Modern submarines rely on sonar and vision for navigation, however these systems have limitations. Blind spots and dark, murky water can make them useless. It is because of this that Douglas Jones of the University of Illinois at Urbana-Champaign and Chang Liu of Northwestern University have developed sensors based on the lateral lines of fish.
Fish lateral lines are clusters of hair cells called neuromasts that run along the length of a fish. These hairs allow fish to detect changes in water pressure and are what allow them to swim in closely grouped schools without running into each other and swim through darkened waters blindly.
Jones and Liu have developed artificial lateral lines using silicon fibers and have tested them attached to a metal tube submerged in water. They found that the fibers were able to detect movement in the surrounding water and they were then able to analyze the data and calculate the distance to various objects.
By placing these sensors on submarines, the hope is to make nautical travel more safe and efficient in the areas that current sonar and vision systems are lacking. A true example of biomimicry, these artifical lateral lines would indeed be a societal win by improving upon a modern, somewhat inefficient system by incorporating mechanics of nature.
Scientists create sensors for subs based on fish anatomy: http://www.gizmag.com/researchers-create-lateral-line-sensors/14141/
Giving Robots a sixth sense to see in the murky depths: http://www.gizmag.com/snookie-underwater-robot-lateral-line/14657/
Marks, Paul. “Fishy Sensors Could Keep Submersibles Out Of Trouble.” New Scientist 205.2745 (2010): 19. Academic Search Premier. Web. 14 Nov. 2013.
Distant touch hydrodynamic imaging with an artificial lateral line: http://www.pnas.org.proxy2.library.illinois.edu/content/103/50/18891.full#cited-by