Patent Publication Number: US-2020303756-A1

Title: Deployment Device and Methods for an Oxygen-Barrier-Based Surface Benthic Microbial Fuel Cell

Description:
FEDERALLY-SPONSORED RESEARCH AND DEVELOPMENT 
     The United States Government has ownership rights in the subject matter of this invention. Licensing inquiries may be directed to Office of Research and Technical Applications, Space and Naval Warfare Systems Center, Pacific, Code 72120, San Diego, Calif., 92152; telephone (619) 553-5118; email: ssc_pac_t2@navy.mil. Reference Navy Case No. 103,686. 
    
    
     BACKGROUND OF THE INVENTION 
     Technical Field 
     The present disclosure relates to technologies for continuous power generation. Particularly, the present disclosure relates to technologies for continuous power generation in a marine, freshwater or brackish environment. 
     Description of the Related Art 
     In the related art, for benthic microbial fuel cell (BMFC) anodes, operation under anaerobic conditions is challenging as the functionality thereof is adversely affected by the presence of oxygen, thereby adversely affecting the microbiology and chemistry that should, otherwise, be driving power production. Related art installation methods of these large-scale anodes of BMFCs under ocean floor sediment is difficult, time consuming, and almost impossible in very deep water. Thus, the related art deployment methods involve challenges in attempting to deploy large surface anode systems, such as limited diver-assisted deployments, wherein the weight and unwieldy nature of a surface anode render the effort difficult and cumbersome. Additionally, small scale related art BMFC systems are limited by their active surface area and will produce very low power. Therefore, a need exists for systems and methods that facilitate deployment of BMFC systems for providing a renewable energy in any marine environment. 
     SUMMARY OF THE INVENTION 
     The present disclosure generally involves a deployment device, comprising: a frame; and a deployment mechanism operably coupled with the frame and configured to perform at least one of deploy and retract a plurality of surface benthic microbial fuel cell systems in at least one manner of manually, autonomously, and semi-autonomously. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above, and other, aspects and features of several embodiments of the present disclosure will be more apparent from the following Detailed Description of the Invention as presented in conjunction with the following several figures of the Drawings. 
         FIG. 1  is a diagram illustrating a perspective view of a surface benthic microbial fuel cell (SBMFC) system, comprising an oxygen-barrier layer and a BMFC system, the SBMFC system in an unfurled state, e.g., ready for furling into a transportable state, in accordance with an embodiment of the present disclosure. 
         FIG. 2  is a diagram illustrating a perspective view of an SBMFC system, comprising an oxygen-barrier layer and a BMFC system, the SBMFC system in a rolled or furled state, e.g., ready for transport and prior to deployment, in accordance with an embodiment of the present disclosure. 
         FIG. 3  is a diagram illustrating a perspective view of a deployment device accommodating a plurality of SBMFC systems, the plurality of SBMFC systems being ready to deploy, in accordance with an embodiment of the present disclosure. 
         FIG. 4  is a diagram illustrating a perspective view of a deployment device, as shown in  FIG. 3 , comprising a deployment mechanism, the plurality of SBMFC systems being fully deployed, in accordance with an embodiment of the present disclosure. 
         FIG. 5  is a diagram illustrating a perspective view of a deployment device, as shown in  FIG. 3 , comprising a deployment mechanism, as shown in  FIG. 4 , in accordance with an embodiment of the present disclosure. 
         FIG. 6  is a flow diagram illustrating a method of fabricating an SBMFC system, in accordance with an embodiment of the present disclosure. 
         FIG. 7  is a flow diagram illustrating a method of fabricating a deployment device for deploying a plurality of SBMFC systems, in accordance with an embodiment of the present disclosure. 
         FIG. 8  is a flow diagram illustrating a method of deploying a plurality of SBMFC systems by way of a deployment device, in accordance with an embodiment of the present disclosure. 
         FIG. 9  is a diagram of a SBMFC system in a deployed configuration having a flat hose to be pressurized to inflate for deployment. 
         FIGS. 10A and 10B  show a diagram of a SBMFC system in a deployed configuration and in a rolled configuration, respectively. 
         FIG. 11  shows a diagram of a SBMFC system wherein the deployment device may further comprise a retraction mechanism/winch. 
     
    
    
     Corresponding reference numerals or characters indicate corresponding components throughout the several figures of the Drawings. Elements in the several figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be emphasized relative to other elements for facilitating understanding of the various presently disclosed embodiments. Also, common, but well-understood, elements that are useful or necessary in commercially feasible embodiments are often not depicted in order to facilitate a less obstructed view of these various embodiments of the present disclosure. 
