA to be generated.

Preferably, the elements printed on the support film 21 (electrodes 22, 23, current generator 24 and connectors 244, 245, 246) have a thickness of between 10 µm and 20 µm. The support film 21 has, as already mentioned, a thickness of between 20 µm and 90 µm, or 40 µm and 90 µm. Consequently, the support layer 2 preferably has a thickness of between 30 µm and 110 µm, or between 50 µm and 110 µm. The support layer 2 thus offers a remarkable compromise between electrical conductivity, flexibility, and duration of use (in particular for the zinc ink which is consumed during the treatment as explained above).

Impregnation layer

The device 1 further comprises an impregnation layer 4 comprising at least one impregnation film 41. The impregnation layer 4 covers at least the main electrode 22, the counter-electrode 23 and the current generator 24.

Indeed, to operate the device 1, it is desired that activation product be impregnated at the level of zones 42 of the impregnation layer 4, called “activation zones 42”.

First, it is necessary to activate the current generator 24 and therefore its galvanic couples 240. To do this, the conductive poles 241, 242 of each galvanic couple 240 must be connected together so that a redox reaction takes place, as explained above. This can be implemented by the presence of the activation product at the free spaces 243 between the conductive poles 241, 242 of each galvanic couple 240. Thus, it is desired that activation product be disposed at the free spaces 243 and that activation product remain for a certain operating time of the device 1 at the free spaces 243. The impregnation layer 4 at the current generator 24 plays in particular the role of a reservoir of activation product and thus allows the activation of the galvanic couples 240 of the current generator 24 for a certain period of time. Thus, current is generated for a certain period of time, preferably for the duration necessary for the treatment of the area of the face to be treated. First activation zones 42a therefore correspond to the zones of the impregnation layer 4 arranged at the level of the free spaces 243. By “at the level”, it is understood that first activation zones 42a therefore correspond to the zones of the impregnation layer 4 arranged opposite and/or on and/or above the free spaces 243.

Preferably, each first activation zone 42a extends from the first conductive pole 241 to the second conductive pole 242 of a galvanic couple 240. More preferably, each first activation zone 42a is arranged opposite a portion of a first conductive pole 241, a portion of the free space 243 and a portion of a second conductive pole 242 of a galvanic couple 240. In such a way, when activation product is applied to the first activation zone 42, the first conductive pole 241 and the second conductive pole 242 of each galvanic couple 240 are correctly connected to allow an oxidation-reduction reaction. More precisely, at the time of activation (of putting the device into operation), the activation product will make it possible to bring the first and second conductive poles 241, 242 into electrical contact by filling the free space 243, initially insulating.

According to a certain embodiment, for a galvanic couple 240, a first activation zone 42a comprises a zone of the impregnation layer 4 located opposite (i.e. covering) the entire galvanic couple 240, namely its first conductive pole 241, its second conductive pole 242 and its free space 243.

Preferably, in operation, it is preferable that activation product is also present between each electrode 22, 23 and the user's skin to facilitate the flow of electric current between the device 1 and the skin. This also makes it possible to limit the risk of redness of the skin upon contact with the electrodes 22, 23 and to increase the comfort of use. Furthermore, in the case where the activation product comprises an active agent for treating the skin, it is necessary to apply activation product between the skin and at least one of the electrodes 22, 23, preferably between the main electrode 22 and the skin, to ensure good absorption of the activation product (more precisely of an active ingredient contained in the activation product) at the level of at least one of the electrodes 22, 23 (preferably of the main electrode 22). Therefore, we understand the interest of the impregnation layer 4 at the electrodes 22, 23 which also makes it possible to play the role of reservoir of activation product, more precisely of active agent, for a certain period of time. Thus, a second activation zone 42b corresponds to the zone of the impregnation layer 4 arranged at the main electrode 22, as can be seen in for example. A third activation zone 42c corresponds to the zone of the impregnation layer 4 arranged at the level of the counter-electrode 23.

By “at the level”, it is understood that the third and second activation zones 42b, 42c correspond respectively to the zones of the impregnation layer 4 arranged opposite and/or on and/or above the main electrode 22 and the counter-electrode 23.

Thus, the impregnation film 41 of the impregnation layer 4 has in particular the role of being impregnated with an activation product advantageously comprising an active agent intended to be diffused into the skin by iontophoresis and/or electrostimulation. The impregnation film 41 is therefore manufactured from at least one porous material, that is to say a material which absorbs the activation product.

Preferably, the impregnation film 41 is made from a nonwoven textile, for example nonwoven cotton. A nonwoven textile has the advantage of being absorbent and is generally hypoallergenic so that it can be placed in contact with the skin of a user without risk of skin reaction.

