Wearable artificial jaw

Abstract

An artificial gill garment (100) is provided for providing oxygen to a wearer in an aquatic environment. The artificial gill garment includes a membrane (110) configured to permit the permeation of air through the membrane while preventing the permeation of water through the membrane. The membrane is configured to provide an air reservoir. Also provided is a method of manufacturing the artificial gill garment. [Selected figure] Figure 2A

Description

[Technical field]

[0001] The present invention relates to an artificial gill covering, a method for making an artificial gill covering, a precursor composition for making a gas-permeable waterproof membrane, and a method for making a gas-permeable waterproof membrane. [Background technology]

[0002] Environmental changes caused by human activities include rising sea levels and partial or total flooding of coastal cities, while the amount of land available for building is continually decreasing to accommodate a growing world population. Many countries and cities are preparing for these potentially dramatic changes by developing aquatic habitats on or underwater (and for exploiting the marine environment more generally).

[0003] The Netherlands, for example, is experimenting with cities built on water (see "A Dutch Architect Offshores the Future of Housing", www.nytimes.com). Amphibious hotels are being built on resort beaches (see "Underwater hotel room opens off the cost of Zanzibar", www.dezeen.com). The Japanese company Shimizu Corporation aims to build a floating city in Tokyo Bay and the equatorial zone this century (see "The Botanical Future City Concept of a Plant-like City", www.shimz.co.jp).

[0004] In such potentially submerged urban areas, the surrounding water can be exploited: below a depth of approximately 10 metres, there is enough oxygen available for human consumption, light is transparent enough to allow humans to see, and the water pressure is tolerable for repeated human dives.

[0005] Some aquatic insects have evolved to breathe in an aquatic environment. This can be achieved by several insects utilizing a porous superhydrophobic layer or its surface. When the surface is submerged, a thin air layer (i.e., gas gills) forms on the insect's body such that the superhydrophobic surface acts as an air retainer. The thin air layer also serves as a gas exchange interface with the surrounding water. When oxygen in the thin air layer is depleted, oxygen dissolved in the surrounding water can flow through the superhydrophobic layer into the thin air layer to compensate for the oxygen concentration difference between the thin air layer and the surrounding water. Similarly, when too much carbon dioxide exhaled by the insect remains in the thin air layer, the excess carbon dioxide can pass through the superhydrophobic layer and dissolve into the surrounding water, neutralizing the carbon dioxide concentration difference between the thin air layer and the surrounding water. This mechanism of gas exchange is known as plastron respiration.

[0006] Also, nitrogen in the thin air layer can diffuse from the thin air layer through the superhydrophobic layer and dissolve into the surrounding water. However, there is very little nitrogen dissolved in the water, and the partial pressure deficit caused by the transfer of nitrogen from the thin air layer to the surrounding water is compensated by the increased transfer of oxygen from the surrounding water to the thin air layer through the superhydrophobic layer. Figure 1 shows this in detail ("Physical gills in diving insects and spiders: theory and experiment", RS Seymour and PGD Matthews, Journal of Experimental Biology, 2013, 216, 164-170). The effective boundary layer shows a hypothetical layer of stagnant (i.e., non-flowing) water with a thickness L and surface area A that is necessary for the insect to achieve the necessary gas exchange by diffusion alone. The hydraulic boundary layer shows the distribution of the water flow velocity around the superhydrophobic layer. This flow velocity decreases as the distance from the outer surface of the thin air layer decreases. Summary of the Invention

[0007] According to a first aspect of the present invention, there is provided an artificial gill garment for providing oxygen to a wearer in an aquatic environment, the artificial gill garment comprising a membrane configured to permit permeation of air through the membrane and prevent permeation of water through the membrane, the membrane may be configured to provide an air reservoir.

[0008] The membrane may be configured to provide an air reservoir directly between the membrane and the wearer, for example, in a single layer on the wearer's skin. Alternatively, the membrane may be configured to provide an air reservoir between multiple surfaces of the membrane. For example, the membrane may provide or encapsulate an air reservoir between multiple layers or surfaces thereof. The membrane may effectively provide a sealed container or reservoir for air in use.

[0009] By providing an air reservoir within the artificial gill garment with a membrane configured to allow air to penetrate without allowing water to penetrate for the user to breathe, the artificial gill garment may allow the wearer to breathe underwater for extended periods of time, or indefinitely. The permeation of air through the membrane of the artificial gill garment may allow oxygen gas dissolved in the surrounding water to permeate the membrane and provide oxygen for the wearer to breathe. At the same time, the membrane may allow exhaled carbon dioxide to permeate the membrane and dissolve in the surrounding water. In this manner, an optimal breathing environment may be maintained within the artificial gill garment.

[0010] Thus, the artificial gill covering may enable the wearer to remain underwater for longer than would normally be achievable while free diving (i.e., diving where the diver holds his / her breath and does not require any equipment) without the heavy and bulky equipment normally required for scuba diving or deep sea diving, and may enable the wearer to swim at greater depths than would normally be achievable while snorkeling, without the heavy additional equipment required for oxygen breathing, and without the risk of water being forced into the snorkeling mask via the breathing tube.

[0011] The membrane may comprise a mask portion in fluid communication with the air reservoir and configured to cover at least the respiratory features of the wearer's face. The mask portion may be or include a recess or shell shaped to fit or seal with the wearer's face. The seal may be similar to known snorkeling / diving mask seals (flexible materials such as rubber or silicone). The membrane may be attached or attachable to the mask portion. The membrane may be positioned over or configured to cover at least a portion of the wearer's body, for example, part or all of the wearer's torso, or part or all of one or more non-torso areas (limbs) of the wearer. The surface area of ​​the artificial gill garment may be modified according to the wearer's respiratory needs. The artificial gill garment may also be modified according to the wearer's personal preference, for example, for a garment with long or short sleeves or legs.

[0012] The mask portion may be formed from or include a plastic or polymeric material, such as acrylonitrile butadiene styrene (ABS), polycarbonate, or any other suitable underwater mask material. The mask portion may be rigid, semi-rigid, or flexible, in whole or in part. The mask portion may include a flexible or sealing material around its edges to form a fluid-tight seal when in use by a wearer.

[0013] The membrane may be formed from or include a flexible material, which may allow for unconstrained, natural movement of the wearer, both in the water and on land, and thus improve comfort for the wearer in situations where the wearer may make multiple dives in a short period of time.