     DETAILED DESCRIPTION OF THE INVENTION 
     In order to address many of the related art challenges, the present disclosure generally involves a deployment device having a deployment mechanism, a method of fabricating the deployment device, and a method of operating the deployment device for deploying an oxygen-barrier-based SBMFC. The present disclosure also generally involves an SBMFC system, comprising a BMFC, that is configured to facilitate disposal of a plurality of anodes on a sediment surface, e.g., without requiring burial under the sediment surface, wherein the plurality of anodes is configured to operate under anaerobic conditions. The systems, devices, and methods of the present disclosure are implementable in any aquatic environment, including, but not limited to, marine environments, such as ocean water and sea water, fresh water, and a brackish environments. 
     In embodiments of the present disclosure, the deployment device, comprising the deployment mechanism, and corresponding methods are implemented for use with an SBMFC comprising an oxygen-barrier layer disposed between the anode of a BMFC for maintaining an anaerobic condition and a surrounding water column, the surrounding water column being inherently aerobic. The oxygen-barrier layer maintains the anode under an anaerobic condition without requiring burial. By example only, the oxygen-barrier layer comprises a material which separates the anode from the water column, rather than relying on marine sediment itself to do so as in the related art. This oxygen-barrier layer allows the anodes to operate effectively while disposed on the sediment surface, rather than in the sediment, e.g., without burial, or by eliminating the burial requirement for the plurality of anodes. 
     While this SBMFC system of the present disclosure has a configuration that is believed to be an advancement in BMFC technology, deployment of the SBMFC system is also critical, e.g., automatic, semi-automatic, and/or other mechanized deployment on a large scale, to obtain a usable power level. To avoid the risk and costs associated with related art diver deployments, the subject matter of the present disclosure involves a deployment device, comprising a deployment mechanism, and corresponding methods for a large-scale deployment of a plurality of SBMFC systems. This deployment device involves features for facilitating assembly, transport, loading deployment, and even retraction of large SBMFC systems which do not require the burial of the BMFC anodes. 
     Referring to  FIG. 1 , this diagram illustrates, in a perspective view, an SBMFC system S, comprising: an oxygen-barrier layer  10 ; and a BMFC system  20 , having a plurality of anodes A, such as “surface” anodes, e.g., anodes disposable on the sediment surface, disposed in relation to, e.g., on, the oxygen-barrier layer  10 , the SBMFC system S in an unfurled state, e.g., ready for furling into a transportable state, in accordance with an embodiment of the present disclosure. The SBMFC system S comprises a power output that is scalable as a function of the anode&#39;s area. Although the anode A, in conjunction with the oxygen-barrier layer  10 , operates without burial thereof, to obtain a usable amount of power, a large-scale SBMFC system S is automatically deployed by a deployment device  100  ( FIG. 3 ) of the present disclosure. 
     Still referring to  FIG. 1 , the SBMFC system S is configured to roll or furl into, and to unroll or unfurl from, the deployment device  100 . The SBMFC system S is further configured to unroll or unfurl, e.g., automatically, from the deployment device  100  upon contacting the sediment surface under the marine environment, e.g., the ocean floor, whereby the surface anodes unroll or unfurl. In this manner, a plurality of the SBMFC systems S, carrying a large SBMFC surface area, e.g., a total anode surface in a range of approximately 25 ft 2  to approximately 100 ft 2 , are easily and compactly loadable onto a vessel for automatic deployment. The SBMFC system S further comprises a circuit  30  configured to electrically couple the plurality of anodes A. 
     Still referring to  FIG. 1 , the SBMFC system S is operable by way of a large number of anodes A, e.g., in a range of approximately 4 anodes to approximately 16 anodes, disposed in relation to the oxygen-barrier layer  10 , e.g., on the oxygen-barrier layer  10 . By example only, the oxygen-barrier layer  10  comprises a rubber mat, such as an impermeable ethylene propylene diene monomer (EPDM) rubber mat and any other oxygen-impermeable material layer. The plurality of anodes A are electrically coupled together and are, thus, configured to increase overall power output of the SBMFC system S. In addition, by using a plurality of small anodes, wherein the plurality of anodes A comprises a large number of anodes, such as in a range of approximately 4 anodes to approximately 16 anodes, e.g., in a preferred range of approximately 4 anodes to approximately 10 anodes, and wherein the plurality of anodes A are electrically isolated, and whereby failure of the SBMFC system S is preventable. The SBMFC system S overcomes many challenges in the related art, such as the failure of one anode A causing failure or remaining anodes A. 
