The ocean has been a greater mystery than Mars and the Moon. What lies deep beneath the surface remains an unanswered question, as it has for centuries. There appears to be a window for its solution as technology advances.
While, Revea, a US-based precision skincare company raised $6 million in seed II funding for developing a smartphone camera feature to reimagine skincare with AI, now a group of MIT engineers are developing an ultra-efficient battery-free, wireless underwater camera. The underwater camera was created by a team of US engineers and is about 100,000 times more energy-efficient than other underwater cameras. It is wireless, battery-free, and powered by sound.
Even in low-light conditions underwater, the camera captures colour images and wirelessly transmits them.
Battery-free cameras
The autonomous camera uses sound waves travelling through the water to convert mechanical energy into electrical energy to power its imaging and communications hardware.
Further, the camera uses sound waves to transmit data to a receiver that reconstructs the image after the image has been captured and encoded.
According to a team from the Massachusetts Institute of Technology (MIT) in the US, the camera could operate without a power source for weeks on end before being retrieved, allowing researchers to search remote areas of the ocean for new species.
Additionally, it could be used to take pictures of ocean pollution or track the well-being and development of fish raised in aquaculture farms.
“We are building climate models, but we are missing data from over 95 per cent of the ocean. This technology could help us build more accurate climate models and better understand how climate change impacts the underwater world,” said Fadel Adib, associate professor in the Department of Electrical Engineering and Computer Science and senior author of the paper.
Transducers made of piezoelectric materials are positioned all over the outside of the camera to obtain energy.
When a mechanical force is applied to “piezoelectric” materials, an electric signal is generated.
The transducers vibrate and change the mechanical energy of a sound wave passing through the water into electrical energy when it strikes them.
“Those sound waves might have originated from a passing ship or some underwater life. According to the study, the camera stores captured energy until it has accumulated enough to power the electronics that take photos and transmit data.
After being captured, image data are converted to bits (1s and 0s) and transmitted one bit at a time using a technique known as “underwater backscatter.”
How does it work?
The camera serves as a mirror to reflect the sound waves that are transmitted by the receiver through the water. The camera either sends a wave back to the receiver by reflecting it or transforms its mirror into an absorber to prevent reflection.
The red, green, and blue colours of light are reflected in the white portion of each photograph, despite the fact that the image appears to be black and white.
The colour image can be recreated by combining the image data during post-processing.
The camera was tested by the researchers in a variety of underwater settings. In one, they managed to photograph in colour plastic bottles drifting in a pond in New Hampshire.
The device will now be improved so that it can be used in practical settings.