[0014] The membrane may be or may include a porous hydrophobic or superhydrophobic material. The porous hydrophobic or superhydrophobic material may include at least one of porous thermoplastic polyurethane, polydimethylsiloxane, polybutadiene, polyester, neoprene or other polymeric material, or plastic. The porous hydrophobic material may have a porosity of 20 to 80% by volume.

[0015] Polydimethylsiloxane can be a useful membrane material for deep sea diving clothing because of its high resistance to tearing.

[0016] The porous thermoplastic polyurethane may have a porosity of 20-80% by volume. For example, a higher porosity would allow for a higher gas exchange rate, allowing the artificial gill garment to be utilized in shallow waters where water pressure is low and therefore less likely to seep through the membrane. A garment comprising a material with easily controllable porosity may allow for the manufacture of different garments with a wide range of different porosities for a wide range of underwater applications.

[0017] The hydrophobic material may allow the wearer to remain dry, for example, on land. In one embodiment, since the artificial gill garment includes a waterproof membrane, the wearer's body part enclosed within the artificial gill garment may remain dry even in water. Also, since the hydrophobic material repels water on the surface of the artificial gill garment, the artificial gill garment may remain dry when the wearer is on land. In contrast to many typical free diving or scuba diving garments, the increase in weight of the artificial gill garment due to water retention is countered. Thus, the comfort of the wearer may be improved (i.e., compared to conventional diving equipment or garments such as wet suits) in situations where the wearer may make multiple dives in a short period of time.

[0018] The porous hydrophobic material may include a hydrophobic coating. The hydrophobic coating may include a fluoroalkyl-based polymeric hydrophobic coating. The fluoroalkyl-based polymeric hydrophobic coating may be and / or include perfluoropolyether, perfluoroalkoxy polymer, perfluoroelastomer, polytetrafluoroethylene, perfluorosulfonic acid, polyhalogenated hydrocarbon polymer, polypropylene, or polytetrafluoroethylene.

[0019] The membrane or the outer surface of the membrane may include a surface pattern and / or surface shape or configuration to increase the surface area of ​​the outer surface. Increasing the surface area of ​​the artificial gill covering may allow more effective penetration of oxygen and carbon dioxide through the membrane, thus more efficiently meeting the respiratory needs of the wearer by providing a sufficient amount of fresh oxygen (and removing a sufficient amount of exhaled carbon dioxide) at a sufficient rate so that the wearer can breathe properly underwater.

[0020] The increased surface area may be provided in the outer surface by one or more undulations, folds, pockets, creases, pleats, etc. The material of the membrane or the material of the outer surface of the membrane may be selected to withstand a particular water pressure corresponding to a particular diving depth.

[0021] The artificial gill garment may include a rebreather. The rebreather may be configured to extract carbon dioxide from the wearer's breath exhaled into the air reservoir. The rebreather may be configured to allow the wearer to rebreathe unused oxygen during exhalation. If the surface area of ​​the artificial gill garment is not large enough to provide enough oxygen for the wearer to breathe without an additional oxygen supply, or if the oxygen in the space is depleted, for example on a long dive, the rebreather may be used to allow the artificial gill garment to meet the breathing needs of the wearer.

[0022] The artificial gill covering may include an oxygen tank configured to store oxygen and supply oxygen to the air reservoir. If the surface area of ​​the artificial gill covering is not large enough to provide enough oxygen for the wearer to breathe without additional oxygen supply, an oxygen tank may be used to allow the artificial gill covering to fill the wearer's breath. The artificial gill covering may provide only a percentage of the oxygen required for the wearer to breathe (e.g., 10% to 100%), and the oxygen tank may provide the remaining oxygen (e.g., 90% to 0%) as needed, depending on the gas permeability characteristics of the artificial gill covering. Thus, the oxygen tank may have a smaller capacity than oxygen tanks typically used for scuba diving or deep sea diving.

[0023] According to a second aspect of the present invention, there is provided a method for producing a membrane and / or an artificial gill covering. The method may be used to produce the membrane and / or the artificial gill covering of the first aspect. The method may comprise three-dimensional printing the artificial gill covering into a desired garment shape. The printed garment is air permeable and water impermeable (waterproof). The three-dimensional printing may utilise additive manufacturing (3D printing) techniques. The method may comprise three-dimensional printing of fibres into the desired garment shape, powder-based three-dimensional printing, and / or liquid or paste-based three-dimensional printing. Alternatively, the artificial gill covering may be cast. The method may be used to produce the artificial gill covering according to the first aspect of the present invention.

[0024] Three-dimensional printing of artificial gill garments may allow for the design and manufacture of complex shapes that may be more difficult or impossible to manufacture using other manufacturing methods. In particular, three-dimensional printing may allow for the manufacture of garments with complex shaped outer surfaces to increase the surface area of ​​the outer surfaces. Three-dimensional printing may also be used to manufacture one-piece garments. One-piece garments may reduce or eliminate the risk of water ingress into the space between the artificial gill garment and the wearer at the joining locations of the multi-piece garment underwater.

[0025] The method may include forming one or more air permeable and water impermeable regions in the printed garment, for example by creating pores using three dimensional printing to form the one or more air permeable and water impermeable regions.

[0026] The fibers may include composite fibers of hydrophobic and hydrophilic materials. The hydrophobic material may be or include a hydrophobic elastomeric polymer. The hydrophilic material may include hydrophilic particles. The hydrophobic elastomeric polymer may include at least one of thermoplastic polyurethane, polybutadiene, polydimethylsiloxane, neoprene, polyester, and / or any other polymeric plastic or material. The hydrophilic particles may include at least one of polyvinyl alcohol, crystalline salt, and polyglycolic acid. The method may further include washing the printed garment with water to remove the hydrophilic material from the printed garment.

[0027] By utilizing fibers containing a composite of hydrophobic and hydrophilic materials for 3D printing, the porosity of the printed garment can be easily and delicately controlled by varying the composition of the fibers. Thus, a wide range of garments suitable for different underwater applications can be produced. The malleability of the material advantageously provides for producing waterproof "container" type garments.