     Referring to  FIG. 2 , this diagram illustrates, in a perspective view, an SBMFC system S, comprising: an oxygen-barrier layer  10 ; and a BMFC system  20 , having a plurality of anodes A, disposed in relation to, e.g., on, the oxygen-barrier layer  10 , the SBMFC system S in a rolled or furled state, e.g., ready for transport and prior to deployment, in accordance with an embodiment of the present disclosure. Once the plurality of anodes A is disposed in relation to, e.g., on, the oxygen-barrier layer  10  and is electrically coupled with the circuit (not shown), the SBMFC system S can be rolled or furled. Rolling or furling the SBMFC system S optimizes its size and reduces its complexity, thereby facilitating its transport and loading in relation to the deployment device  100  as well as in relation to the automatic or semi-automatic deployment thereof. 
     Referring to  FIG. 3 , this diagram illustrates, in a perspective, a deployment device  100  for deploying a plurality of SBMFC systems S, the plurality of SBMFC systems S being ready to deploy, in accordance with an embodiment of the present disclosure. The deployment device  100  comprises a frame F. By example only, once a plurality of SBMFC systems S, each SBMFC system S comprising a BMFC system  20  having a plurality of anodes A, is rolled or furled, the plurality of SBMFC systems S are readily disposable in relation to the deployment device  100 . In accordance with an embodiment of the present disclosure, the deployment device  100  accommodates up to approximately four rolled or furled SBMFC systems S, wherein each SBMFC systems S comprises a length in a range of up to approximately thirty meters (30 m). Once the plurality of SBMFC systems S are rolled and loaded in relation to the deployment device  100 , the plurality of SBMFC systems S are easily transportable to a specific location and dropped or lowered into a marine environment. 
     Referring to  FIG. 4 , this diagram illustrates, in a perspective, a deployment device  100 , as shown in  FIG. 3 , comprising a deployment mechanism D, the plurality of SBMFC systems S being fully deployed, in accordance with an embodiment of the present disclosure. The SBMFC systems S further comprises a corresponding plurality of cathodes C. The plurality of SBMFC systems S, fully deployed, has an overall power output in a range of approximately five-hundred milliwatts (500 mW) to approximately eight-hundred milliwatts (800 mW). However, the overall power output may vary as a function of the materials used in fabricating the plurality of SBMFC systems S; and any such variations in overall power output are also encompassed by the present disclosure. The overall power output of the plurality of SBMFC systems S far exceeds that of any one SBMFC systems S. Once the deployment device  100  reaches or “hits” the marine sediment surface, e.g., an ocean floor, the plurality of SBMFC systems S unrolls or unfurls, thereby commencing sustainable power production. 
     Still referring to  FIG. 4 , the cathodes C are indicated by vertical arrows and extend from an upper surface of the oxygen-barrier layer  10  (visible in  FIG. 2 ), e.g., comprising at least one of a rubber material mat and any other impermeable material. Openings P facilitate pass-through for electronic wiring and coupling the electrical wiring with at least the cathodes C. In the SBMFC systems S, the plurality of anodes A (visible in  FIG. 1 ) and the corresponding plurality of cathodes C are coupled together via an electronics circuit (visible in  FIGS. 9-11 ). In an embodiment, an anode wiring (not shown) is disposed through the opening P to an upper surface of the oxygen-barrier layer  10  and coupled with the electronic circuit, wherein the electronic circuit is disposed at, or otherwise in relation to, the opening P for facilitating energy harvesting. In another embodiment, a cathode wiring (not shown) may pass through an opening P and to a bottom surface of the oxygen-barrier layer  10 , wherein the electronic circuit is disposed thereunder. In yet another embodiment, the anode wiring and the cathode wiring are coupled with a main electronics package (visible in  FIGS. 9-11 ) disposed in relation to at least one of the oxygen-barrier layer  10  and the frame F, wherein the anode wiring and the cathode wiring are disposable therealong. The deployment mechanism D comprises a buoyant structure, such as a buoy, configured to remotely and/or automatically trigger release and/or retraction of a plurality of systems S. The deployment mechanism D is farther configured to perform at least one of: receive, store, and transmit telemetry data; and indicate position for retrieval of the plurality of systems S. 
