HIGHLY BREATHABLE ELECTRONIC PATCH AND METHOD FOR PRODUCING SUCH PATCH

Abstract

The invention is related to an electronic patch (EP) comprising at least: (A) a first polymeric layer (A) with a first surface a) and a second surface b) which is parallel to surface a), whereby layer (A) provides a water vapour permeability of 500 g/m.sup.2d; (B) an electronic device (B) providing at least one flat surface which is positioned on the first surface a) of the first polymeric layer (A); (C) optionally a second polymeric layer (C) providing a vapour permeability of 500 g/m.sup.2d, preferably in a range of 500 to 2000 g/m.sup.2d; (D) optionally a further layer (D) as water barrier positioned between the electronic device (B) and the first polymeric layer (A); (E) optionally an adhesive on the second surface b) of the first polymeric layer (A); (F) optionally a polymeric foam (F) with a moisture vapour transmission rate (MVTR) of 500 g/m.sup.2d, more preferably in a range of 550 to 2000 g/m.sup.2d, most preferably in a range of 600 to 1500 g/m.sup.2d covering the electronic device (B), determined according to DIN 53122-1:2001-08;
whereby the electronic patch (EP) is surrounded by the first polymeric layer (A) and optionally the second polymeric layer (C) in a way that the overall water vapour permeability of the electronic patch (EP) is 400 g/m.sup.2d as well as a process for the production of the electronic patch (EP).

Claims

1. An electronic patch (EP) providing at least one flat surface ep) which is arranged to be placed on the skin of a user, the electronic patch (EP) comprising at least: (A) a first polymeric layer (A) with a first surface a) and a second surface b) which is parallel to surface a), whereby layer (A) provides a moisture vapor transmission rate (MVTR) of 500 g/m.sup.2d; (B) an electronic device (B) providing at least one flat surface b) which is positioned on the first surface a) of the first polymeric layer (A), wherein the electronic device (B) is optionally surrounded by a water barrier (WB); (C) optionally a second polymeric layer (C) providing a moisture vapor transmission rate (MVTR) of 500 g/m.sup.2d; (D) optionally at least one further layer (D) as water barrier (WB) positioned between the electronic device (B) and the first polymeric layer (A) or between the electronic device (B) and the second polymeric layer (C) or both; (E) optionally an adhesive (E) on the second surface b) of the first polymeric layer (A); (F) optionally a polymeric foam (F) with a moisture vapor transmission rate (MVTR) of 500 g/m.sup.2d covering the electronic device (B); wherein a surface area ep1) which covers 50% of the total surface of the flat surface ep) of the electronic patch (EP) is superimposed by material providing an overall moisture vapor transmission rate (MVTR) of 400 g/m.sup.2d.

2. The electronic patch (EP) according to claim 1, wherein 50%, of the total volume of the electronic patch (EP) is filled with a material that provides a moisture vapor transmission rate (MVTR) greater than 500 g/m.sup.2d.

3. The electronic patch (EP) according to claim 1, wherein the polymer of the first polymeric layer (A) and optionally the second polymeric layer (C) are each independently selected from the group consisting of a thermoplastic elastomer, a silicone, an (expanded) polytetrafluorethylene (PTFE), a polyamide, a polyphthalamide, a polyblockamide, a polyacrylate, a polycarbonate, a co-polycarbonate, a polyether-blockamide, a polyester, a co-polyester, a polyimide, a polyvinylchloride, a polyolefine and a combination of at least two of these.

4. The electronic patch (EP) according to claim 1, wherein the first polymeric layer (A) and optionally the second polymeric layer (C) provides at least one of the following properties: (A1) a thickness in a range of 10 to 500 m; (A2) a surface area in a range of 1 to 1000 cm.sup.2; (A3) an aspect ratio of thickness to length or width building the surface area is in a range of 1:10 to 1:10000; (A4) vapor permeability of 500 g/m.sup.2d; (A5) a vapor permeability in a range of 500 to 3000 g/m.sup.2d.

5. The electronic patch (EP) according to claim 1, wherein the electronic device (B) provides at least one of the following properties: (B1) a thickness in a range of 0.5 m to 5 cm; (B2) a volume in a range of 0.5 to 500 mm.sup.3; (B3) optionally, the electronic device is surrounded by a water barrier (WB); (B4) at least one electronic component selected from the group consisting of antenna, battery, wires, rigid PCB boards, flexible PCB boards, chips, memory elements, sensors and combinations of at least two of these.