[0028] The fiber may be or may contain a composite fiber of thermoplastic polyurethane and polyvinyl alcohol. The weight ratio of the thermoplastic polyurethane to the polyvinyl alcohol in the composite fiber may be 20:80 to 80:20. The weight ratio of the thermoplastic polyurethane to the polyvinyl alcohol in the composite fiber may be 30:70 to 70:30, or even 40:60 to 60:40.

[0029] The method may further include coating the printed garment with a hydrophobic or superhydrophobic coating. The method may further include coating the printed garment with a fluoroalkyl-based polymeric hydrophobic coating. The fluoroalkyl-based polymeric hydrophobic coating may be or include one or more of perfluoropolyether, perfluoroalkoxy polymer, perfluoroelastomer, polytetrafluoroethylene, or perfluorosulfonic acid.

[0030] The hydrophobic coating may allow the wearer to stay dry, for example, on land. Because the artificial gill clothing includes a waterproof membrane, the part of the wearer's body that is enclosed within the artificial gill clothing may stay dry even in water. Also, because the hydrophobic coating repels water on the surface of the artificial gill clothing, the artificial gill clothing may be able to stay dry when the wearer is on land. In contrast to many typical free diving or scuba diving clothing, the weight gain of the artificial gill clothing due to water retention may be countered. Thus, the comfort of the wearer may be improved in situations where the wearer may perform multiple dives in a short period of time.

[0031] According to a third aspect of the invention, a precursor composition for making a gas-permeable waterproof membrane may be provided. The precursor composition comprises a mixture of a hydrophobic material and a hydrophilic material. The precursor composition may be used to make the artificial gill garment of the first aspect of the invention or may be used in the method of the second aspect of the invention. The hydrophobic material may be or may include a hydrophobic elastomeric polymer.

[0032] The hydrophilic material may be or may include hydrophilic particles. The hydrophobic elastomeric polymer may include at least one of thermoplastic polyurethane, polybutadiene, polydimethylsiloxane, neoprene, polyester, and / or any other polymeric plastic or material. The hydrophilic particles may include at least one of polyvinyl alcohol, crystalline salt, and polyglycolic acid. The mixture may include thermoplastic polyurethane and polyvinyl alcohol such that the weight ratio of thermoplastic polyurethane to polyvinyl alcohol is 20:80 to 80:20. The weight ratio of thermoplastic polyurethane to polyvinyl alcohol in the mixture may be 30:70 to 70:30, and may further be 40:60 to 60:40.

[0033] According to a fourth aspect of the present invention, there is provided a gas-permeable waterproof membrane produced using the precursor composition according to the third aspect of the present invention. The gas-permeable waterproof membrane may be the gas-permeable waterproof membrane according to the first aspect.

[0034] According to a fifth aspect of the present invention, there is provided a method for producing a gas-permeable waterproof membrane. The gas-permeable waterproof membrane may be the gas-permeable waterproof membrane according to the first or fourth aspect. The method includes producing a mixture of hydrophobic and hydrophilic materials. The method further includes forming a membrane from the mixture of hydrophobic and hydrophilic materials. The method also includes washing the membrane in water to remove hydrophilic material from the membrane, thereby creating pores in the membrane. The method may be used to produce an artificial gill covering according to the first aspect of the present invention.

[0035] The method may further include treating the surface of the membrane to impart hydrophobic properties to the surface of the membrane.

[0036] Treating the surface of the membrane may include coating the surface of the membrane with a hydrophobic coating. The hydrophobic coating may include a fluoroalkyl-based polymeric hydrophobic coating. Alternatively, treating the surface of the membrane may include altering the surface chemistry of the membrane surface by reacting a material on the surface of the membrane with one or more substances.

[0037] The hydrophobic material may be or may include a hydrophobic elastomeric polymer. The hydrophilic material may be or may include a hydrophilic particle. The hydrophobic elastomeric polymer may be or may include at least one of thermoplastic polyurethane, polybutadiene, polydimethylsiloxane, neoprene, polyester, and / or any other polymeric plastic or material. The hydrophilic particle may be or may include at least one of polyvinyl alcohol, crystalline salt, and polyglycolic acid. The mixture may include a thermoplastic polyurethane and a polyvinyl alcohol such that the weight ratio of the thermoplastic polyurethane to the polyvinyl alcohol is 20:80 to 80:20. The weight ratio of the thermoplastic polyurethane to the polyvinyl alcohol in the mixture may be 30:70 to 70:30, and may further be 40:60 to 60:40.

[0038] In a sixth aspect, there is provided a garment comprising a gas-permeable waterproof membrane produced by the method of any of the fifth aspect.

[0039] In a seventh aspect, there is provided a building or structure comprising a gas-permeable waterproof membrane produced by the method of any of the fifth aspect.

[0040] In the first, second, fourth, fifth, sixth and seventh aspects of the invention, the pore size may be about 250 micrometers or less in all directions, and optionally about 100 micrometers or less in all directions. Such pore size is optimal for balancing gas permeability and waterproofness provided by the hydrophobic or superhydrophobic properties of the membrane. The porosity of the membrane may be 20% to 80%, optionally 30% to 70%, and even more optionally 40% to 60%. The porosity of the membrane can be tailored to suit a particular application. For example, shallow diving has lower water pressure, so the membrane may have a higher porosity to provide gas permeability through the membrane.

[0041] Features described in the context of separate aspects and / or embodiments of the invention may be used together or may be interchangeable where possible. Similarly, features that are described for brevity in the context of a single embodiment or aspect may also be provided separately or in any suitable subcombination. Features described in the context of an artificial gill covering or membrane may have corresponding features that can be defined in the context of a method, and vice versa, and these embodiments are specifically envisaged. [Brief description of the drawings]

[0042] The invention will now be described, by way of example only, with reference to the accompanying drawings in which: [Figure 1] FIG. 1 shows a schematic diagram of plastron respiration in aquatic insects. [Figure 2-1] 2A, 2B, and 2C show front, side, and back views, respectively, of an artificial gill garment in one embodiment. [Figure 2-2] 2D, 2E, and 2F show front, side, and back views, respectively, of an artificial gill garment in another embodiment. [Diagram 3] FIG. 3 shows a schematic of oxygen and carbon dioxide gas exchange through an artificial gill covering according to the present disclosure. [Figure 4]FIG. 4 shows the surface configuration of the artificial gill garment according to the present disclosure. [Diagram 5] 5A-5E show various components of an experimental setup for investigating the gas exchange properties of a porous superhydrophobic membrane according to the present disclosure. [Figure 6] FIG. 6 shows a plot of oxygen concentration as a function of time in an experiment performed using the experimental setup of FIG. [Figure 7] 7A and 7B show optical microscope images of a porous membrane according to the present disclosure. [Figure 8] FIG. 8 shows a plot of oxygen concentration as a function of time for an experiment conducted using the experimental setup of FIG. 5 performed on the porous membrane shown in FIGS. 7A and 7B. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0043] Features described in the context of separate aspects and embodiments of the invention may be used together or may be interchangeable where possible. Similarly, features are described in the context of a single embodiment for brevity, but they may be provided separately or in any suitable subcombination. Features described in the context of an artificial gill garment may have corresponding features that can be defined in the context of a method for producing the composition, and these embodiments are specifically contemplated.

