This disclosure relates to a passive system for retaining moisture in a textile electrode worn against the skin.
It is known to use textile electrodes for measuring physiological parameters of the human body. The use of textile electrodes, however, is constrained by their high impedance when their conducting material is dry. In addition, electrodes constructed from conductive threads woven or knitted together and placed against bare skin obtain relatively poor physiological signal quality (e.g., an electrocardiographic signal which is representative of the heart activity of a user) as compared to traditional electrodes which often use a highly conductive fluid or gel to place the electrode or conductive element in electrical contact with the user's skin. The gel or fluid reduces the impedance in contact with the electrode so that very small changes of electrical signals such as those measured by electroencephalography (EEG), electrocardiography (ECG) and electromyography (EMG) can be measured.
Prior art textile electrodes known by the inventors have attempted to improve their signal quality by ensuring the presence of moisture between the electrodes and the skin to allow ionic conduction between the two interfaces and thus, obtain a sufficient conductivity to detect signals generated by the human body. Typical system either provide a source of fluid to the electrode that maintains a moisture level between the electrode and the user's skin or rely on sweat generated by the user using physical activity to maintain a moisture level. The latter approach is highly dependent on the user's sweat output and level of physical activity, and severely limits the usefulness of the textile electrode. The former has to contend with the high level of fluid evaporation and absorption that can make the performance of the electrode unpredictable as the moisture level fluctuates depending on the user activity and environment.
In response, the prior art has taken one of two common approaches to maintain the moisture level in a textile electrode. The first adds a separate fluid reservoir and a system for moving fluid from the reservoir to the electrode. The second places a wetted material behind the electrode and separates the two by a semi-permeable membrane that allows moisture to flow from the wetted material to the electrode.
Both approaches, however, have serious drawbacks. Reservoir systems, for example, add a bulky fluid container that must be placed somewhere on the user, and can require an active transport mechanism in order to move fluid to the electrode. Systems with semi-permeable barriers are difficult to rewet, dry, and clean, which makes their wetted material prone to bacteria growth and breakdown.
The present disclosure relates to a system for continuously humidifying a textile electrode during its use by a human being. Certain embodiments of the present disclosure provide for a system for maintaining a moisture content of a textile electrode, where the textile electrode is part of a garment and the textile electrode is positioned against the skin of a wearing of the garment. Some embodiments include a reservoir made from a material with hydrophilic and hydrophobic properties. In some instances, the reservoir is made from a skincore material such as natural wool, which has a hydrophilic or hygroscopic cortex and a hydrophobic exterior, positioned directly against the side of a textile electrode opposite the user's skin. Some embodiments also include an impermeable outer sealing layer surrounding the skincore material and the textile electrode, such that the outer sealing layer extends beyond the outer edges of the textile electrode. The impermeable material is heat activated at the outer edge such that the material flows into the textile beyond the edges of the textile electrode and forms a moisture barrier surrounding the edges of the textile electrode. Some embodiments also include an electrical contact point on the textile electrode that is connecting one or more conductive wires from outside the sealing layer to the textile electrode. In some instances, an inner sealing layer is disposed around the electrical contact to separate the conductive wires and the portion of the textile electrode in contact with the conductive wires from moisture of the skincore material and the user's skin. The skincore material inside the sealing layer is configured to receive and retain moisture from the user's skin through the textile electrode, as well as from a pre-wetting application of a fluid, such as water or saltwater, to the exposed user-facing side of the textile electrode.
In operation, some embodiments of the present system control the humidity or moisture level present in a textile electrode by providing a reservoir material directly against the electrode that, due to the material properties of the reservoir material, is able to maintain a high level of moisture in the textile electrode while the textile electrode and outer sealing layer is positioned against the user's skin. The initial wetting of the reservoir material can, in some instances, provide enough moisture to allow the textile electrode to function at a desired level for many hours, depending on the size and amount of fluid initially added to the reservoir material. The hydrophobic properties of the exterior of the reservoir material prevent excess evaporation due to exposed fluid, and the hydrophilic properties of the interior of the reservoir material allow substantial fluid retention and controlled evaporation of that fluid to the textile electrode over a long period of time. Additionally, the hydrophilic properties of the reservoir material enable the reservoir to readily absorb moisture from sweat excreted from the user's skin adjacent to the textile electrode. The outer sealing layer's contact with the user's skin surrounding the textile electrode helps to retain this excreted moisture inside the outer sealing layer where it can humidify the textile electrode and excess moisture can be stored by the reservoir material for later evaporation when the textile electrode's moisture level drops below that of the reservoir material.