6. The electronic patch (EP) according to claim 1, wherein at least one of the at least one further layer (D) is present and is positioned between the electronic device (B) and the first polymeric layer (A), and optionally between the electronic device (B) and the second polymeric layer (C).

7. The electronic patch (EP) according to claim 1, wherein the ratio of the surface area of the first polymeric layer (A) to the surface area of the first layer (D) is in a range of from 100:1 to 1.5:1.

8. The electronic patch (EP) according to claim 1, wherein the further layer (D) is present and provides at least one of the following properties: (D1) a thickness in a range of 1 to 500 m; (D2) a surface area in a range of 0.1 to 900 cm.sup.2; (D3) a vapor permeability smaller than 400 g/m.sup.2d.

9. The electronic patch (EP) according to claim 1, wherein at least one of the at least one further layer (D) is present and is made of one selected from the group consisting of aluminum, a polymer foil, a foam, a foil/foam combination, a coated polymeric foil, a glass, a ceramic and a combination of at least two of these.

10. The electronic patch (EP) according to claim 1, wherein at least one of the at least one further layer (D) is present and is made of a polymer selected from the group consisting of polyethylene, polypropylene, polyethylene terephthalate, polystyrene, polyvinylchloride, polyamide, and a mixture of at least two of these.

11. The electronic patch (EP) according to claim 1, wherein the polymeric foam (F) is present and is selected from the group consisting of polyurethanes, thermoplastic polyurethanes, polyolefinic materials, silicones and a mixture or a combination of at least two of these.

12. A process for producing an electronic patch (EP) providing a flat surface ep) on its outside, the process comprising at least the following steps: (I) providing a flat first part of a first polymeric layer (A) comprising a first surface area ep1) and a second surface area ep2), wherein the first polymeric layer (A) provides a vapor permeability in a range of 500 to 3000 g/m.sup.2d; (II) optionally, providing a further layer (B) on the second surface area ep2) of the first part of the first polymeric layer (A) to cover 70% of the first part of the first polymeric layer (A); (III) optionally applying of at least one electrical pathway onto first polymeric layer (A) and/or the further layer (D; (IV) providing an electronic device (B) on the first part of the first polymeric layer (A) so that the electronic device (B) is not in direct contact with the polymeric layer (A); (V) optionally, providing a second further layer (D) on the electronic device (B); (VI) optionally providing a polymeric foam (F) with a vapor permeability in a range of 500 to 1000 g/m.sup.2d covering the electronic device (B); (VII) covering the electronic device (B) by a second part of the first polymeric layer (A) or a second polymeric layer (C) so that overlapping edges of the first part of the first polymeric layer (A) and the second part of the first polymeric layer (A) or of the first part of the first polymeric layer (A) and the second polymeric layer (C) are formed; (VIII) fixing the overlapping edges of the first part of the first polymeric layer (A) and the second part of the first polymeric layer (A) or fixing the second polymeric layer (C) with the first part of the first polymeric layer (A) achieving an electronic patch (EP) which is totally surrounded by the first polymeric layer (A) or partially surrounded by the first polymeric layer (A) and partially surrounded by the second polymeric layer (C); (IX) optionally providing an adhesive onto the underside of the electronic patch (EP); wherein the first surface area ep1) which covers 50% of the total surface of the flat surface ep) of the electronic patch (EP) is superimposed by material providing an overall moisture vapor transmission rate (MVTR) of 400 g/m.sup.2d.

13. The process according to claim 12, wherein the fixing in step (VIII) is achieved by welding the polymeric layers (A) and optionally (C) at their overlapping edges, preferably at a temperature in a range of 40 C. to 350 C.

14. An electronic patch (EP) obtained by the process according to claim 12.

15. (canceled)

Description

FIGURES

[0085] The FIGS. 1 to 3 show:

[0086] FIG. 1: a schematic view of a non-breathable arrangement of electronics, electrical pathways of a sensor of the prior art;

[0087] FIG. 2: a schematic view of an arrangement of electronics, electrical pathways of a sensor according to the invention;

[0088] FIG. 3: a scheme of process steps according to the process according to the invention.

[0089] In FIG. 1 a scheme of a conventional electronic patch 2 is shown where a substrate (not shown) is covered by a water barrier 4 over the whole surface area of the substrate or the electronic patch. The electrical connections 6 and pathways 8 are positioned on the barrier 4 to connect the electronic device 10 with a further device (not shown).

