Electric Eel inspired Energy Generation to Enable Underwater Artificial Gills
Abstract
Naval-based aquanaut missions are largely limited by a divers need for oxygen. Therefore, it is not surprising, that divers have long been interested in developing gill-like technologies, which are capable of supplying a diver with oxygen derived from seawater. This is possible through an electrolysis-based device; however, state of the art energy storage mediums (batteries) areineffective. Batteries are limited in this application because they are exhaustible, expensive, reliant on rare-earth minerals, and heavy. Therefore, to overcome this technical challenge, this proposed work aims to utilize a bio-inspired approach to generate energy through the controlled mixing of seawater.Reverse electrodialysis is a technology capable of converting mixing energy into electricity, and thus could be used to drive an electrolysis system. However, the chief limitation with current state of the art reverse electrodialysis systems is the operational limiting current density. To meet oxygen demands required for navy divers, a reverse electrodialysis system needs to be able to sustain ion currents that meet 1 A/cm2, while most systems only operate at 10 mA/cm2. This currentdensity limitation is linked to inefficient ion transport processes within ion exchange membranes. Thus, the main goal of this work is to begin to identify what structural properties (interface and bulk) generate entropy within a membrane. Thrust one will elucidate the impact of interfacial structure, through advance surface characterization. A fundamental outcome of this thrust is toexplain the role interface structure plays in the resulting ion absorption energy landscape. Thrust two will use advanced tomography based characterization and continuum modeling to probe the impact of of bulk membrane structure. The outcome of this thrust is to define what structures promote unwanted salt and water mixing. Finally, thrust 3 will explore the impact seawater constituents play in altering the membrane structure. The outcome of this thrust is to map thedynamic structural changes that may arise in a seawater-based environment. This work will result in a comprehensive database of membrane structure-property relationships, which can then be used to engineer, synthesize, and manufactured near-perfect ion exchange membranes. Long-term thismay enable to generation of an artificial gill, whereby a naval diver is able to produce an inexhaustible supply of oxygen from only seawater.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jun 17, 2020
- Source ID
- N000142012559
Entities
People
- Marta C. Hatzell
Organizations
- Georgia Tech Research Corporation
- Office of Naval Research
- United States Navy