In operation, by controlling the humidity level of the textile electrode, some embodiments of the present disclosure provide a system for maintaining optimum electrical signals reception by the textile electrode while allowing to be worn for long periods; thereby achieving quality measurements. Some embodiments of the present disclosure also provide for a system designed to operate in the normal life cycle of a garment, including reuse and multiple washes. Because the textile electrode and reservoir material are exposed to the interior side (i.e., user-facing side) of the garment, washing and cleaning of the reservoir material is not inhibited by the outer sealing layer, which is the same mechanism by which the reservoir material can be pre-wetted before use by simply applying a fluid to the inner side of the textile electrode.
Some embodiments of the present disclosure provide for a system designed to be simple to incorporate into a garment and operate in the normal life cycle of a measure of the person wearing the garment. During this cycle, the body contact provides for retention of moisture in the reservoir material, as well as a resupply of moisture from the user's sweat. Additionally, heat from the user's skin helps to heat the reservoir material, which helps release moisture from the reservoir material. Thus, some embodiments of the present disclosure provide for a passive system for maintaining the moisture content of a textile electrode during use of the garment. Additionally, some embodiments of the present disclosure provide for a system that can be integrated into a garment with little to no noticeable change in the garment's feel or function beyond the present of moisture in the regions of the garment with textile electrodes. Some embodiments of the present disclosure provide for flexible materials that can be integrated into a garment to so as to not inhibit contact between the inner side of the textile electrode and the user's skin, which improves the quality and reliability of the electrical signal received by the textile electrode.
Certain embodiments of the present disclosure include a system for maintaining moisture in a textile electrode. The system can include a textile layer having a textile electrode region knitted therein and an insulated region adjacent to the textile electrode region, a reservoir material positioned above the outer side of the textile electrode region, and an outer sealing layer positioned above the reservoir material, the outer sealing layer extending over and around the reservoir material and the textile electrode region. The textile electrode region and insulated region together can define a continuous textile section. The textile layer can have an inner side and an outer side opposite the inner side, the inner side of the textile electrode region being exposed and configured to contact against a user's skin. The textile electrode region can be knitted from an electrically conductive yarn having an exposed electrically conductive surface and the insulated region can be knitted from an electrically insulated or electrically inert yarn. The outer sealing layer can extend through a thickness of the textile layer to the inner side of the textile layer. In some embodiments, the outer sealing layer defines a moistures barrier around the textile electrode region and the reservoir material and through the thickness of the textile layer around the textile electrode.
The system can include an electrical contact between a conductive wire received through the outer sealing layer and the textile electrode. In some embodiments, the system includes an inner sealing layer surrounding the electrical contact.
The exposed electrically conductive surface of the electrically conductive yarn can include a silver coating. The outer sealing layer can include an exterior film layer above the reservoir material and the textile electrode region and an adhesive material securing the exterior film to the textile layer, with the adhesive material extending through the thickness of the textile layer to the inner side of the textile layer.
In some embodiments, the insulated region includes a conductive trace region knitted therein, the conductive trace region extending from a border of the textile electrode and through the outer sealing layer. The conductive trace region can be knitted from a hybrid yarn containing a non-conductive yarn twisted with a conductive wire, the conductive wire having an exterior coating with an insulating material, and the textile electrode region can be electrically connected to a conductive wire from the conductive trace region that the exterior coating removed. In some embodiments, the insulated region includes an electrical inert region, with the conductive trace region extending through the electrically inert region and the electrical inert region is knitted from an electrically inert yarn. The textile layer having the textile electrode can be a first layer, with the system further includes a second layer of the hybrid yarn knitted out of the conductive trace region and over a portion of the electrode region to form a two-layer section in the textile electrode region, where the exterior coating of the conductive wire of a portion of the conductive trace region in the two layer section is removed to expose a portion of the conductive wire and the exposed portion of the conductive wire is electrically connected with the electrode region via a conductive material. In some embodiments, the non-conductive yarn is removed where the exposed portion of the conductive wire is electrically connected with the electrode region and an inner sealing layer can surround the exposed portion of the conductive wire.
The reservoir material can include a skincore fiber having a hydrophilic or hygroscopic cortex and a hydrophobic exterior. The reservoir material can be natural wool and can be felted. The textile layer can include a single knitted layer, which can be knitting using intarsia knitting. In some embodiments, the textile layer defines a garment. In some embodiments, the electrode region is configured to pick up electrical signals from the user's body. In some embodiments, the insulated region surrounds the textile electrode region.