[0044] 2A-2F show an artificial gill garment 100 according to one embodiment of the present invention. The artificial gill garment 100 is designed to be worn by a wearer and is configured to support underwater breathing and provide comfortable clothing both underwater and out of water. For example, the artificial gill garment 100 may be particularly suitable for individuals who frequently dive in shallow waters as part of their daily lives. The artificial gill garment 100 does not necessarily need to be removed after diving and can be worn on land as well as underwater.

[0045] The artificial gill garment 100 comprises a mask portion 105 and a membrane or body portion 110. The mask portion 105 is configured to cover the respiratory features of the wearer's face (i.e., mouth and / or nose). The body portion 110 is configured to cover at least the wearer's torso. In some examples, the body portion 110 may be configured to cover the wearer's torso and one or more limbs (i.e., arms or legs). In other examples, the body portion 110 may be configured to cover a smaller percentage of the wearer's body than the wearer's torso and limbs, for example, the wearer's shoulders and upper torso. In other examples, the artificial gill garment 100 may be configured to cover the wearer's entire head and / or may not include the body portion 110.

[0046] In one embodiment, the artificial gill garment 100 may be manufactured to ensure a secure fit around the wearer at one or more potential points of water ingress. For example, the artificial gill garment 100 may be manufactured to ensure a secure fit around the wearer's face, and optionally around the wearer's shoulders, elbows, wrists, or other points on any of the arms, depending on the length of the garment. Similarly, the artificial gill garment 100 may be manufactured to ensure a secure fit around the wearer's waist, thighs, calves, ankles, or other points on the legs, depending on the length of the garment. The artificial gill garment 100 may be manufactured to ensure a secure fit around the wearer's neck and face, for example, by placing or sealing a mask around the wearer's face or head. The artificial gill garment 100 may be configured to fit securely around the wearer at potential points of water ingress by manufacturing relevant portions of the artificial gill garment 100 such that, at such potential points of water ingress, the wearer must stretch the artificial gill garment 100 over himself when donning the artificial gill garment 100. Elastic deformation of the artificial gill garment 100 at such points of the artificial gill garment 100 may allow the wearer to don the artificial gill garment 100, and the subsequent elastic response of the artificial gill garment 100 may cause the artificial gill garment 100 to contract around the wearer's body at the potential points of water ingress, thereby ensuring that the artificial gill garment 100 forms a seal around the wearer.

[0047] Alternatively, the artificial gill garment 100 may include a seal configured to prevent the ingress of water at a potential point of water ingress where a hole is formed to allow the wearer to wear the artificial gill garment 100.

[0048] In one embodiment shown in Figures 2A-2C, the mask portion 105 and the main body portion 110 are configured together to form a space between the artificial gill garment 100 and the wearer. Air trapped between the artificial gill garment 100 and the wearer circulates within the interior space between the wearer and the artificial gill garment 100, thereby allowing the wearer to breathe while wearing the artificial gill garment 100 underwater. In this embodiment, the artificial gill garment 100 comprises a single layer membrane configured to allow air to permeate through the membrane but prevent water from permeating through the membrane.

[0049] In different embodiments shown in Figures 2D-2F, an air reservoir 111 is provided between the layers 110, 110' or surfaces of the body portion 110. For example, the air reservoir 111 may be formed within a bilayer membrane or within an envelope 110 (e.g., formed by enclosing or folding the membrane 110 on itself). Figures 2D-2F show the air reservoir 111 in this embodiment by dashed lines 110, 110'.

[0050] In either embodiment, the artificial gill garment 100 is configured to replenish the wearer's supply of fresh oxygen for breathing while the wearer is wearing the artificial gill garment 100 underwater. A depletion of oxygen concentration in the space between the artificial gill garment 100 and the wearer or between the layers of the artificial gill garment 100 as a result of the wearer's breathing causes an oxygen concentration difference between the air in the air reservoir 111 and the surrounding water. This concentration difference acts as a driving force to force oxygen gas dissolved in the surrounding water to permeate through the membrane and enter the air reservoir 111 between the artificial gill garment 100 and the wearer or between the layers of the artificial gill garment 100. Similarly, an increase in carbon dioxide concentration in the air reservoir 111 as a result of the wearer's breathing causes a carbon dioxide concentration difference between the air in the air reservoir 111 and the surrounding water. This concentration difference acts as a driving force to force carbon dioxide in the air reservoir 111 to permeate through the membrane and dissolve in the surrounding water (according to Fick's first law of diffusion). In this way, the air composition in the air reservoir 111 can be kept at an optimum composition for the wearer to breathe. Figure 3 shows this process diagrammatically.

[0051] The membrane 110 (or 110, 110') is or includes an at least partially flexible material to allow the wearer to move naturally while wearing the artificial gill garment 100 both in water and on land. Alternatively, the membrane 110 (or 110, 110') may include a rigid material, for example to accommodate increased water pressure with increasing depth or to protect the wearer from rough underwater conditions or attacks from marine life. Garments including rigid materials may also be useful, for example, in military applications.

[0052] The membrane 110 (or 110, 110') may comprise a porous hydrophobic or superhydrophobic material. The porous hydrophobic or superhydrophobic material allows air to permeate through the membrane 110 (or 110, 110') while improving the impermeability of the membrane 110 (or 110, 110') to water. The hydrophobic or superhydrophobic material also allows the wearer to stay dry while wearing the artificial gill garment 100 because water is not retained in or on the surface of the material. The fact that the artificial gill garment 100 does not retain water also means that the artificial gill garment 100 does not change weight after use in water, a common problem with typical diving equipment. This allows the wearer to wear the artificial gill garment 100 comfortably multiple times in succession since there is no need to dry it after use.

