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US-20260125140-A1 - ENERGY EFFICIENT UNDERWATER INFLATABLE ARRAY USING HYDROFOAM AND WATER SWELLING MATERIAL

US20260125140A1US 20260125140 A1US20260125140 A1US 20260125140A1US-20260125140-A1

Abstract

Underwater Deployable Structures (UDSs) capable of achieving inflation via mechanical pumps, moisture-activated expanding foams, water swelling material, or a hybrid of a mechanical pump and water swelling material. Moisture expanding foams begin as polyurethane-based resins of low viscosity, and react in the presence of water to become solid foam. In their final forms, the foams exist as open- or closed-cell, and vary in strength, elasticity, and rigidity. Water swelling material is also disclosed wherein the water swelling material is capable of achieving expansion numerous (e.g., up to about 250) times its initial volume when in contact with water and can shrink back to its initial volume upon dehydration, making the UDSs reusable. A mechanical pump may optionally be used to assist in initial inflation until the water swelling material reaches full expansion.

Inventors

  • Bing Ouyang
  • Tsung-chow SU
  • Yanjun Li
  • Jordan THOMAS

Assignees

  • FLORIDA ATLANTIC UNIVERSITY BOARD OF TRUSTEES

Dates

Publication Date
20260507
Application Date
20241030

Claims (20)