Other implementations, features, and advantages of the subject matter included herein will be apparent from the description and drawings, and from the claims.
This disclosure will be more fully understood from the following detailed description taken in conjunction with the accompanying drawings, in which:
Certain exemplary embodiments will now be described to provide an overall understanding of the principles of the structure, function, manufacture, and use of the devices and methods disclosed herein. One or more examples of these embodiments are illustrated in the accompanying drawings. Those skilled in the art will understand that the devices and methods specifically described herein and illustrated in the accompanying drawings are non-limiting exemplary embodiments and that the scope of the present disclosure is defined solely by the claims. The features illustrated or described in connection with one exemplary embodiment may be combined with the features of other embodiments. Such modifications and variations are intended to be included within the scope of the present disclosure.
Example Textiles with Integrated Conductive Traces
The textile electrodes 130 can be arranged to, for example, pick up or sense electrical signals from the user's body, such as those related to heart rate and heart function (e.g., the signals for use in forming an electrocardiogram EKG). In some embodiments, the garment 100 includes four textile electrodes 130, positioned with respect to the user's body in order to provide a high-quality EKG signal. The conductive traces 120 connect the textile electrodes 130 to the electrical device 199 via the conductive wires integrated into the hybrid yarn from which the conductive traces 120 are knitted. The conductive wire of the hybrid yarn can be coated with an insulating polymer, which is able to be removed at the points of contact with the textile electrodes 130 and the electrical device 199.
In some embodiments, the hybrid yarn is constructed from a highly inelastic material, such as meta-aramid or para-aramid (e.g., Kevlar® or Twaron®) or a material with similar material properties to protect the integrated conductive wires from damage or being severed during the knitting process and being damaged or severed during normal wear of the garment 100, such as Ultra High Molecular Weight Polyethene (UHMWPE), Polybenzimidazole (PBI), Polyphenylene Benzobisoxazole (PBO), High Strength Polyester, Liquid-Crystal Polymer (LCP), or spider silk. In some embodiments the hybrid yarn is made with a fire retardant and self-extinguishing material, such as para-aramid or material with similar properties according to the ASTM D6413/D6413M Standard Vertical Test Method for Flame Resistance of Textiles to enable the insulating layer and nonconductive yarn to be removed using ablation. The conductive wire can be, for example copper wire or copper-clad stainless-steel sire. Additionally, the textile electrodes 130 may be knitted or otherwise constructed with a conductive wire, such as silver or copper wire or a nonconductive yarn (e.g., nylon, polyester, cotton, or wool) coated with a conductive material such as silver or copper. In some embodiments, the standard material 110, textile electrodes 130, and conductive traces 120 are knitted together into a single-layer garment 100 without seams.
Example of a Hybrid Conductive Yarn
In one example, the hybrid yarn 200 includes two stands of copper-clad stainless steel or copper with between 5 to 12 twists per inch around a Kevlar strand. The 5 to 12 twists per inch construction is for a strand of Kevlar and a 50 micron conductive wire (e.g., 43 micron thick metal and a 3-4 micron thick coating of polyurethane) that when twisted together suitable to knit a textile at 15 gauge. The hybrid yarn in
Nonconductive yarns 210 made with para aramid or similar materials have many advantages, such as being strong, but relatively light. The specific tensile strength (stretching or pulling strength) of both Kevlar 29 and Kevlar 49 is over eight times greater than that of steel wire. Unlike most plastics it does not melt: it is reasonably good at withstanding temperatures and decomposes only at about 450° C. (850° F.).
Accordingly, the hybrid yarn 200 can be laser ablated or burned to remove the nonconductive yarn 210 and the coating on the conductive wire 220.
Examples of Connecting a Hybrid Conductive Yarn to a Textile Electrode
Example Moisture Retaining Systems
Specifically, data is more effectively captured when the textile electrode is stable and damp. As such, illustrative embodiments add an outer film layer around the textile electrode region 130.