[0090] In FIG. 2 a scheme of an electronic patch (EP) 20 according to the invention is shown. Here, a first polymeric layer (A) 12 in form of a water vapor-permeable TPU film, for example VPT 9101 T natural of Epurex Films GmbH & Co.KG is provided. The surface a) 12c of the first polymeric layer (A) 12 is divided in a first surface area ep1) 12a which is superimposed by material with an MVTR of 500 g/m.sup.2d and a second surface area ep2) 12b which is covered by material of the further layer (B) 4. The small areas of the second surface area ep2) 12b are covered by a water barrier material in form of further layer (D) 4. These areas 12b are screen printed by the water barrier material onto the first polymeric layer (A) 12. Onto these areas 12b of the first polymeric layer (A) 12 an electronic device 10 is deposited or printed and electrical pathways 8 are printed. The electrical pathways 8 connect the electronic device 10 with electrical connections 6. These electrical connections 6 can be used to connect the electronic device 10 with electronic devices, like batteries or computers in the surrounding of the electronic patch (EP). If needed, the electrical connection 6 might be physically connected through the overlaying layers (C), (A) and/or (D). In the example shown in FIG. 2, 85% of the surface a) 12c is covered by material with a moisture vapour transmission rate (MVTR) of 500 g/m.sup.2d and builds first surface area ep1) 12a. Accordingly, the second surface area ep2) 12b builds 15% of the total surface a) 12c.

[0091] In FIG. 3, in the first scheme 20, a flat first part of a first polymeric layer (A) 12 comprising a first surface area ep1) 12a and a second surface area ep2) 12b, is shown. The upper view of the scheme 20 is a top view onto the first polymeric layer (A) 12 and the lower view of scheme 20 is a side view of the first polymeric layer (A) 12. The perspective of the views also applies to schemes 30, 40, 50, 60 and 70. According to the process according to the invention in step (I) 100 a water vapor-permeable TPU film in form of a VPT 9101 T natural of Epurex Films GmbH & Co KG a subsidiary of Covestro Deutschland AG, Germany in 25 m thickness is provided.

[0092] In optional step (II) 200 a further layer (D) 4 may be provided in a conventional screen printing process onto the second surface area ep2) 12 of the first polymer layer (A) 12 providing surface a) 12c. As can be seen in the top view and also in the side view of scheme 30 the further layer (D) 4 is positioned in the middle of the first polymeric layer (A) 12. By applying this further layer (D) 4 a water vapor barrier is applied onto the first layer (A) 12. For this purpose the printing paste LOCTITE EDAG PF 455B E&C from Henkel was applied by a normal screen printing process.

[0093] In step (IV) 400 an electronic device 10 is placed onto the further layer (D) 4 separating the first polymeric layer 12 from the electronic device 10. This is established by a manual placement (pick&place process).

[0094] In optional step (V) 500, a further water barrier layer (D) 4 may be applied onto the electronic device 10. This is established by applying printing paste LOCTITE EDAG PF 455B E&C from Henkel by the screen printing process as described for step (II) or by a brushing process.

[0095] In optional step (VI) 600 a water vapor-permeable thermoplastic polyurethane foam (F) 14 from Mayser (Bluefoam MGT-160 in 1.5 mm thickness) may be applied onto a part of the first layer 12 as well as the surface of the electronic device 10. The foam (F) 14 may be provided directly on the electronic device 10 or onto the water barrier layer (D) 4 covering the electronic device 10 if applied in optional step (V).

[0096] In step (VII) 700 a further water vapor-permeable thermoplastic polyurethane film 12 is finally applied onto the structure built after step (VI) 600, especially onto the foam 14 which covers the electronic device 10 surrounded by the water barrier layer (D) 4. As material of the further film 12, a VPT 9101 T natural of Epurex Films GmbH & Co KG a subsidiary of Covestro Deutschland AG, Germany is applied in a thickness of 25 m. This layer arrangement forms the electronic patch (EP) 120.

[0097] In a lamination process, in step (VIII) 800 the edges of the entire patch (EP) 120 are welded together at a temperature of 150 C. for 3 seconds.

[0098] Optionally, a breathable adhesive, for example Baymedix A of Covestro AG, Germany is applied to the bottom of electronic patch (EP) 120, preferably directly onto the outer surface (ep) of the first polymeric layer 12.

[0099] In the example shown in FIG. 3, 80% of the surface a) 12c is covered by material with a moisture vapour transmission rate (MVTR) of 500 g/m.sup.2d and builds first surface area ep1) 12a. Accordingly, the second surface area ep2) 12b builds 20% of the total surface a) 12c.

Methods

[0100] Moisture Vapour Transmission Rate (MVTR): all values for the moisture vapour transmission rate have been determined according to DIN 53122-1:2001-08.