SPAWAR Multi-Sled

diment, a graphite cathode floating in the water, and an electronics package housing the battery, circuitry and the device. Electrons are released by microbial colonies within the sediment and are transferred to the anode sheet. The electrons then travel through the electronic load to the cathode, and it is the flow of electrons from the anode to cathode that trickle charges the battery powering these devices.    The amount of electrons collected and the power output are directly related to the surface area of the carbon fabric anode. In order for the anode to supply enough power to the devices, the carbon fabric anode must have a large area. Because of the size of the carbon fabric anode, 15 m2, an unmanned deployment sled was developed. The previous sled was designed to be deployed behind a boat and towed behind it. As the sled was dragged along the sediment it would begin to bury itself. The sled will deposit the electronics package above the setup as it is being dragged causing the carbon fabric anodes to be released under the sediment.

Objectives

    The objective for this project was to redesign the sled to be able to deploy two MFC's a set distance apart under the ocean sediment. The previous design of the sled allowed for one carbon fabric anode sheet to be deployed generating roughly 100 mW. By doubling the number of carbon fabric anode sheets, the MFC's would have double the surface area resulting in double the power generation. The secondary objective was to segment the carbon fabric anode sheets rather than deploying one complete anode sheet. The team was to design a way to load the segmented anode sheets along with the multiple wires attached to each segment into the stainless steel tube housing.

Final Design of the Sled

    The final design of the sled was very similar to the original sled. Since the original sled performed so well, drastic changes to the design of the new sled were avoided in order ensure the newly designed sled would perform similarly to the original sled. With that in mind, there were necessary changes to be made that would improve the performance of the sled, as well as make loading of the anode sheets quick and easy.