Furthermore, a non-woven textile has the advantage of being very flexible and therefore does not limit the flexibility of the device 1.

The impregnation film 41, and consequently the impregnation layer 4, preferably have a thickness greater than or equal to 100 µm, preferably greater than or equal to 800 µm, and less than or equal to 2 mm. The thickness of the impregnation film 41, and consequently of the impregnation layer 4, will be chosen in particular according to the desired absorption capacity of the impregnation layer 4.

The impregnation film 41 may be made from materials adapted to the viscosity of the activation product. For example, if the activation product is very low in viscosity and therefore very liquid (as would be the case, for example, with a physiological serum or a saline solution), it would be desirable for the impregnation film 41 to be made from a highly absorbent material to prevent, when an activation product is applied to the device 1, the activation product from spreading (by capillarity) in an undesirable manner in the device 1 or from flowing out of the device 1 (for example, onto the ground). Conversely, if the activation product is very viscous (as would be the case, for example, with a cosmetic cream or a gel), it would be desirable for the impregnation film 41 to be made from a low-absorbent material to allow the impregnation film 41 to impregnate sufficiently.

The impregnation layer 4 may comprise a single impregnation film 41 which covers the assembly comprising the main electrode 22, the counter-electrode 23 and the current generator 24. In this case, the impregnation layer 4 is said to be monolithic. For example, this embodiment, particularly simple and easy to implement during the manufacture of the device 1, is well suited in the case where the activation product has a high viscosity (it is therefore pasty, for example in the form of a cosmetic cream). Indeed, in this case, when the activation product is applied to the activation zone 42 (i.e. to all of this zone 42 or to part of this zone 42) of the impregnation layer 4, the activation product remains substantially on this activation zone 42 and does not spread in an undesirable manner to other zones of the impregnation layer 4, in particular to zones which are not activation zones 42.

In this case of a monolithic impregnation layer 4, the latter may comprise at least one capillarity limitation device, such as for example a groove, a throat or even a slot. Such a device makes it possible to cut capillary paths within the impregnation layer 4 and thus to locally limit the diffusion of the activation product within the impregnation layer 4 by capillarity. It is thus possible to control the diffusion of the activation product within this monolithic impregnation layer 4. This makes it possible to envisage the use of a relatively fluid activation product while simplifying the manufacturing process of the device 1. Advantageously, the impregnation layer comprises two capillarity limitation devices, arranged on either side of the current generator 24.

According to another embodiment illustrated in , the impregnation layer 4 comprises a plurality of impregnation films 41. In other words, the impregnation layer 4 is then not monolithic but comprises at least two, preferably three, impregnation films 41 that are distinct and separate from each other. In the example illustrated, the impregnation layer 4 comprises three impregnation films 41, including a first impregnation film 41a intended to cover the main electrode 22, a second impregnation film 41b intended to cover the counter-electrode 23 and a third impregnation film 41c intended to cover the current generator 24. Advantageously, the first, second and third impregnation films 41a, 41b, 41c are not in contact with each other. This embodiment is for example suitable in the case where the activation product has a low viscosity (it is therefore liquid, fluid, for example in the form of serum or solution). Indeed, in this case, when activation product is applied to an activation zone 42 (i.e. to this entire zone 42 or to a part of this zone 42) of the impregnation layer 4, the activation product tends to spread. The fact that the impregnation films 41a, 41b and 41c are not in contact makes it possible to prevent the activation product from spreading undesirably to other zones of the impregnation layer 4, in particular to zones which are not activation zones 42.

In the case where the impregnation layer 4 comprises a plurality of impregnation films 41, the impregnation films 41 are not necessarily made of the same material. However, for reasons of simplicity and cost, three separate but identical films (in the same material) may be used.

It should be noted that different activation products could be used depending on the different activation zones 42. Therefore, the impregnation films 41 could each be made of materials adapted to the viscosity of the activation product they are intended to receive.

Preferably, at least one impregnation film 41 is not pre-impregnated. The pre-impregnation may allow the use of the device 1 by a user without any prior step except applying the device 1 to the skin.

However, pre-impregnation may reduce the operating time of the device 1 for treating the user's skin. For example, this may result in premature activation of the current generator 24 if the corresponding activation area 42a is pre-impregnated. Thus, the current generator 24 and thus the device 1 would have a reduced operating time since the current generator 24 would have already been operating for a certain period of time before the user applies it to his skin.

