Sound controls

MIT has developed a sound-powered underwater camera

Researchers at the Massachusetts Institute of Technology (MIT) have developed a wireless, battery-less underwater camera that could be used to monitor the effects of climate change, explore the unknown and track pollution levels.

The ocean makes up about 70% of the Earth’s surface and yet we seem to know more about the Moon and Mars than we do about the ocean floor. In fact, 95% of the ocean still remains unexplored, due to the incredible depths it reaches and the advanced technology needed to study it.

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At the deepest point in the ocean, known as the Mariana Trench, you could put all of Mount Everest under water and still have a mile of sea above – giving you an idea of ​​the actual extent of the ocean.

The camera is capable of taking color photos even in dark underwater environments and images can be transmitted wirelessly through water, meaning exploration missions could last for weeks and be able to cover more ground than ever before.

One of the challenges of deep sea exploration is cost – it’s expensive to power underwater cameras for long periods of time because you need some kind of vessel to charge the batteries. This new camera from MIT is powered by the sound of ocean waves and converts it into electrical energy to power imaging and communications equipment.

“One of the most exciting applications of this camera for me personally is in the context of climate monitoring,” said Fadel Adib, (opens in a new tab) associate professor in the Department of Electrical Engineering and Computer Science and director of the Signal Kinetics group at MIT.

“We are building climate models, but we lack data for more than 95% of the ocean. This technology could help us build more accurate climate models and better understand how climate change is affecting the underwater world.”

Associate Professor Fadel Adib (left) and research assistant Waleed Akbar (right) with the underwater camera
(Image credit: Adam Glanzman)

In order to create a battery-free camera, scientists had to find a way for the camera to use its environment to generate electricity. They came up with the idea of ​​using sound and equipped the device with piezoelectric materials that produce an electrical signal when a mechanical force is applied. When sound waves generated by passing ships or marine life are detected, they strike the transducers, causing them to vibrate and converting mechanical energy into electrical energy – smart!

Not only can the energy generated by the sound be used to control the device and capture photos, but it is also used to transmit data. By converting the images into bits (1s and 2s), they can be sent one by one to a receiver. “The receiver transmits the sound waves through the water to the camera, which acts like a mirror to reflect those waves,” says MIT.

“The camera reflects a wave back to the receiver or changes its mirror to an absorber so that it is not reflected.” The process is known as underwater backscatter and has been successfully tested in several underwater environments.

With a working prototype developed, researchers are now looking at ways to further improve it by being able to record video, stream images in real time, and increase receiver range. With sea levels rising and warming at a frightening rate, there has never been a more important time to monitor the effects of climate change. Hopefully devices like this will become available to more and more people, businesses and charities dedicated to preserving our seas, oceans and the wildlife that call them home.