  1. 1 . A method of making a foam object for an underwater deployable structure, the method comprising: depositing a moisture-activated foam substance onto a substrate, the moisture-activated foam substance being expandable in volume from an unexpanded state to an expanded foam; and activating a chemical reaction of the moisture-activated foam substance with moisture to expand the moisture-activated substance in volume to the expanded foam.
  2. 2 . The method of claim 1 , the depositing step including controlling a 3D printer configured to deposit the moisture-activated foam substance onto the substrate.
  3. 3 . The method of claim 2 , further comprising mixing components of the moisture-activated foam substance together in the 3D printer that deposits the moisture-activated foam substance onto the substrate.
  4. 4 . The method of claim 2 , the depositing step including depositing the moisture-activated foam substance into a cavity of the substrate with the 3D printer, wherein the substrate includes a mold having walls that define the cavity, and the expanded foam is defined by the walls, the walls forming a plurality of beams coupled together, the beams being mechanically expandable underwater from an unexpanded configuration to an expanded configuration; the beams having the walls of the cavity with hallowed sections therein defining the cavity, and the expanded foam is flexible and extends into the cavity within the beams and elastically supports the coupling of the beams.
  5. 5 . The method of claim 1 , wherein the chemical reaction is an exothermic chemical reaction that generates thermal energy, and further comprising mixing components of the moisture-activated foam substance together with a mixing device using the thermal energy to mix the components of the moisture-activated foam substance together.
  6. 6 . The method of claim 5 , the underwater deployable structure including anchors attached to the plurality of beams, the anchors being driven by the thermal energy for attachment to an underwater seabed.
  7. 7 . The method of claim 1 , the depositing step including depositing the moisture-activated foam substance into a cavity of the substrate, the cavity being a buoyance container, and the activating step is provided by a deployment mechanism adjacent the buoyance container that allows moisture to access the moisture-activated substance and chemically react with the moisture-activated substance to expand the moisture-activated substance in volume from the unexpanded state to the expanded foam, the underwater deployable structure deployable to a first underwater depth with the moisture-activated substance in the unexpanded state, the expanded foam being lighter than water and configured to raise the underwater deployable structure from the first underwater depth to a second underwater depth shallower than the first underwater depth.
  8. 8 . A method of making an automatic modifiable array of an underwater deployable structure, the method comprising: depositing moisture-activated substance into a permeable sleeve, wherein the moisture-activated substance is capable of expanding in volume from an initial unexpanded state upon contact with water and contracting in volume upon being removed from water; and encasing the permeable sleeve into the array of the underwater deployable structure, wherein the array includes an outer layer having water-tight material and an inner layer having the permeable sleeve, wherein submerging the moisture-activated substance in water causes the moisture-activated substance to expand in volume upon contact with the water and increase a rigidity of the array of the underwater deployable structure.
  9. 9 . The method of claim 8 , wherein the moisture-activated substance is an absorbent polymer water swelling material.
  10. 10 . The method of claim 8 , wherein the moisture-activated substance is held in place by water soluble substrate prior to expansion, and the water-soluble substrate dissolves and the moisture-activated substance expands simultaneously.
  11. 11 . The method of claim 8 , further comprising: coupling a mechanical pump to the outer layer; coupling a pressure relief valve to the outer layer; activating the mechanical pump to inflate the underwater deployable structure array until the underwater deployable structure array has achieved a rigid form via expansion of the moisture-activated substance; and deactivating the mechanical pump once the moisture-activated substance has achieved a predetermined expansion.
  12. 12 . An underwater deployable structure device, comprising: an underwater deployable structure; an array attached to the underwater deployable structure, wherein the array includes a tubular structure including an outer layer with hallowed sections therein each defining a cavity well, the outer layer maintaining the form of the tubular structure; and moisture-activated substance located in at least one of the cavity wells, wherein the moisture-activated substance expands in volume when in contact with moisture.
  13. 13 . The underwater deployable structure device of claim 12 , the tubular structure further includes a permeable sleeve having the outer layer and an inner layer attached to the outer layer and defining a cavity well within.
  14. 14 . The underwater deployable structure device of claim 13 , further comprising a mechanical pump, wherein the mechanical pump is configured to pump water into the cavity wells of the array.
  15. 15 . The underwater deployable structure device of claim 12 , wherein the moisture-activated material includes water swelling material that expands upon contact with water shrinks back to its original volume when dehydrated.
  16. 16 . The underwater deployable structure device of claim 12 , further comprising a pressure relief valve, wherein the pressure relief valve is configured to release trapped gasses from within the array.
  17. 17 . The underwater deployable structure of claim 12 , wherein the outer layer includes watertight material.
  18. 18 . The underwater deployable structure of claim 12 , further comprising at least one anchor configured for attachment to an underwater seabed.
  19. 19 . The underwater deployable structure of claim 12 , wherein the array is a buoyance container attached to the underwater deployable structure, the buoyance container including the moisture-activated substance therein being expandable in volume from an unexpanded state to an expanded state via contact with the moisture.
  20. 20 . The underwater deployable structure of claim 12 , wherein the expanded moisture-activated substance is lighter than water and configured to raise the underwater deployable structure from a first underwater depth to a second underwater depth shallower than the first underwater depth.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a Divisional of U.S. application Ser. No. 17/226,913 filed on Apr. 9, 2021, which is a Continuation-in-Part of PCT Application No. PCT/US/2019/045905 entitled CHEMICAL REACTION ACTIVATED EXPANDING MATERIAL FOR UNDERWATER DEPLOYABLE STRUCTURES which claims the benefit under 35 U.S.C. § 119(e) of Application Ser. No. 62/743,219 filed on Oct. 9, 2018 entitled CHEMICAL REACTION ACTIVATED EXPANDING MATERIAL FOR UNDERWATER DEPLOYABLE STRUCTURES and whose entire disclosures are incorporated by reference herein. STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT This invention(s) was made with government support under contract number N00014-18-1-2469 awarded by the Office of Naval Research, and under contract number 1659468 awarded by the National Science Foundation Research Experiences for Undergraduates. The government has certain rights in the invention(s). FIELD OF DISCLOSURE The disclosure relates to water or moisture activated materials. In particular, the disclosure relates to water or moisture activated materials, for example water activated expanding foams and water swelling material such as absorbent polymers, deployable in underwater structures. BACKGROUND Underwater deployable structure (UDS) has been adopted in many undersea applications including undersea robotics for tasks including Explosive Ordnance Disposal (EOD) and uses including underwater sensor frameworks or supporting structure. The conventional UDS design has been mechanical using an underwater pump to pressurize and inflate support beams to a desirable shape. This allows for a compact initial form compared with the inflated dimension of a corresponding structure. The structure inflation starts with the activation of the pump to create a pressure differential between the surrounding water and water inside the UDS to maintain the rigidity of the beams. The benefits to this approach are its relative simplicity, and small compressed volume. However, the need for an underwater pump creates several major drawbacks. First of all it requires an additional power source to drive the pump not only to inflate the structure but also to maintain the rigidity of the structure through the course of the operation or use of the structure. Secondly, the speed of the inflation is dependent on the pump power. This will be a constraint on the system energy requirement. Furthermore, a powerful pump tends to be bulky and increases the initial stowed volume of the UDS. To help overcome these drawbacks and constraints, the inventors discovered that inflating and supporting UDSs via chemical approaches, such as a chemical reaction may be advantageous in many undersea applications, for example, where an undersea platform has significant size, weight and power (SWaP) constraints such as unmanned underwater vehicles (UUVs) or man-portable remotely operated vehicle (ROVs). The inventors additionally discovered that the use of water swelling material is advantageous in situations where long-term inflation, compact storage, energy conservation, and reusability of the UDS is necessary. Further, the combination of the use of a mechanical pump with the water swelling material approach was found to increase the initial time of expansion and require less energy than a purely mechanical approach once the water swelling material achieved full expansion. SUMMARY The following presents a simplified summary in order to provide a basic understanding of some aspects of one or more embodiments or examples of the present teachings. This summary is not an extensive overview, nor is it intended to identify key or critical elements of the present teachings, nor to delineate the scope of the disclosure. Rather, its primary purpose is merely to present one or more concepts in simplified form as a prelude to the detailed description presented later. Additional goals and advantages will become more evident in the description of the figures, the detailed description of the disclosure, and the claims. An approach advocated in this application includes the water or moisture-activated expanding materials, in particular water-activated expanding foams and water swelling materials, such as water absorbent polymers. Expanding foams are used in the construction industry, for a variety of purposes including sealing, grouting, and structural reinforcement. The inventors determined water- or moisture-activated expanding foams may be applicable because they are designed for use in wet environments and do not deteriorate over a period of days, months or even several years. These foams begin as polyurethane-based resins of low viscosity, and react in the presence of water to become solid foam. For example, the interaction of the molecules in the polymer resin and water molecules initiates a reaction which thickens and solidifies the polymer, and the simultaneous release of carbon dioxide gas creates bubbles which turn the material int