[0053] The porous hydrophobic or superhydrophobic material may include a porous thermoplastic polyurethane (TPU), the porosity of which may be 20-80% by volume.

[0054] The porous hydrophobic or superhydrophobic material may include a fluoroalkyl-based polymer coating. The fluoroalkyl-based polymer coating may include at least one of perfluoropolyether, perfluoroalkoxy polymer, perfluoroelastomer, polytetrafluoroethylene, and perfluorosulfonic acid. The fluoroalkyl-based polymer coating may provide hydrophobic or superhydrophobic properties to prevent water penetration through the membrane 110 (or 110, 110').

[0055] The membrane 110 (or 110, 110') includes an outer surface having a surface or a surface pattern and / or a surface shape, or a structure configured to increase the surface area of ​​the surface / outer surface. The surface pattern or surface shape may be an undulating surface including multiple raised bands (e.g., multiple semi-cylindrical bands) on the outer surface of the artificial gill covering 100, as shown in Figures 4A and 4B (which show only the main body portion 110). Other surface patterns such as grooves, ridges, or depressions may be used to increase the surface area of ​​the outer surface of the artificial gill covering 100. The surface pattern may be a micropattern (e.g., including features having dimensions less than 1000 micrometers). The micropattern may be created by machining the surface of the artificial gill covering 100. The greater the surface area of ​​the outer surface of the artificial gill covering 100, the more effective (i.e., higher permeation rate) the oxygen and carbon dioxide will be permeating through the membrane into the space between the artificial gill covering 100 and the wearer. This allows the artificial gill garment 100 to supplement the supply of fresh oxygen to the wearer to meet the wearer's respiratory needs (i.e., by providing a sufficient amount of fresh oxygen so that the wearer can breathe properly). Also, as shown in Figures 4A and 4B, the surface shape / surface pattern configuration may act to increase the volume of the air reservoir 111. In the case of semi-cylindrical raised bands as shown in Figures 4A and 4B, each raised band may provide an additional air pocket within the air reservoir 111.

[0056] The artificial gill garment 100 shown in Figures 2A-2F includes a rebreather 120. The rebreather 120 is positioned on the back of the artificial gill garment 100 relative to the wearer, but may be positioned anywhere on the artificial gill garment 100. The rebreather 120 extracts carbon dioxide from the wearer's breath, allowing the wearer to utilize unused oxygen in the breath without inhaling carbon dioxide previously exhaled. Flow lines 115 indicate the direction of flow of the breath from the wearer's mouth or nose to the rebreather 120. The breath may flow from the mask portion 105 of the artificial gill garment 100 across the front of the artificial gill garment 100 toward the main body portion 110 of the artificial gill garment 100, then around the lateral sides of the artificial gill garment 100 and across the rear toward the rebreather 120. The breath may flow throughout the full air reservoir 111. Once the rebreather 120 extracts carbon dioxide from the exhaled air, rebreatherable air may flow from the rebreather 120 towards the mask portion 105 of the artificial gill garment 100 by flowing over the back of the body portion 110 around the neck and shoulders of the wearer, as shown by flow lines 125. Once the rebreatherable air reaches the mask portion 105, the wearer can breathe the rebreatherable air. The rebreather 120 is configured to cooperate with the membrane 110 (or 110, 110') to supply breathable air to the air reservoir 111.

[0057] Alternatively, the exhaled and / or rebreathable air may not follow any well-defined flow pattern within the air reservoir 111 but may instead diffuse randomly within the air reservoir 111 .

[0058] Alternatively or additionally, the artificial gill garment 100 may include an oxygen tank (not shown). The oxygen tank may be configured to provide supplemental oxygen to the air reservoir 111 to assist the wearer in breathing. The oxygen tank may be configured to provide supplemental oxygen in response to the oxygen concentration in the air reservoir 111 falling below a predetermined threshold. The oxygen concentration in the air reservoir 111 may be measured by an oxygen sensor disposed in the air reservoir 111. The oxygen tank may be configured to cooperate with the membrane 110 (or 110, 110') and / or the rebreather 120 to provide oxygen to the air reservoir 111.

[0059] Alternatively, the artificial gill garment 100 may not include a rebreather 120 or oxygen tank. The artificial gill garment 100 may be configured to have a surface area large enough to provide sufficient oxygen to the air reservoir 111 by oxygen permeation through the membrane 110 (or 110, 110') of the artificial gill garment 100.

[0060] The artificial gill garment 100 may be manufactured using various manufacturing techniques. For example, the artificial gill garment 100 may be manufactured using additive layer manufacturing techniques, such as three-dimensional printing (3D printing). Manufacturing the artificial gill garment 100 using additive layer manufacturing techniques allows the manufacture of complex shapes with high surface area, which may allow efficient air circulation in the air reservoir 111. Both characteristics are desirable for efficient gas exchange (i.e., oxygen and carbon dioxide) with the air reservoir 111 to maintain optimal breathing conditions for the wearer. Thanks to the 3D printability, the artificial gill garment 100 with a desired shape may be created using computer calculations and / or using parametric design. Alternatively, the artificial gill garment 100 may be manufactured using casting techniques. A mold for the casting process may be designed to impart a complex surface shape or surface pattern, which may give the artificial gill garment 100 a high surface area and efficient air circulation in the air reservoir. .

[0061] The artificial gill garment 100 may be 3D printed using powder-based 3D printing. The artificial gill garment 100 may be 3D printed using liquid or paste-based three-dimensional printing. The artificial gill garment 100 may be manufactured via 3D printing using fused deposition modeling technology (i.e., fused filament manufacturing). The fibers may include fibers of a porous or non-porous material. The fibers may include a single component material or a composite material. The fibers may include a hydrophobic or superhydrophobic material.

