In many ways, we know more about deep space billions of miles away than our deep oceans here on earth. Only 5% of the oceans have been observed, and to remedy this, MIT engineers have built a battery-free underwater camera to push deep sea exploration to the next level. It’s fascinating!
The overall goal is to keep an eye on the environment and flag cases of pollution and climate change damages. The duration the camera can stay underwater without any support is paramount because changing the battery is costly.
Photo description from MIT: “Fadel Adib (left) associate professor in the Department of Electrical Engineering and Computer Science and director of the Signal Kinetics group in the MIT Media Lab, and Research Assistant Waleed Akbar display the battery-free wireless underwater camera that their group developed.”
To work around this, MIT researchers convert the ocean’s ambient noise (sound energy) into electricity enough to capture color photos and transmit them wirelessly without a battery. Such capabilities enable researchers to drop the camera in places where they don’t have to retrieve it regularly, improving the chances of finding new species.
The energy is harvested by piezoelectric materials that convert any force applied to them into electricity. Once enough power has been harvested, it can be released and utilized to capture and transmit photos.
The communications system also benefits from piezoelectric materials using a backscatter networking (PDF link) technique which is many orders of magnitude (thousands of times) more energy-efficient than standard networking technologies. Essentially, instead of emitting energy to transmit a signal, the device reflects surrounding energy (or not) to emit digital 0 and 1 signals.
So far, the camera can transmit 40 meters underwater, which does not qualify as a “deep ocean,” but much work is going into extending this capability. Creating a battery-free underwater camera is a remarkable technical feat. Making it work ever deeper is the next level.