It is therefore preferred that the impregnation film(s) 41 are not pre-impregnated. Consequently, it is preferred that the user impregnates the activation zones 42 as little time as possible before applying the device 1 to his skin. Indeed, it is particularly advantageous that the first or second conductive pole 244, 245 comprising the reducer (in this case zinc) is not pre-impregnated so as not to trigger the redox reaction before the actual use of the device 1.

As can be seen from the in particular, the impregnation layer 4 has a shape corresponding to the shape of the device 1, and in particular to the drop, disk or triangle shapes described above. More specifically, in the preferred embodiment where the impregnation layer comprises a plurality of impregnation films 41a, 41b, 41c, each of the first, second and third impregnation films 41a, 41b, 41c respectively has the same shape as each of the main electrode 22, counter electrode 23 and current generator 24. More specifically, in the case of the drop-shaped device 1, the first impregnation film 41a has a drop shape, the second impregnation film 41b has a circular arc shape, the third impregnation film has a circular arc shape. In the case of the circular-shaped device 1, the first impregnation film has a disk shape, the second impregnation film has a circular arc shape, the third impregnation film has a circular arc shape. It will thus be understood that the shape of each impregnation film corresponds to the shape of the area that it is intended to impregnate.

Stencil layer

The device 1 comprises a stencil layer 6 at least partially covering the impregnation layer 4. The stencil layer 6 comprises at least one stencil film 61.

The stencil layer 6 comprises at least one permeable zone 62 adapted to allow electrically conductive activation product to pass only at predefined zones of the impregnation layer 4 called “free zones 44”.

Preferably, the stencil layer 6 comprises a plurality of permeable zones 62 and to each permeable zone 62 of the stencil layer 6 corresponds a free zone 44 of the impregnation layer 4. In other words, the free zone 44 of a permeable zone 62 is the zone of the impregnation layer 4 at which the permeable zone 62 is located. By “at the level”, we mean “opposite”, “above” and/or “on”. The free zone 44 has a surface and a shape identical to the permeable zone 62. The permeable zone 62 makes the free zone 44 accessible to an activation product which would be applied to the permeable zone 62.

The stencil layer 6 has the role of allowing the activation of only the activation zones 42, and of protecting the other zones from the activation product. The stencil layer 6 aims to prevent the application of activation product to zones of the impregnation layer 4 which are not activation zones 42. This therefore allows the designers of the devices 1 to determine which zones will or will not be in contact with the activation product, regardless of the user's handling and skills. This results in great simplicity of use of the device 1 and great reliability.

Indeed, it is desired to avoid short circuits within the device 1 as much as possible, to limit the current generator 24 from “emptying” too quickly and to ensure that the current passes fully through the skin (treatment effectiveness). Typically, if an activation product were applied to the entire surface of the impregnation layer 4, and therefore the entire surface of the support layer 2 were in contact with an activation product, many short circuits would occur, the current preferring to pass through the activation product (the “simplest” path) rather than through the skin. It is therefore desired to precisely target the areas of the impregnation layer 4 on which the activation product must be applied to avoid as many short circuits as possible and control and optimize the path of the electric current.

For this, the stencil layer 6 comprises permeable zones 62. The permeable zones 62 allow the circulation of activation product through the stencil layer 6, towards the impregnation layer 4 during an application of activation product on the stencil layer 6. The permeable zones 62 are for example made of a porous material.

The remainder of the stencil layer 6, i.e. the impermeable areas 63, are preferably made of a material which would prevent any circulation of activation product towards the impregnation layer 4 during an application of activation product to the stencil layer 6 at these impermeable areas 63.

Advantageously, as can be seen in the various figures, the permeable zones 62 are openwork zones, preferably formed by holes (or openings or cutouts) made in the stencil film 61. In other words, the permeable zones 62 are empty zones. A stencil film 61 is therefore openwork, i.e. perforated, at the level of a permeable zone 62. In yet other words, the permeable zones 62 reveal the free zones 44 of the impregnation layer 4. The permeable zones 62 are thus, in terms of shape, complementary to the free zones 44.

Each free zone 44 comprises at least one activation zone 42. A free zone 44 typically has a surface area smaller than or identical to that of a corresponding activation zone 42.