[0062] The fibers may include composite fibers of hydrophobic and hydrophilic materials. The hydrophobic material may be or may include a hydrophobic elastomeric polymer. The hydrophilic material may be or may include a hydrophilic particle. The hydrophobic elastomeric polymer may include at least one of thermoplastic polyurethane, polybutadiene, and polydimethylsiloxane, but other hydrophobic elastomeric polymer materials may be used. The hydrophilic particles may include at least one of polyvinyl alcohol, crystalline salt, and polyglycolic acid, but other hydrophilic particulate materials may be used. The fibers may include composite fibers of thermoplastic polyurethane (TPU) and polyvinyl alcohol (PVOH). The TPU:PVOH in the composite fiber may be approximately 20:80 to 80:20 by weight. Alternatively, the TPU:PVOH in the composite fiber may be approximately 30:70 to 70:30 by weight, or may further be approximately 40:60 to 60:40 by weight. The initial composition of the composite TPU and PVOH fibers determines the final porosity of the membrane of the artificial gill covering 100 (described below). The particle size of the PVOH particles used in the composite fiber determines the size of the pores created using the composite fibers of TPU and PVOH. Depending on the desired pore size (as larger pore sizes are more permeable), the particle size of the PVOH particles used in the composite fiber is preferably between 1 and 100 micrometers. The particle size of the TPU particles used in the composite fiber may be substantially equal to the particle size of the PVOH particles used in the composite fiber. The particle size of the TPU particles used in the composite fiber may be between 1 and 50 micrometers.

[0063] The fibers are then used to form the artificial gill garment 100 using 3D printing techniques. The advantage of 3D printing over casting is that a one-piece garment can be more easily manufactured without the need for further processing steps to join two or more separate parts (i.e., via sewing or otherwise gluing) to form a complete garment (as is the case with casting). Such post-manufacturing joining of separate components of the garment can reduce the ability of the artificial gill garment 100 to prevent the ingress of water into the space between the artificial gill garment 100 and the wearer if not joined correctly.

[0064] Compositions such as those described above for 3D printing of the artificial gill garment 100 may also be used to cast the artificial gill garment 100.

[0065] In the case of non-porous fiber materials or casting materials, further processing steps such as washing or etching may be required to produce an artificial gill garment 100 with a porous membrane 110 (or 110, 110') to allow gas transmission through the membrane 110 (or 110, 110') of the artificial gill garment 100. For example, if the fiber used to 3D print the artificial gill garment 100 is a composite fiber of hydrophobic elastomeric polymer and hydrophilic particles, the artificial gill garment 100 may be washed with distilled water or a mixture of distilled water and ethanol to remove the hydrophilic particles from the artificial gill garment 100. Removing the hydrophilic particles from the artificial gill garment 100 produces a porous artificial gill garment 100. The composition of the composite hydrophobic elastomeric polymer hydrophilic particle fiber used in 3D printing determines the final porosity of the membrane of the artificial gill garment 100. For example, a composite TPU:PVOH fiber with a higher weight ratio of TPU may have a lower final porosity after washing than a composite TPU:PVOH fiber with a lower weight ratio of TPU. Thus, because the densities of TPU and PVOH are similar, the porosity of the resulting material will be in the range of 80-20% by volume, respectively. The resulting pore size will depend on the particle size of the PVOH particles used in the composite fiber. Thus, the pore size can be controlled between 1-100 micrometers. After washing, the artificial gill garment 100 is left to dry in an ambient environment.

[0066] In some examples, the porosity of the artificial gill garment 100 may be introduced during the manufacture of the artificial gill garment 100 using 3D printing. For example, pores may be introduced into the artificial gill garment 100 by constructing features in the artificial gill garment 100 during 3D printing. As described above, the pore size of the artificial gill garment 100 may be approximately 100 micrometers or less. In this manner, the 3D printer may introduce porosity into the artificial gill garment 100 by constructing pores having dimensions of approximately 100 micrometers or less (e.g., diameters of approximately 100 micrometers or less) in all directions. In some examples, hydrophobic or superhydrophobic properties may be imparted to the artificial gill garment 100 by generating small-scale (e.g., micrometer length scale) surface patterns on the exterior surface of the artificial gill garment 100 during 3D printing.

[0067] The gas permeability (i.e., gas exchange ratio) of the membrane of the artificial gill clothing 100 in water varies depending on the thickness of the membrane and the porosity of the membrane 110 (or 110, 110'). For the composite TPU:PVOH fiber used in 3D printing of the artificial gill clothing 100, the initial composition of TPU:PVOH determines the porosity of the membrane 110 (or 110, 110') of the artificial gill clothing 100. Gas permeability is proportional to the porosity and inversely proportional to the membrane thickness. Thus, a thinner membrane 110 (or 110, 110') with a higher porosity will have a higher gas permeability than a thicker membrane with a lower porosity. However, a thicker membrane with a lower porosity will have a lower gas permeability under high water pressure than a thinner membrane with a higher porosity.

[0068] In the case of non-hydrophobic or non-superhydrophobic textile materials or casting materials, further processing steps may be required to produce the artificial gill garment 100 with hydrophobic or superhydrophobic properties. The artificial gill garment 100 may be treated by altering the surface chemistry of the artificial gill garment 100 to generate the hydrophobic properties of a superhydrophobic surface. The artificial gill garment 100 may be coated with a hydrophobic or superhydrophobic coating or exposed to a substance that reacts with the material of the printed garment to form an outer surface of the artificial gill garment 100 with hydrophobic or superhydrophobic properties. For example, if the fiber used to 3D print the artificial gill garment 100 is a TPU:PVOH composite fiber, the artificial gill garment 100 may be coated with a fluoroalkyl-based polymer coating to provide an outer surface of the artificial gill garment 100 with hydrophobic or superhydrophobic properties. The coating may have a thickness between 0.25 and 2 micrometers, optionally between 0.5 and 1 micrometer.

[0069] In addition, the fiber material used for 3D printing the artificial gill clothing 100 may be selected based on the mechanical properties required for the artificial gill clothing 100. For example, if the artificial gill clothing 100 is required to enable the wearer to move naturally without restriction, a fiber containing a flexible material may be used for 3D printing the artificial gill clothing 100. If the artificial gill clothing 100 is required to protect the wearer from rough underwater conditions or attacks by marine organisms, or if the artificial gill clothing 100 needs to withstand increased water pressure at deeper water depths, a fiber containing a semi-rigid or rigid material may be used for 3D printing the artificial gill clothing 100.

[0070] By manufacturing the artificial gill garment 100 according to the above-described method, it is possible to produce a water-repellent, gas-permeable garment that has the mechanical properties (i.e., flexibility, stiffness, strength, toughness) desired for the application of the artificial gill garment 100.