For example, the added layer may include a thermoplastic adhesive cover film (or thermoplastic textile laminate) that mitigates evaporation of moisture from the region of the textile electrode region 130 through the garment 100. Moreover, adding an additional layer of fabric, between the textile electrode region 130 and the film improves sweat absorption. Multiple tests were conducted with a variety of different materials used as the hydrophilic layer, such as non-woven wool batting, dense polyester knit (brand name Axe suede) and superhydrophobic fiber and superhydrophobic yarn (as produced by Technical Absorbents, Grimsby, UK). Framis ‘Portofino’ laminate (polyester jersey +TPU adhesive) and Framis ‘Heavy Dream’ (TPU Cover-Film) was used as a stabilization ‘patch’. Here it was discovered that hydrophobic/hydrophilic materials, such as natural wool, are superior when used as the reservoir material. Natural wool absorbs salt water well and does not readily evaporate. Natural wool is also naturally fire resistant and has anti-microbial properties that are consistent with its intended use in this embodiment next to the skin. Further, natural wool washes and dries without deterioration. Other hydrophobic materials, such as those tested, can also be used to form the reservoir but wool has the best characteristics for performance in the garment 100. The wool can be any form including loose fiber, or layers of knitted or woven wool, or felted wool, or non-woven wool batting. While some embodiments are 100% wool, wool blended with other fibers at no less than 70% wool/30% other fibers can also be used.
Examples of Assembling a Moisture Retaining System
The embodiments of the invention described above are intended to be merely exemplary; numerous variations and modifications will be apparent to those skilled in the art. One skilled in the art will appreciate further features and advantages of the disclosure based on the above-described embodiments. Such variations and modifications are intended to be within the scope of the present invention as defined by any of the appended claims. Accordingly, the disclosure is not to be limited by what has been particularly shown and described, except as indicated by the appended claims. All publications and references cited herein are expressly incorporated herein by reference in their entirety.
This application claims priority from U.S. Provisional Application Ser. No. 62/832,098 filed Apr. 10, 2019 and entitled GARMENTS WITH INTEGRATED ELECTRODES AND CONDUCTIVE TRACES; from U.S. Provisional Application Ser. No. 62/832,101 filed Apr. 10, 2019 and entitled SYSTEMS AND METHODS FOR MAINTAINING MOISTURE IN A TEXTILE ELECTRODE; and from U.S. Provisional Application Ser. No. 62/832,104 filed Apr. 10, 2019 and entitled HYBRID YARN FOR WEAVING CONDUCTIVE WIRES INTO FABRIC. The contents of U.S. Provisional Application Ser. No. 62/832,098, U.S. Provisional Application Ser. No. 62/832,104, and U.S. Provisional Application Ser. No. 62/832,101 are hereby incorporated in their entireties by reference. The subject matter of this patent application may be related to the subject matter of U.S. patent application Ser. No. 16/845,772 entitled KNITTED TEXTILES WITH CONDUCTIVE TRACES OF A HYBRID YARN AND METHODS OF KNITTING THE SAME filed on Apr. 10, 2020, and U.S. patent application Ser. No. 16/845,796 entitled MACHINE-KNITTABLE CONDUCTIVE HYBRID YARNS, filed Apr. 10, 2020. Each of these patent applications is hereby incorporated herein by reference in its entirety.
This invention was made with Government support under Grant No. N00189-17-C-Z023 awarded by the U.S. Navy. The Government has certain rights in the invention.