The free zones 44 are adapted to allow impregnation with activation product at the activation zones 42. By applying activation product to a permeable zone 62 and therefore at the level of a corresponding free zone 44, it is expected that the activation product impregnates a corresponding activation zone 42. More precisely, the free zone 44 may be smaller than the activation zone 42 in the case of a liquid activation product. Indeed, in this case, it is expected that the activation product having reached the free zone 44 spreads (by capillarity) beyond the free zone 44 and impregnates at least the corresponding activation zone 42. Furthermore, the free zone 44 may have a size substantially identical to that of the activation zone 42 in the case of a viscous activation product, such as for example a gel or a cream for example cosmetic. Indeed, in this case, it is not expected that the activation product having reached the free zone 44 will spread beyond the free zone 44 so that it is preferred that the free zone 44 corresponds substantially to the activation zone 42.

Preferably, at least one free zone 44, called “first free zone 44a”, comprises at least a portion of the first activation zone 42a. In other words, a permeable zone 62, called “first permeable zone 62a”, is located opposite at least a portion of the first activation zone 42a. Thus, at least one first permeable zone 62 is located opposite at least a portion of the free space 243 of a galvanic couple 240.

Advantageously, a first permeable zone 62a, and therefore a corresponding first free zone 44a, is located opposite each free space 243 of the support layer 2. In this way, the stencil layer 6 is provided to allow the activation of each galvanic couple 240.

According to one embodiment, a first permeable zone 62a, and therefore a corresponding first free zone 44a, is only arranged opposite a portion of a free space 243 and the length of the first permeable zone 62 (and therefore also of the first free zone 44a) is less than the length of the free space 243. The surface area of the first permeable zone 62a, and therefore of the first free zone 44a, is thus less than the surface area of the first activation zone 42a. This scenario is suitable, for example, when an activation product is not very viscous and therefore very liquid, such as, for example, a physiological serum or a saline solution. Indeed, in this case it is sufficient to initially apply the activation product to a first free zone 44a corresponding to a small part of the first activation zone 42a because the activation product will spread so as to impregnate at least the first activation zone 42a of the impregnation layer 4.

According to another embodiment illustrated in , a first permeable zone 62a is arranged opposite at least 20% of the total surface area of the first activation zone 42a. The corresponding first free zone 44a therefore has a surface area of at least 20% of the total surface area of the first activation zone 42a. In other words, the first permeable zone 62a, and therefore also the first free zone 44a, is arranged opposite a portion of a galvanic couple 240 which extends from the first conductive pole 241 to the second conductive pole 242. The first permeable zone 62a may also be arranged opposite a portion of a galvanic couple 240 so as to be opposite a portion of a first conductive pole 241, a portion of the free space 243 and a portion of a second conductive pole 242 of a galvanic couple 240. This scenario is suitable, for example, when an activation product is viscous. Indeed, it is in this case necessary to initially apply activation product to the first free zone 44a which has a surface area of at least 20% of the surface area of the first activation zone 42a to impregnate at least the first activation zone 42a of the impregnation layer 4 because the activation product will spread little.

It is thus understood that the dimensioning of the permeable zones 62 of the stencil layer 6 is correlated, in particular, with the viscosity of the activation product. Indeed, the more viscous, pasty, thick the activation product is, as would be the case for example with a cream or a gel, the less it will spread (diffuse) in the impregnation layer 4, so it is appropriate to maximize the size of the permeable zones 62. Conversely, the more liquid, fluid the activation product is, the more it will spread (diffuse) in the impregnation layer 4, in particular by capillarity, so it is appropriate to minimize the size of the permeable zones 62.

In the example illustrated in , the first permeable areas 62a are rectangular in shape. Each first permeable area 62a has a length approximately equal to 7 mm and a width approximately equal to 2 mm. Each first permeable area 62a is designed such that each corresponding first free area 44a is arranged opposite a portion of a first conductive pole 241, a portion of the free space 243 and a portion of a second conductive pole 242 of a galvanic couple 240, each of these portions having an advantageously similar surface.

Advantageously, the stencil layer 6 further comprises permeable zones 62 arranged opposite the main electrode 22 and/or the counter-electrode 23. The impregnation layer 4 therefore comprises corresponding free zones 44.

Preferably, a second permeable zone 62b is arranged opposite the second activation zone 42b which is arranged at the level of the main electrode 22. The impregnation layer 4 therefore comprises at least one second free zone 44b corresponding to the second permeable zone 62b located opposite said second free zone 44b.

Also preferably, a third permeable zone 62c is arranged opposite the third activation zone 42c which is arranged at the level of the counter-electrode 23. The impregnation layer 4 therefore comprises at least a third free zone 44c corresponding to the third permeable zone 62c located opposite said third free zone 44c.

Thus, an activation product can be applied to these permeable zones 62b, 62c such that the activation product impregnates the second free zone 44b and third free zone 44c and, consequently, impregnates the second activation zone 42b and third activation zone 42c to allow the circulation of electric current via the electrodes 22, 23 when the device 1 is applied to the skin of a user.

