The mola, or sunfish, is a large, flat, tropical fish that gets its name from its regular rising to the surface to bask in the sun. Scientists aren't sure if the sunlight helps them digest food or whether this surface floating is just an invitation to birds to come peck and clean parasites from its skin, but Aeroenvironment has created an autonomous, underwater solar-powered robot inspired by this behavior.
As you can see in the video above, the Mola robot is powered along by a large flat solar panel and mechanical fins that propel in the water. It has a solar tail that extends when extra power is needed. There is no onboard power storage for the robot; it's directly powered by the sun.
The Mola is designed to not just swim at the surface but to descend as far as it can while still gathering sunlight. While just a proof of concept right now, the robot features onboard physical, chemical and biological sensors and a data recording device that would allow it to carry out scientific surveys and ocean monitoring missions. Being fully solar-powered means the Mola could gather data without limits to how long or how far it could be out to sea.
While only five percent of solar energy makes it through the surface of the water, end even less makes it any deeper, the Mola gathers enough to swim at a constant speed of 4 KPH and power the sensors.