Number | Name | Date | Kind |
---|---|---|---|
3472289 | Riordan et al. | Oct 1969 | A |
4262480 | Wasserman et al. | Apr 1981 | A |
4640689 | Sibalis | Feb 1987 | A |
4868580 | Wade | Sep 1989 | A |
4926910 | Wade | May 1990 | A |
5193607 | Demukai et al. | Mar 1993 | A |
5288289 | Haak et al. | Feb 1994 | A |
5927060 | Watson | Jul 1999 | A |
6941775 | Sharma | Sep 2005 | B2 |
7133227 | Chiang et al. | Nov 2006 | B2 |
7308294 | Hassonjee et al. | Dec 2007 | B2 |
7319895 | Klefstad-Sillonville et al. | Jan 2008 | B2 |
7592276 | Hill et al. | Sep 2009 | B2 |
7779656 | Dias et al. | Aug 2010 | B2 |
8060175 | Rowlandson et al. | Nov 2011 | B2 |
8214008 | Hassonjee et al. | Jul 2012 | B2 |
8283563 | Harris et al. | Oct 2012 | B2 |
8505474 | Kang et al. | Aug 2013 | B2 |
8934957 | Dias et al. | Jan 2015 | B2 |
9186092 | Mestrovic et al. | Nov 2015 | B2 |
9388514 | Roh | Jul 2016 | B2 |
9801583 | Derchak et al. | Oct 2017 | B2 |
10011925 | Kurahashi et al. | Jul 2018 | B2 |
10070815 | Shoshani et al. | Sep 2018 | B2 |
10144193 | Haraikawa et al. | Dec 2018 | B2 |
10155274 | Robinson et al. | Dec 2018 | B2 |
10299520 | Shaffer et al. | May 2019 | B1 |
10301751 | Dias et al. | May 2019 | B2 |
10448680 | Howland | Oct 2019 | B2 |
10462898 | Longinotti-Buitoni et al. | Oct 2019 | B2 |
10480104 | Fu et al. | Nov 2019 | B2 |
10480106 | Krajewski et al. | Nov 2019 | B2 |
10485103 | Sunshine et al. | Nov 2019 | B1 |
10492302 | Karagozler et al. | Nov 2019 | B2 |
10503339 | Karagozler | Dec 2019 | B2 |
10519575 | Thompson et al. | Dec 2019 | B2 |
10577732 | Podhajny et al. | Mar 2020 | B1 |
10754486 | Cobanoglu et al. | Aug 2020 | B2 |
20040057176 | Dhawan et al. | Mar 2004 | A1 |
20050034485 | Klefstad-Sillonville et al. | Feb 2005 | A1 |
20050231207 | Goldwater et al. | Oct 2005 | A1 |
20060218778 | Jawahar et al. | Oct 2006 | A1 |
20070083096 | Paradiso | Apr 2007 | A1 |
20070281155 | Tao et al. | Dec 2007 | A1 |
20080044652 | Krans et al. | Feb 2008 | A1 |
20080282665 | Speleers | Nov 2008 | A1 |
20090018428 | Dias et al. | Jan 2009 | A1 |
20100084179 | Harris et al. | Apr 2010 | A1 |
20100199901 | Kang et al. | Aug 2010 | A1 |
20110132040 | Jahn et al. | Jun 2011 | A1 |
20120100386 | Honma et al. | Apr 2012 | A1 |
20120225275 | Honma et al. | Sep 2012 | A1 |
20130172722 | Ninane et al. | Jul 2013 | A1 |
20130302605 | Yang et al. | Nov 2013 | A1 |
20140039292 | Su | Feb 2014 | A1 |
20140223650 | Hines et al. | Aug 2014 | A1 |
20140262478 | Harris et al. | Sep 2014 | A1 |
20140363656 | Kunisada et al. | Dec 2014 | A1 |
20150087925 | Pedley et al. | Mar 2015 | A1 |
20150297135 | Shoshani et al. | Oct 2015 | A1 |
20160018274 | Seitz | Jan 2016 | A1 |
20160145776 | Roh | May 2016 | A1 |
20160284436 | Fukuhara et al. | Sep 2016 | A1 |
20170073172 | Kuijpers et al. | Mar 2017 | A1 |
20170079348 | Chahine et al. | Mar 2017 | A1 |
20170107647 | Riethmuller et al. | Apr 2017 | A1 |
20170232538 | Robinson et al. | Aug 2017 | A1 |
20170275789 | Dias et al. | Sep 2017 | A1 |
20180042551 | Gouthez et al. | Feb 2018 | A1 |
20180073172 | Kurahashi et al. | Mar 2018 | A1 |
20180085060 | Shoshani et al. | Mar 2018 | A1 |
20180087191 | Threlkeld | Mar 2018 | A1 |
20180151795 | Cobanoglu et al. | May 2018 | A1 |
20180195210 | Sunshine et al. | Jul 2018 | A1 |
20180195218 | Hamada et al. | Jul 2018 | A1 |
20180195985 | Nebuya | Jul 2018 | A1 |
20180249767 | Begriche et al. | Sep 2018 | A1 |
20180258562 | Fukuhara | Sep 2018 | A1 |
20180279930 | Coppede et al. | Oct 2018 | A1 |
20190003083 | Carlsson et al. | Jan 2019 | A1 |
20190055678 | Hightower et al. | Feb 2019 | A1 |
20190156972 | Kondo et al. | May 2019 | A1 |
20190167192 | Frouin et al. | Jun 2019 | A1 |