Preferably, the second permeable zone 62b has a shape similar to that of the main electrode 22. The second free zone 44b therefore has a shape similar to that of the main electrode 22. Also preferably, the third permeable zone 62c has a shape similar to that of the counter-electrode 23. The third free zone 44c therefore has a shape similar to that of the counter-electrode 23.

The stencil layer 6 preferably comprises a stencil film 61. The stencil layer 6 may also comprise a plurality of stencil films 61, each of which may comprise one or more permeable zones 62.

Regardless of the embodiment of the stencil layer 6 detailed above, it is clear that the latter allows the user to apply activation product to the entire device 1, on the stencil layer 6, without having to worry about the areas that need to be activated or not. Indeed, it is the permeable areas 62 and the impermeable areas 63 of the stencil layer 6 that allow the activation product to pass through to the activation area(s) 42 or, on the contrary, prevent the activation product from reaching the other areas. In other words, the stencil layer 6 allows the activation product to be guided to areas previously defined by the designers of the device 1, in this case the activation areas 42.

The stencil layer 6 is preferably adapted to be removed from the device 1 before the application of the device 1 to the skin of a user. Indeed, the stencil layer 6 aims in particular to allow the application of activation product to the free zones 44 of the impregnation layer 4 so as to allow the impregnation of the activation zones 42. Once the user has applied the activation product to the stencil layer 6 and indirectly to the free zones 44 of the impregnation layer 4, the stencil layer 6 can be removed.

This can in particular make it possible to discover the second and third activation zones 42b, 42c. Thus, according to one embodiment, the total surface of the electrodes 22, 23 can be applied in contact with the skin.

Furthermore, this makes it possible to keep on the device 1 only the activation product necessary for the operation of the device 1 and not the activation product which would have been applied to impermeable zones 63. This guarantees that no activation product remains on unwanted zones, which limits the risk of short circuits appearing when using the device 1.

The stencil layer 6 is preferably flexible. The stencil layer 6 is for example made of a flexible plastic such as polyethylene terephthalate (PET). The stencil layer 6 preferably has a thickness of less than 50 µm. The thickness of the stencil layer 6 is typically greater than 30 µm, preferably approximately equal to 40 µm.

Thus, the stencil layer 6 makes it possible, thanks to a remarkable combination of permeable zones 62 and impermeable zones 63 judiciously sized and positioned, to guide (i.e. to let through) the activation product only towards the activation zones 42 comprising, in this case, a part of the free space 243, and preferably, a part of a first conductive pole 241, a part of a second conductive pole 242 of a galvanic couple 240, and advantageously the main electrode 22 and the counter electrode 23; and on the contrary, to preserve the other zones (other than the activation zones 42) from the activation product.

Contact method

Advantageously, the device 1 comprises contact and holding means to ensure contact between the device 1 and the user's skin and to hold the device 1 on the skin despite possible external disturbances (wind, clothing, hair, etc.).

The contact means comprise, for example, an elastic band. For example, in the case of a device 1 taking the form of a face mask, the device 1 may comprise an elastic band which would surround the head to press the device 1 against the face.

Preferably, the contact means comprise an adhesive layer 5. The adhesive layer 5 is preferably arranged between the impregnation layer 4 and the stencil layer 6. The adhesive layer 5 comprises at least one adhesive film 51.

The adhesive layer 5 preferably comprises at least one permeable zone 52 adapted to allow an activation product to pass only at the level of at least one activation zone 42. The permeable zone 52 is preferably perforated, for example by being formed by a hole (or an opening) made in the adhesive film 51.

The adhesive layer 5 preferably has a shape similar to the stencil layer 6.

Preferably, the adhesive layer 5 covers the impregnation layer 4 located on the current generator 24 (except the free zones 44). The adhesive layer 5 is arranged on and in contact with at least a portion of the impregnation layer 4. The adhesive layer 5 does not cover the portions of the impregnation layer 4 located opposite the main electrode 22 and the counter electrode 23, in order to allow good current flow between the electrodes 22 and 23 and the skin.

Thus, the adhesive layer 5 ensures that the device 1 is held on the skin while isolating the galvanic couples 240 from the skin and allowing the activation of each galvanic couple 240 via the free zones 44. The galvanic couples 240 being isolated from the skin by the adhesive layer 5, the risk of short-circuiting within the latter is eliminated and the risk of seeing redness appear on the skin is reduced.

The adhesive layer 5 has an external adhesive surface 53 intended to come into contact with the user's skin and to ensure the attachment of the device 1 to the skin for the entire duration of the treatment.

