Microbial Fuel Cells (MFCs) are emerging as a viable power source in the marine environment. MFCs function through the transport of electrons from bacterial populations as a result of naturally occurring metabolic processes. The bacteria metabolize organic material in sediment on ocean floors, estuaries, and other similar environments. MFCs offer great potential as a continuous long term power source for low-power applications because they harness electricity from naturally occurring processes in the marine sediment, which naturally renews its fuel supply.
Carbon cloth is one type of anode that is used for MFCs. However, use of carbon cloth currently requires divers to manually bury the cloth in sediment, which is costly and time-consuming. A need exists for a device that can effectively and efficiently bury fabric cloth, such as carbon cloth, in marine sediment without the use of divers.
It should be noted that sled 20 may have various configurations, as long as it contains a first end 22, second end 24, and partially-open bottom surface 26 proximate to second end 24. As such, one having ordinary skill in the art will recognize that various beams, cross-members, or other components may be incorporated into sled 20 to increase structural integrity or otherwise improve the sled design, in addition to or in lieu of, those shown in
Fabric deployer 30 comprises a tubular structure 32 having a slot 34 therein extending lengthwise along tubular structure 32 facing away from first end 22. A sediment disruption device 40 is located opposite fabric deployer 30 and faces first end 22. In some embodiments, fabric deployer 30 includes sediment disruption device 40. In such embodiments, fabric deployer 30 and sediment disruption device 40 are formed from one contiguous structure, as shown in
A fabric cloth 50 (see
In some embodiments, fabric cloth 50 is a conductive cloth, such as carbon cloth. Such a conductive fabric cloth may be useful for many applications, including use as an anode for microbial fuel cells (MFCs). The size of fabric cloth 50 may vary depending on the desired output requirement of the MFC. As an example, fabric cloth 50 may have the dimension of one meter by one meter. System 10 may further include a cathode 90 connected by an electrical connection to electronics package 70 (see
Referring to
Electronics package 70 is also held into place within sled 20 by grooves 29 formed within sled 20. As discussed in more detail with respect to
In some embodiments, release mechanism 60 is a magnet that protrudes from sled 20, as shown in
In other embodiments, release mechanism 60 may be other types of mechanical release mechanisms recognized by one having ordinary skill in the art, such as Velcro®. In such an embodiment, the size of the contact area between the Velcro® release mechanism 60 and the corresponding Velcro® attachment on electronics package 70 may vary depending on factors such as the weight of electronics package 70 and the towing speed of sled 20, to ensure proper releasing and deployment of electronics package 70.
Referring to
As shown in
As system 10 is towed across the surface of sediment 14, sediment disruption device 40 will cause sediment to pile up above sediment disruption device 40 and to flow upward through partially open bottom surface 26 of sled 20 until it contacts electronics unit 72 and plate 74. Upon contact, the sediment will cause a force upon electronics unit 72 and plate 74 that is great enough to break the attraction between release mechanism 60 and electronics unit magnet 76, causing electronics package 70 to break free of sled 20, as shown in
As electronics package 70 is connected to fabric cloth 50 by tethers 80, as electronics package 70 gets further away from sled 20, fabric cloth 50 is pulled through slot 34 into the sediment. As fabric cloth 50 is exposed to sediment 14, the sediment flowing upward through partially open bottom surface 26 moves through the back end of sled 20 and falls onto the area where fabric cloth 50 is exposed, thus burying fabric cloth 50 in the sediment. The final result is a buried fabric cloth as shown in
During the burying process, a driver of the boat towing system 10 will experience some resistance as fabric cloth 50 is being buried. After all of fabric cloth 50 has been pulled from fabric deployer 30, the resistance will lessen and the driver can begin to bring system 10 up to the surface of body of water 12. The deployment process may take several minutes. As an example, fabric cloth 50 may be buried 6-8 inches below the surface of the sediment. In many environments, disrupted sediment will settle over time and add, for example, 2-4 inches of sediment to further settle above the anode. Further, the configuration of system 10 shown in
Many modifications and variations of the System for Deploying Fabric Cloth in Marine Sediment are possible in light of the above description. Within the scope of the appended claims, the embodiments of the systems described herein may be practiced otherwise than as specifically described. The scope of the claims is not limited to the implementations and embodiments disclosed herein, but extends to other implementations and embodiments as may be contemplated by those having ordinary skill in the art.
This application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/382,382, filed Sep. 13, 2010, entitled “Diver-Less Deployment Device for Sediment Microbial Fuel Cells,” the content of which is fully incorporated by reference herein.
The System for Deploying Fabric Cloth in Marine Sediment is assigned to the United States Government and is available for licensing for commercial purposes. Licensing and technical inquiries may be directed to the Office of Research and Technical Applications, Space and Naval Warfare Systems Center, Pacific, Code 72120, San Diego, Calif., 92152; voice (619) 553-2778; email ssc_pac_T2@navy.mil. Reference Navy Case No. 100737.
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Tender et al. The first demonstration of a microbial fuel cell as a viable power supply: Powering a meteorological buoy. 2008. J. of Power Sources 179: 571-575. |
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Number | Date | Country | |
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61382382 | Sep 2010 | US |