     Referring to  FIG. 5 , this diagram illustrates, in a perspective, a deployment device  100 , as shown in  FIG. 3 , comprising a deployment mechanism D, as shown in  FIG. 4 , the plurality of SBMFC systems S fully deployed, in accordance with an embodiment of the present disclosure. The deployment device  100  comprises: a frame F configured to accommodate a plurality of SBMFC systems S; and a deployment mechanism D operably coupled with the frame F. The frame F comprises a plurality of horizontal members H, vertical members V, and curved members  50 , arranged and coupled together in any configuration that accommodates the plurality of SBMFC systems S. 
     Referring back to  FIGS. 3-5 , the deployment device  100  is configured to deploy and bury the plurality of SBMFC systems S, in accordance with an alternative embodiment of the present disclosure. Divers may manually dispose the deployment device  100  in a marine environment and manually deploy the plurality of SBMFC systems S therefrom, in accordance with yet another alternative embodiment of the present disclosure. A remotely operated vehicle (ROV) may robotically dispose the deployment device  100  in a marine environment and robotically deploy the plurality of SBMFC systems S therefrom, in accordance with yet a further alternative embodiment of the present disclosure. However, these alternative embodiments may involve further considerations, such as deployment location, and deployment depth, logistics, cost, and risk. 
     Referring to  FIG. 6 , this flow diagram illustrates a method M 1  of fabricating an SBMFC system S, in accordance with an embodiment of the present disclosure. The method M 1  comprises: providing an oxygen-barrier layer  10 , as indicated by block  601 ; providing a BMFC system  20 , as indicated by block  602 , providing the BMFC system  20  comprising providing a plurality of anodes A, as indicated by block  603 ; and disposing the BMFC system  20  in relation to the oxygen-barrier layer  10 , as indicated by block  604 . The method M 1  further comprises: providing circuitry for electrically coupling together the plurality of anodes, as indicated by block  605 ; and electrically coupling the plurality of anodes with the circuitry, as indicated by block  606 . The method M 1  further comprises: rolling the SBMFC system S, as indicated by block  607 , thereby readying the system S for transport and disposal in relation to a deployment device  100  ( FIG. 3 ). In the method M 1 , providing the BMFC system  20 , as indicated by block  602 , further comprises providing a corresponding plurality of cathodes C. 
     Referring to  FIG. 7 , this flow diagram illustrates a method M 2  of fabricating a deployment device  100  for deploying a plurality of SBMFC systems S, in accordance with an embodiment of the present disclosure. The method M 2  comprises: providing a frame F configured to accommodate a plurality of SBMFC systems S, as indicated by block  701 ; and providing a deployment mechanism D operably coupled with the frame F, as indicated by block  702 . The method M 2  further comprises: providing a retraction mechanism. In the method M 2 , providing the deployment mechanism D, as indicated by block  702 , further comprises providing the deployment mechanism D as operable with the plurality of SBMFC systems S. 
     Still referring to  FIG. 7 , in an embodiment of the method M 2 , providing the deployment mechanism D comprises: providing an underwater modem, providing a battery, providing a high-pressure pump, and providing at least one hose (not shown), e.g., at least one fabric hose, coupled with each system S along a length portion thereof. Providing the at least one hose comprises configuring the at least one hose to store in a flat disposition for facilitating transport thereof as well as to roll with the system S. Providing the water pump comprises configuring the water pump activate and fill the at least one hose with high-pressure water from the aquatic environment by receiving a signal, e.g., from either the underwater modem or a tethered cord, whereby. the at least one hose becomes turgid and straightens, and whereby unrolling each system S is activated in a controllable manner, e.g., a controllable rate of unfurling. 
     Still referring to  FIG. 7 , in an embodiment of the method M 2 , providing the deployment mechanism D comprises providing a spring device (not shown), such as at least one of: a spring, e.g., a thin spring metal, and any other memory material configured to provide a force required for unrolling or unfurling each system S. If providing the spring device, the system S is rolled with the spring device disposed along a length portion thereof. The system S, when rolled, is stored under compression to prevent unrolling during transit thereof. Providing the deployment mechanism D of this embodiment further comprises providing a release device (not shown), such as at least one of: providing a mechanical switch and providing a burn wire, wherein the release device is activated once the system S is disposed at the sediment surface to achieve deployment thereof. 