Advantageously, the stencil layer 6 constitutes a cover for the adhesive layer 5. In other words, when the stencil layer 6 is removed from the device 1, the adhesive external surface 53 of the adhesive layer 5 is uncovered and can then be stuck to the user's skin.

The adhesive layer 5 therefore also remarkably allows the stencil layer 6 to be held on the device 1 before the stencil layer 6 is removed from the device 1. The stencil layer 6 and the adhesive layer 5 therefore play a respective role towards one another: the stencil layer 6 protects the adhesive outer surface 53 of the adhesive layer 5, in particular from dust, thus preserving its adhesive power, while the adhesive outer surface 53 ensures the holding of the stencil layer 6 while waiting for the user to remove it during the actual use of the device 1.

The adhesive layer 5 advantageously also has an internal adhesive surface intended to come into contact with the impregnation layer 4, and thus ensure its attachment to the latter. Preferably, the adhesive layer 5 is then formed by a double-sided adhesive film 51, that is to say a film having an external adhesive surface 53 intended to be in contact with the skin and an internal adhesive surface intended to be in contact with the impregnation layer 4.

The adhesive layer 5 preferably has a thickness of less than 150 µm. The thickness of the adhesive layer is for example approximately equal to 140 µm.

Consequently, the total thickness of the device 1 (i.e. of the stack of layers previously described) is less than 3 mm, preferably even less than 2 mm. The device 1 is thus flexible and can therefore conform to the shape of the area of the body on which it will be placed.

Method of use

According to another aspect, a method of using the device 1 will be described with reference to the . First, the user obtains the device 1. He also obtains an electrically conductive activation product.

In a step a), the user applies activation product to the device 1 so as to cover at least the permeable zone(s) 62 of the stencil layer 6 and therefore the corresponding free zone(s) 44 of the impregnation layer 4.

The activation product then impregnates the free zones 44 and, consequently, the activation zones 42 of the impregnation layer 4.

In a step b), the user removes the stencil layer 6 so that said stencil layer 6 no longer covers the impregnation layer 4.

In a step c), the device 1 is applied to the user's skin so that free areas 44, in particular the second and third free areas 44b and 44c, of the impregnation layer 4, are in contact with the user's skin.

The impregnation of the first activation zones 42a (located opposite the free spaces 243 of the galvanic couples 240) causes an oxidation-reduction reaction within the galvanic couples 240. This allows the activation of the galvanic couples 240 and therefore of the current generator 24.

An electric current is generated and passes through the user's skin as for example illustrated in .

Preferably, the materials in contact with the user's skin comprise only non-woven fabric (areas of the impregnation layer 4), activation product and possibly an adhesive material of the adhesive external surface 53 of the adhesive layer 5. Consequently, the user's skin is only in contact with skin-friendly materials (i.e. it is unlikely that any allergic reaction of the skin will occur). This therefore improves the comfort of use of the device 1 and considerably limits, or even eliminates, any risk of redness appearing on the area treated with the device 1.

Manufacturing process

According to a second aspect, with reference to the , a method of manufacturing the device 1 is proposed. Preferably, a set of devices 1 is manufactured on the same support and each device 1 is then detailed by cutting the set.

In a step a), preferably initial, at least one support layer 2 is formed. For this, at least one printed assembly comprising a main electrode 22, a counter-electrode 23 and a current generator 24 on at least one support film 21 is printed from conductive inks, preferably by screen printing.

A plurality of sets can be printed on the same support to optimize manufacturing.

Step a) preferably comprises a step a1), preferably initial, of printing connectors, advantageously in carbon, as illustrated in . The printed carbon connectors preferably comprise couple connectors 246 for electrically connecting the galvanic couples 240 of a current generator 240. The printed carbon connectors also preferably comprise the first connector 244 or the last connector 245 for connecting at least one of the main electrode 22 and the counter electrode 23 to one of a first conductive pole and a second conductive pole of a galvanic couple 240 of the current generator 24. As can be seen in the , the couple connectors 246 and the last connector 245 have, in top view, a p-shape (or symmetrically q-shape), that is to say that they have a first full zone, substantially square and a tail (or thin zone).

Step a1) may optionally also include the printing of a multitude of carbon dots intended to be arranged in the main electrode 22.

Preferably, the carbon ink is then heated with an anneal at 110°C for 3 minutes. The annealing serves to stabilize the ink and give the carbon the necessary electrical properties.