[0071] A gas-permeable waterproof membrane (not necessarily for use in an artificial gill garment) may be manufactured using a method similar to that described above with respect to the artificial gill garment 100. For example, a precursor composition for making a gas-permeable waterproof membrane may be manufactured by manufacturing a mixture of a hydrophobic elastomeric polymer (e.g., TPU) and hydrophilic particles (e.g., PVOH). A membrane may then be formed from the mixture of the hydrophobic elastomeric polymer and the hydrophilic particles. The membrane may be formed, for example, by 3D printing, casting, or other suitable manufacturing techniques. To remove the hydrophilic particles from the membrane, the membrane may be washed with distilled water to create pores in the membrane.

[0072] The surface of the membrane may also be treated to impart hydrophobic or superhydrophobic properties to the surface of the membrane.

[0073] In some instances, parts made from the precursor composition may be distributed to a third party prior to the cleaning or coating step. In this manner, the process for making the gas-permeable waterproof membrane or parts need not be produced at a single location or by a single manufacturer.

[0074] The gas-permeable waterproof membrane as produced by the above method may be used in underwater structures or buildings. For example, buildings may be created that contain underwater spaces within the spaces surrounded by the gas-permeable waterproof membrane, rather than artificial gill clothing. One or more people may be able to breathe within the spaces surrounded by the gas-permeable waterproof membrane. The gas-permeable waterproof membrane may also be used to filter harmful gases dissolved in water. 3D printing may enable the production of filters with complex shapes and shapes for use in environments or locations that are otherwise difficult to access using standard filter types and / or shapes. Other applications may include highly gas-permeable, water-repellent clothing for extreme sports.

[0075] To measure the gas exchange properties of the porous superhydrophobic material, an experimental setup as shown in FIG. 5 was used. A first opening 205 (shown from below) in the tank 200 was covered with a porous superhydrophobic membrane 210, and a liquid-tight seal was formed between the porous superhydrophobic membrane 210 and the edge of the first opening 205. FIG. 5A shows this in more detail. The porous superhydrophobic membrane 210 formed the only path through which gas could be exchanged with the inside of the tank 200. The porous superhydrophobic membrane was a polytetrafluoroethylene membrane with a thickness of 5 mm and a porosity of 77%. As shown in FIG. 5B, water droplets on the porous superhydrophobic membrane 210 indicate that water cannot pass through the porous superhydrophobic membrane 210. An oxygen sensor 215 was also placed in the tank 200. A tube 225 for introducing carbon dioxide gas into the tank 200 was passed through a second opening 220 in the tank 200, and a liquid-tight seal was formed between the tube 225 and the edge of the second opening 220. FIG. 5C shows this in more detail.

[0076] 5D and 5E, the completely sealed tank 200 was completely submerged in hydrogen peroxide (oxygen-saturated water) and kept underwater for the test period. After submersion in the hydrogen peroxide, carbon dioxide gas was introduced into the sealed tank 200 through the tube 225 passing through the second opening 220 in order to reduce the oxygen concentration in the tank 200.

[0077] After introducing carbon dioxide gas into the tank 200, the oxygen concentration in the sealed tank 200 decreased to 9% by volume. After being submerged in hydrogen peroxide for 12 hours, the oxygen concentration in the sealed tank 200 (as measured by the oxygen sensor 215 in the sealed tank 200) increased to 20.1%. These results demonstrate the feasibility of using porous superhydrophobic materials in the artificial gill garment 100.

[0078] Further testing was performed in a seawater environment, where the environmental conditions were harder to control than in the lab-based tests (i.e., the lab-based tests were performed in a well-ventilated room with well-aerated (carbonated) water). The same experimental setup as shown in FIG. 5 was used, except that instead of hydrogen peroxide, the sealed tank 200 was submerged in seawater. The tank 200 was secured to a nearby rock or rope to ensure that the porous superhydrophobic membrane 210 remained completely submerged in seawater.

[0079] The oxygen concentration in the sealed tank 200 was reduced to 14.22% by volume by leaving the porous superhydrophobic membrane 210 submerged in seawater for approximately one hour, where the oxygen concentration in the tank 200 was reduced by drawing in air from within the tank 200 via tube 225.

[0080] FIG. 6 shows the results obtained from the above-mentioned seawater environment test. FIG. 6 shows the oxygen concentration in the sealed tank 200 plotted as a function of time. The trend of the plot shows that the oxygen concentration in the tank 200 increases over time, confirming the results obtained from the laboratory-based test. Clearly, the porous superhydrophobic membrane 210 allows the exchange of oxygen and carbon dioxide gases between the sealed tank 200 and the environment surrounding the sealed tank 200.

[0081] The surface area of ​​the tested porous superhydrophobic membrane 210 was 6 cm 2 The change in oxygen concentration in tank 200 during the seawater test was approximately 0.5% per hour. Tank 200 has a capacity of 565 mL, and oxygen was released through porous superhydrophobic membrane 210 at a rate of 0.075 mL / (hr·cm 2 ) The average human oxygen consumption rate is 14,400 mL per hour.

[0082] From the above, the surface area required to support human breathing is approximately 19.2 m 2It can be calculated that the surface area of ​​a garment made from such a film can be increased by utilizing a surface pattern or surface shape or configuration as described above. Some garments may not have the required amount of surface area. For example, an artificial gill garment may only cover the respiratory features of the wearer's torso and face, but cannot utilize the additional surface area available if the artificial gill garment also covers one or more limbs of the user. In such cases, the artificial gill garment may be used in combination with a rebreather (as described above) or oxygen tank to provide optimal breathing conditions for the wearer.

[0083] FIG. 7 shows optical microscopy images of the surface of a 3D printed part produced by 3D printing composite fibers of TPU and PVOH. FIG. 7A shows an optical microscopy image at a lower magnification than that used for the optical microscopy image shown in FIG. 7B. The scale bar is shown in the lower right corner of each microscopy image. These images were captured after cleaning the 3D printed part with a mixture of distilled water and ethanol and before coating the part with a hydrophobic coating. The image in FIG. 7A shows good adhesion of adjacent layers to achieve sealing of the 3D printed part. Even after cooling, no breakage or delamination between adjacent layers was observed in the 3D printed garment. This indicates that the layers are well bonded. In this way, water is prevented from penetrating through poorly bonded layers, and the 3D printed garment formed as described above can encapsulate the space between the artificial gill garment and the wearer.

