This wireless camera taps into sound waves to reveal deep-sea secrets
MIT scientists presented their prototype of a fascinating underwater camera on Monday. Rather than relying on battery power, this device draws its juice from sound waves that travel across the ocean for its deep-sea imaging escapades. It works even in the darkest of environments.
Then it has the ability to wirelessly transmit all that photo data return through water to be reconstructed on a computer.
This means that if the model can be scaled, it could take humanity a few steps closer to achieving a mammoth goal: mapping every corner of Earth’s oceans.
Although the surface of our beautiful planet is made up of a whopping 70% water (remember, this doesn’t take depth into account), the research team estimates that we’ve only ever observed less than 5% of the sea. And one of the reasons, they say, for such a lack of knowledge is that viable underwater cameras are really hard to build due to battery restrictions.
Simply, a working imager in the sea cannot travel too far from a ship without running out of power. It’s also expensive to make a super long-lasting battery, and it’s not efficient to have to restart an expedition every time the camera at hand needs to be picked up and recharged. So the new sound wave-powered camera has the potential to be a game-changer for deep-sea explorers.
According to an overview of the invention, published in the journal Nature Communications, the device can operate for weeks before someone has to pick it up, allowing it to venture far out to sea in one go. It’s also about 100,000 times more energy efficient than other underwater cameras, the team said.
“One of the most exciting applications for this camera, for me personally, is in the context of climate monitoring,” Fadel Adib, associate professor in MIT’s Department of Electrical Engineering and Computer Science, said in a statement. . “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 the impact of climate change on the underwater world. .”
For example, this camera could easily capture images of ocean pollution, monitor the health of fish raised on aquaculture farms, where commercial fish farming takes place, and perhaps even indicate changes in marine habitats. Right now, the oceans are warming up too quickly due to human-induced climate change, and underwater animals are being driven from their homes, forced to relocate, and sometimes forced to adapt much faster than their body cannot bear it.
As a proof of principle, the research team tested their mechanism to create color images of plastic bottles floating in a New Hampshire pond. They also captured images of an African starfish in such high resolution that you can see the tiny tubercles along its arms. All in all, this seems like a solid path to solving the underwater battery puzzle.
But perhaps even more exciting than the team camera’s long-term implications is the absolutely remarkable way it works.
Turn sound waves into views
Basically, the team explained that this sound wave-powered camera takes advantage of the noise already present under the sea. Passing ships, sea life, tides and other such things create sound. But what exactly is sound?
Sound is not some intangible force. Rather, it is the product of waves traveling through a medium and causing that medium to vibrate on a super (super) minute scale. The medium could be air, water — anything with atoms, really. When air vibrations hit our eardrums, for example, our brain translates the signal into what we think of as sound. This is also why sounds are distorted to us when we are underwater. Nothing is really “distorted”, per se. Sound waves simply cause water molecules to vibrate differently.
OK, so the important part of this mechanism, for the team’s new camera, is these vibrations.
The small device is encased in a special material that produces an electrical signal whenever it is hit by sound waves vibrating through water. These vibrations, in essence, also make it vibrate. Then the vibrations are converted from mechanical energy to electrical energy, and voila – a constant power underwater camera.
Additionally, to keep the hardware light – so the camera doesn’t eat away at its power – the team used off-the-shelf imaging sensors and cheap flash instruments that can only capture live images. shades of grey. From there, they used some sort of old-fashioned way to get a color image.
“When we were kids in art class, we were taught that we could create any color using three basic colors. The same rules apply to the color images we see on our computers. We just need to red, green and blue — these three channels — – to construct color images,” Waleed Akbar, an MIT researcher and co-author of the study, said in a statement.
First, the camera captures the image with a specially designed red LED light filter, then again with a blue filter and again with a green filter. Together you get the complete picture. Finally, all image data is encoded in computer language, i.e. ones and zeros, and here is the kicker.
It is sent back to a receiver as sound waves.
The camera receiver essentially transmits its own sound waves to the camera, and then the camera can either reflect the waves or completely absorb them. Altogether this creates a sort of binary code to tell the receiver what the image data actually is.
“This whole process, since it only requires a single switch to convert the device from a non-reflective to a reflective state, consumes five orders of magnitude less power than typical underwater communication systems” said MIT researcher Sayed Saad Afzal in a statement.
Currently, however, the camera only has a maximum transmission range of 40 meters from the receiver. But the team said they want to increase both that range and the memory capacity of the device in the future.
Eventually, they said, it could potentially capture photos in real time and possibly even stream underwater secrets directly to a computer.