Step a) then preferably comprises a step a2), preferably intermediate, of printing, preferably in zinc, for each galvanic couple 240 of one of the first conductive pole 241 and the second conductive pole 242, as illustrated in .

Preferably, the zinc is deposited partially above the carbon connectors. Advantageously, as can be seen in the , the zinc ink covers the full shape of the p or q formed by each of the couple connectors 246 and the last connector 245 without however covering the tail of the latter.

Preferably, the zinc is then heated with an annealing at 110°C for 3 minutes. The annealing stabilizes the ink and gives the zinc the necessary electrical properties.

Then, step a) preferably comprises a step a3), successive to step a2), of printing in silver and/or silver chloride for each galvanic couple 240 of the other among the first conductive pole 241 and the second conductive pole 242 (i.e. the conductive poles which are not those printed in zinc). Step a3) also preferably comprises the printing in silver and/or silver chloride of the main electrode 22 and the counter-electrode 23.

Step a3) results in the final support layer 2 illustrated in .

The manufacturing method further comprises a step b) of forming at least one impregnation layer 4 by arranging at least one impregnation film 41 on the at least one support layer 2.

Advantageously, step b) is implemented by heat-sealing. As explained above, step b) may preferably comprise the installation of a plurality of impregnation films 41, for example three impregnation films 41a, 41b, 41c, in order to form the impregnation layer 4.

Then, in a step c), at least one stencil layer 6 is formed by arranging at least one stencil film 61 on the at least one impregnation layer 4. Step c) aims in particular to arrange permeable zones 62 of a stencil layer 6 opposite the free zones 44 of the impregnation layer 4. It will be understood that the stencil film 61 can itself come from a manufacturing sub-process which can include in particular steps of forming permeable zones 62, for example by cutting, drilling, stamping, etc.

Preferably, the at least one stencil film 61 is arranged on the impregnation layer 4 so that, for the at least one printed assembly, at least one permeable zone 62 of the at least one stencil film 61 is arranged opposite at least part of a galvanic couple 240 of the current generator 24 extending at least in part of the free space 243 of the galvanic couple 240.

Advantageously, step c) consists of simultaneously forming the stencil layer 6 and the adhesive layer 5 by placing an assembled assembly comprising the stencil layer 6 and the adhesive layer 5 on the impregnation layer 4. In this case, as explained previously, a double-sided adhesive film 51 may be used, one of the faces comprising a cover forming the stencil film 61.

The assembly of the stencil layer 6 to the impregnation layer 4 can for example be implemented by heat welding.

The manufacturing method advantageously comprises a step d) of obtaining a device 1 by cutting into the desired shapes (for example drop, circle and triangular) defined previously from the superposition of the support layers 2, impregnation 4 and stencil 6.

Kit

According to another aspect, there is provided a kit for treating the skin of a user by iontophoresis and/or electrostimulation comprising:
- a device 1;
- an electrically conductive activation product intended to soak the impregnation layer 4 and to activate the current generator 24.

Another kit for implementing device 1 will be described. The kit includes:
- an assembly comprising a support layer 2 and an impregnation layer 4 and preferably a stencil layer 6 assembled;
- possibly a separate stencil layer 6;
- and an electrically conductive activation product.

The stencil layer 6 is possibly detached, distinct from the device 1. It can then be envisaged that the stencil layer 6 is reusable and can therefore be used on different devices 1.

Preferably, the activation product has a pH of between 4 and 10, in particular between 5 and 7 so as to respect the user's skin and not attack it. Preferably, the pH of the activation product is adapted to the materials of the galvanic couples 240 so as to optimize the effectiveness of the device 1.

For example, in the case of a galvanic couple 240 whose second conductive pole 241 (forming the anode) is made of zinc, the more acidic the activation product, the more the zinc will oxidize and the better the redox reaction and therefore the efficiency of the device 1 will be. Thus, it will be preferred in this case to use an activation product whose pH is of the order of 5. In other cases, it may be preferred for the pH to be higher, i.e. for the activation product to have a pH of the order of 7.

The activation product may contain an active agent to be diffused into the skin for skin treatment such as vitamin C.

To use the kit, the user arranges the stencil layer 6 so that the permeable areas 62 are opposite the free areas 44, if the latter is not already. Marks could be drawn on the impregnation layer 4 to indicate the free areas 4. Furthermore, the stencil layer 6 could have the same shape as the impregnation layer 4 so that the user can correctly position the stencil layer 6 by superimposing the perimeter of the stencil layer 6 on the perimeter of the impregnation layer 4.

Then, the user can implement the method of use described above.