     Still referring to  FIG. 7 , in yet another embodiment of the method M 2 , providing the deployment device  100  further comprise providing a retraction mechanism (not shown). Providing the deployment device  100  comprises configuring the deployment device  100  to perform at least one of: deploy and retract the plurality of SBMFC systems S, autonomously deploy and retract the plurality of SBMFC systems S, and semi-autonomously deploy and retract the plurality of SBMFC systems S. Providing the deployment device  100  further comprises configuring the deployment device  100  as scalable and configurable to accommodate more than four SBMFC systems S, whereby various power requirements for given implementations are achievable. By example only, providing the retraction mechanism comprises providing a winch (not shown) disposed at a base of the frame F for each system S. When activated, e.g., either via an acoustic modem or a timed event, the winch securely spools the systems S to the frame F for retrieval. Providing the buoyant structure, such as a buoy, comprises disposing the buoyant structure at a center of the frame F, whereby the buoyant structure is then be usable for location and retrieval of the device  100  and the systems S. 
     Referring to  FIG. 8 , this flow diagram illustrates a method M 3  of deploying a plurality of SBMFC systems S by way of a deployment device  100 , in accordance with an embodiment of the present disclosure. The method M 3  comprises: providing the deployment device  100 , as indicated by block  801 ; disposing the plurality of SBMFC systems S in relation to the deployment device  100 , as indicated by block  802 ; disposing the deployment device  100 , accommodating the plurality of SBMFC systems S, on a marine floor, as indicated by block  803 ; and  100 , as indicated by block  804 . The method M 3  may further comprise retracting the plurality of SBMFC systems S to the deployment device  100 , as indicated by block  805 . 
     Understood is that many additional changes in the details, materials, steps and arrangement of parts, which have been herein described and illustrated to explain the nature of the invention, may be made by those skilled in the art within the principle and scope of the invention as expressed in the appended claims. 
       FIG. 9  is a diagram of a SBMFC system S in a deployed configuration having a flat hose  900 , to be pressurized to inflate for deployment. In  FIG. 9 , the deployment mechanism D, having waterproof underwater housing, comprises at least one of: an underwater acoustic modem  905 , a controller for data storage  910 , a battery  915 , a high-pressure pump  920 , and at least one hose  925 , such as at least one fabric hose, e.g., a pair of hoses, coupled with each system S along a length portion thereof. The at least one hose is configured to store in a flat disposition for facilitating transport thereof as well as to roll and/or unroll with the system S. By receiving a signal, e.g., from either the underwater modem or a tethered cord, the high-pressure pump  920  activates to fill the at least one hose  925  with high-pressure water from the aquatic environment. By filling the at least one hose  925  with the high-pressure water, the at least one hose  925  becomes turgid and straightens, thereby activating unrolling each system S in a controllable manner, e.g., a controllable rate of unfurling. System S also has a distribution manifold  930 . 
       FIG. 10A  is a diagram of a SBMFC system S in a deployed configuration and  FIG. 10B  is a diagram of a SBMFC system S in a rolled configuration. In  FIGS. 10A and 10B , SBMFC system S has a spring mechanism  1000  to be used for unfurling. Spring mechanism  1000  comprises at least one of: a spring, e.g., a thin spring metal, and any other memory material configured to provide a force required for unrolling or unfurling each system S. System S is rolled with spring mechanism  1000  disposed along a length portion thereof. The system S, when rolled, is stored under compression to prevent unrolling during transit thereof. The deployment mechanism D of this embodiment further comprises a release device  1010  such as at least one of: a mechanical switch and a burn wire, wherein the release device is activated once the system S is disposed at the sediment surface to achieve deployment thereof. 
       FIG. 11  shows a diagram of a SBMFC system S, wherein, the deployment device D may further comprise a retraction mechanism/winch  1100 . Deployment device D is configured to perform at least one of: deploy and retract the plurality of SBMFC systems S, autonomously deploy and retract the plurality of SBMFC systems S, and semi-autonomously deploy and retract the plurality of SBMFC systems S. Deployment device D is further scalable and configurable to accommodate more than four SBMFC systems S, whereby various power requirements for given implementations are achievable. By example only, retraction mechanism/winch  1100  is disposed at a base of the frame F (shown in  FIG. 5 ) for each system S. When activated, e.g., either via an acoustic modem or a timed event, retraction mechanism/winch  1100  securely spools the systems S to the frame F for retrieval. The buoyant structure, such as a buoy, disposed at a center of the frame F is then be usable for location and retrieval of the device  100  and the systems S.