[0084] FIG. 8 shows a plot of oxygen concentration in a closed tank as a function of time. The experimental setup used to obtain the results shown in FIG. 8 was the same as that described with respect to FIG. 5 and FIG. 6, except that the porous superhydrophobic membrane was a membrane of TPU with 50% porosity (first fabricated from an initial TPU:PVOH composition of 50:50 by weight). The thickness of the TPU membrane was 400 micrometers. From FIG. 8, it can be seen that a gas-permeable waterproof membrane comprising a porous TPU with a fluoroalkyl-based polymeric hydrophobic coating is suitable for use as a material for an artificial gill garment.

[0085] From reading the present disclosure, other variations and modifications will be apparent to persons skilled in the art, and may involve equivalent and other features which are already known in the field of gas-permeable waterproof membranes and which may be used instead of or in addition to features already described herein.

[0086] The appended claims are directed to particular combinations of features, but it is to be understood that the scope of the present disclosure also includes any novel feature, any novel combination of features explicitly or implicitly disclosed herein, or any generalization thereof, whether or not it relates to the same invention as currently described in any claim, and whether or not it alleviates any or all of the same technical problems as the present invention.

[0087] Also, features that are described in the context of separate embodiments may also be provided in combination in a single embodiment. Conversely, various features that are, for brevity, described in the context of a single embodiment may also be provided separately or in any suitable subcombination. Applicants hereby notify that new claims may be formulated to such features or combinations of such features during prosecution of this application or any further application derived therefrom.

[0088] For the sake of completeness, it is stated that the term "comprising" does not exclude other elements or steps, and that the terms "a" or "an" do not exclude a plurality, and that a single processor or other unit may fulfill the functions of several means recited in the claims, and that any reference signs in the claims shall not be interpreted as limiting the scope of the claims.

Claims

1. 1. An artificial gill garment for providing oxygen to a wearer in an aquatic environment, comprising: a membrane configured to permit the permeation of air through the membrane and prevent the permeation of water through the membrane; the membrane is configured to provide an air reservoir; The membrane is flexible and configured to cover some or all of the wearer's torso. Artificial gill covering.

2. The artificial gill covering according to claim 1, (i) the membrane is configured to provide an air reservoir directly between the membrane and the wearer; or (ii) the membrane is configured to provide an air reservoir between a plurality of surfaces of the membrane; Artificial gill covering.

3. The artificial gill covering according to claim 1 or 2, the membrane is in fluid communication with the air reservoir and includes a mask portion configured to cover at least a facial respiratory function of the wearer. Artificial gill covering.

4. The artificial gill covering according to any one of claims 1 to 3, The membrane is or comprises a porous hydrophobic or superhydrophobic material. Artificial gill covering.

5. The artificial gill covering according to claim 4, The porous hydrophobic material comprises a hydrophobic coating. Artificial gill covering.

6. The artificial gill garment according to any one of claims 1 to 5, The membrane or the outer surface of the membrane includes a surface pattern and / or a surface configuration to increase the surface area of ​​the outer surface. Artificial gill covering.

7. The artificial gill garment according to any one of claims 1 to 6, The artificial gill garment includes a rebreather configured to extract carbon dioxide from the wearer's breath exhaled into the air reservoir and to allow rebreathing of unused oxygen in the wearer's breath. Artificial gill covering.

8. The artificial gill covering according to any one of claims 1 to 7, The artificial gill garment includes an oxygen tank configured to store oxygen and supply oxygen to the air reservoir. Artificial gill covering.

9. A method for producing the artificial gill garment according to any one of claims 1 to 8, comprising: The artificial gill garment is cast or three-dimensionally printed into the desired shape, the printed garment being air permeable and water impermeable; method.

10. 10. The method of claim 9, forming one or more air permeable and water impermeable regions in the printed garment; method.

11. 11. The method according to claim 9 or 10, The three-dimensional printing includes three-dimensionally printing fibers into a desired shape; The fibers include composite fibers of a hydrophobic material and a hydrophilic material, The method further comprises washing the printed garment with water to remove the hydrophilic material from the printed garment. method.

12. 12. The method of claim 11, the hydrophobic material is or comprises a hydrophobic elastomeric polymer; The hydrophilic material is or comprises hydrophilic particles. method.

13. 13. The method of claim 12, the hydrophobic elastomeric polymer comprises polyurethane; The hydrophilic particles include polyvinyl alcohol, The weight ratio of the polyurethane to the polyvinyl alcohol in the composite fiber is 20:80 to 80:

20. method.

14. The method according to any one of claims 9 to 13, further comprising coating the printed garment with a hydrophobic or superhydrophobic coating. method.

15. The artificial gill covering according to any one of claims 1 to 8, The gas-permeable waterproof membrane is formed from a precursor composition comprising a mixture of hydrophobic and hydrophilic materials. Artificial gill covering.

16. The artificial gill covering according to claim 15, the hydrophobic material is or comprises a hydrophobic elastomeric polymer; The hydrophilic material is or comprises hydrophilic particles. Artificial gill covering.

17. The artificial gill covering according to claim 16, the hydrophobic elastomeric polymer comprises a thermoplastic polyurethane; The hydrophilic particles include polyvinyl alcohol, The weight ratio of thermoplastic polyurethane to polyvinyl alcohol in the mixture is 20:80 to 80:20; Artificial gill covering.

18. The method according to any one of claims 9 to 14, Producing a mixture of hydrophobic and hydrophilic materials; forming a membrane from said mixture of hydrophobic and hydrophilic materials; washing the membrane with water to remove the hydrophilic material from the membrane, thereby forming pores in the membrane, thereby producing a gas-permeable waterproof membrane. method.

19. 20. The method of claim 18, further comprising treating the surface of the membrane to impart hydrophobic properties. method.

20. 20. The method of claim 18 or 19, the hydrophobic material is or comprises a hydrophobic elastomeric polymer; The hydrophilic material is or comprises hydrophilic particles. method.

21. 21. The method of claim 20, the hydrophobic elastomeric polymer comprises polyurethane; The hydrophilic particles include polyvinyl alcohol, The weight ratio of polyurethane to polyvinyl alcohol in the mixture is from 20:80 to 80:20; method.

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