20190354242 | Cobanoglu et al. | Nov 2019 | A1 |
20200123689 | Zhang et al. | Apr 2020 | A1 |
20200199790 | Hayashi | Jun 2020 | A1 |
20200270775 | Oppenheim | Aug 2020 | A1 |
20200325603 | King et al. | Oct 2020 | A1 |
20200345083 | Threlkeld | Nov 2020 | A1 |
20200347527 | Konukoglu et al. | Nov 2020 | A1 |
20210207294 | Threlkeld | Jul 2021 | A1 |
20210277544 | King et al. | Sep 2021 | A1 |
Number | Date | Country |
---|---|---|
105209673 | Dec 2015 | CN |
0458343 | Nov 1991 | EP |
532468 | Mar 1993 | EP |
1482079 | Jul 2007 | EP |
3090082 | Nov 2017 | EP |
3061851 | Jul 2018 | FR |
2082017 | Apr 2018 | SK |
2001002052 | Jan 2001 | WO |
2004097089 | Nov 2004 | WO |
WO2009013704 | Jan 2009 | WO |
2014138204 | Sep 2014 | WO |
2014165997 | Oct 2014 | WO |
2015022671 | Feb 2015 | WO |
2017095861 | Jun 2017 | WO |
2017111687 | Jun 2017 | WO |
2018020169 | Feb 2018 | WO |
WO2018020169 | Feb 2018 | WO |
2018128584 | Jul 2018 | WO |
2019134031 | Jul 2019 | WO |
2019143694 | Jul 2019 | WO |
2019145891 | Aug 2019 | WO |
Entry |
---|
U.S. Appl. No. 16/845,772, filed April 10, 2020, Knitted Textiles with Conductive Traces of a Hybrid Yarn and Methods of Knitting the Same. |
U.S. Appl. No. 16/845,796, filed Apr. 10, 2020, Machine-Knittable Conductive Hybrid Yarns. |
International Search Report and Written Opinion for International Application No. PCT/US2020/027697, dated Jul. 9, 2020 (14 pages). |
International Search Report and Written Opinion for International Application No. PCT/US2020/027699, dated Jul. 9, 2020 (13 pages). |
International Search Report and Written Opinion for International Application No. PCT/US2020/027695, dated Jul. 23, 2020 (13 pages). |
Weder, et al. Embroidered Electrode with Silver/Titanium Coating for Long-Term ECG Monitoring. Sensors 15, pp. 1750-1759, 2015. Retrieved from the Internet under https://www.mdpl.com/1424-8220/15/1/1750 on Mar. 23, 2020. |
International Preliminary Report on Patentability for International Application No. PCT/US2020/027695, dated Sep. 28, 2021 (11 pages). |
International Preliminary Report on Patentability for International Application No. PCT/US2020/027697, dated Sep. 28, 2021 (8 pages). |
International Preliminary Report on Patentability for International Application No. PCT/US2020/027699, dated Sep. 28, 2021 (11 pages). |
Supplementary European Search Report for EP Application No. 20787834.9, PCT/US2020027695 dated May 22, 2023 (9 pages). |
Lee et al. “Knit Band Sensor for Myoelectric Control of Surface EMG-Based Prosthetic Hand” IEEE Sensors Journal, vol. 18, No. 20, Oct. 15, 2018, pp. 8578-8586. |
No Author Listed “Kevlar Aramid Fiber Technical Guide” Dupont. Retrieved from the internet on Jul. 6, 2022 under https://www.dupont.com/content/dam/dupont/amer/US/en/safety/public/documents/en/Kevlar_Technical_Guide_0319.pdf (24 pages). |
No Author Listed “Twaron—a versitile high-performance fiber” Teijin Aramid. Retrieved from the internet on Jul. 6, 2022 under https://www.teijinaramid.com/wp-content/uploads/2016/07/Product-Brochure-Twaron.pdf (7 pages). |
Norholt, M. (1989). The Structure and Properties of Aramid Fibres. In: Bunsell, A.R., Lamicq, P., Massiah, A. (eds) Developments in the Science and Technology of Composite Materials. Springer, Dordrecht, Chapter 44, 2 pages. |
Supplementary European Search Report for EP Application No. 20786809.2 dated Nov. 21, 2022 (8 pages). |
Supplementary European Search Report for EP Application No. 20787051.0 dated Apr. 25, 2023 (11 pages). |
Number | Date | Country | |
---|---|---|---|
20200323491 A1 | Oct 2020 | US |
Number | Date | Country | |
---|---|---|---|
62832101 | Apr 2019 | US | |
62832104 | Apr 2019 | US | |
62832098 | Apr 2019 | US |