The invention is not limited to the embodiments described and shown in the attached figures. Modifications remain possible, in particular from the point of view of the constitution of the various technical characteristics or by substitution of technical equivalents, without departing from the general teaching.

Claims (15)

Device (1) for treating the skin of a user by iontophoresis and/or electrostimulation intended to be applied to the skin of the user, the device (1) comprising a support layer (2) comprising at least one support film (21) and comprising a main electrode (22), a counter-electrode (23) and a current generator (24) electrically connected to the main electrode (22) on the one hand and to the counter-electrode (23) on the other hand, in which the current generator (24) comprises a plurality of galvanic couples (240) connected in series, each galvanic couple (240) being formed of a first conductive pole (241) forming a cathode and a second conductive pole (242) forming an anode, and in which the galvanic couples (240) are adjacent two by two and electrically connected two by two, the first conductive pole (241) of one of the galvanic couples (240) being electrically connected to the second conductive pole (242) of an adjacent galvanic couple (240). The device of claim 1, wherein the plurality of galvanic couples (240) connected in series comprises a first galvanic couple (240a) and a last galvanic couple (240d), the first conductive pole (241) of the first galvanic couple (240a) being electrically connected to the main electrode (22) and the second conductive pole (242) of the last galvanic couple (240d) being electrically connected to the counter electrode (23), or the second conductive pole (242) of the first galvanic couple (240a) being electrically connected to the main electrode (22) and the first conductive pole (241) of the last galvanic couple (240d) being electrically connected to the counter electrode (23). Device according to any one of claims 1 and 2, in which the main electrode (22) and the counter-electrode (23) are made of silver and/or silver chloride, each first conductive pole (241) forming a cathode comprising silver and/or silver chloride and each second conductive pole (242) forming an anode comprising zinc. Device according to any one of claims 1 to 3, in which two adjacent galvanic couples (240) are electrically connected via carbon connectors (246). The device of claim 4, wherein a carbon connector extends below a second conductive pole (242). Device according to any one of claims 1 to 5, wherein the main electrode (22) is electrically connected to a first conductive pole (241) via a carbon connector and the counter electrode (23) is electrically connected to a second conductive pole (242) via a silver and/or silver chloride connector. Device according to any one of claims 1 to 6, in which the support layer (2) comprises at least three galvanic couples (240), preferably at least four galvanic couples (240). Device according to any one of claims 1 to 7, in which, for each galvanic couple (240), the first conductive pole (241) and the second conductive pole (242) are separated from each other by a free space (243). Device according to claim 8, in which the first conductive pole (241) of a galvanic couple (240) and the second conductive pole (242) of a galvanic couple (240) are separated by a distance of between 0.5 mm and 5 mm, preferably between 1 mm and 3 mm, for example equal to 2 mm. Device according to any one of claims 8 and 9, comprising an impregnation layer (4) comprising at least one impregnation film (41), the impregnation layer (4) covering at least the main electrode (22), the counter-electrode (23) and the current generator (24), device (1) in which the parts of the impregnation layer (4) arranged above the free spaces (243) are intended to be covered with an electrically conductive activation product. Device according to claim 10, in which the device comprises a stencil layer (6) covering the impregnation layer (4) and comprising at least one stencil film (61), the stencil layer (6) comprising at least one permeable zone (62) adapted to allow an electrically conductive activation product to pass only at the level of at least one predefined zone of the impregnation layer (4), called the free zone (44), the free zone (44) being intended to be covered with the activation product. Device according to any one of claims 1 to 11, wherein the current generator (24) comprises at least two current generation assemblies (247) comprising a plurality of galvanic couples (240) connected in series, the two current generation assemblies (247) being connected in parallel. Method of manufacturing a device according to one of claims 1 to 12, comprising a step of:
a) forming the support layer (2) by printing from inks, preferably by screen printing, at least one printed assembly comprising a main electrode (22), a counter-electrode (23) and a current generator (24) on the at least one support film (21). The method of claim 13, wherein step a) comprises a step of:
a1) printing carbon connectors (246) intended to electrically connect galvanic couples (240) of a current generator (24) and at least one of the main electrode (22) and the counter-electrode (23) to one of a first conductive pole (241) and a second conductive pole (242) of a current generator (24). A method according to any one of claims 13 and 14, wherein step a) comprises steps of:
a2) zinc printing for each galvanic couple (240) of one of the first conductive pole (241) and the second conductive pole (242);
a3) printing in silver and/or silver chloride for each galvanic couple (240) of the other among the first conductive pole (241) and the second conductive pole (242) and printing in silver and/or silver chloride of the main electrode (22) and of the counter-electrode (23).