A battery-free, wireless and underwater camera: MIT technology to have energy at the bottom of the sea

The seabed is practically uncharted territory. NASA has underwater robots but even so the vast majority have never been observed. In fact, water prevents us from knowing better the surface of our planet. Even from Mars we have a better picture. In addition to accessing those depths, one of the problems is how to get enough power down there. Batteries can be added, but it is added weight.

Now from MIT they offer a solution. In a article published in Nature describe the creation of the first battery-free camera intended for marine exploration. A wireless camera, which works underwater and where batteries are not needed.

Getting energy from sound

It’s okay if it doesn’t have a battery, but the power has to come from somewhere. According to the MIT engineers, this camera is more than 100,000 times more efficient than the rest of the aquatic chambers. And it is a camera capable of taking color photos, even in the darkness of the seabed. Not only that, but it is also wireless, which Lets send these images through the water.

How do you get the energy then? The key is in the sound. They convert the mechanical energy of sound waves traveling through water into electrical energy., which in turn is used for the electronics of the camera. Once the image is processed, the camera again uses sound waves to send this data. And then already from the center of the surface you can reconstruct the image.

“We are building models but we are missing data for more than 95% of the ocean. This technology could help us build more accurate models and better understand how climate change affects the underwater world,” explains Fadel Adib, director of the Signal Kinetics group at MIT. MediaLab.

The camera itself does not need a battery or a direct source of energy because it is when it receives the sound waves that the necessary impulse is generated. As they explain, the camera can function for weeks before needing to resurface. And this autonomy is key to enabling more effective marine exploration.

To transform sound into energy, the camera uses piezoelectric material transducers that are placed around its exterior. When a mechanical force (that of sound) is applied to them, an electrical signal is produced.

The most interesting thing is that this sound force can come from any source. Be it the seabed itself or a passing ship. The camera is able to retain this energy to take photos. The difficulty lies in obtaining color photos. For this they created a dedicated flash.

The researchers have a working prototype and have in fact already used it to study an African starfish. Now they want to expand the memory of the camera, find out if they could record video and extend the range, since the wireless capacity is currently limited to 40 meters.

The battery-less devices are becoming more common and we are even seeing them with commercial pretensions. It is the case of the Powerfoyle technology or OPPO’s plan. The first works with solar charging; the second is based on radiofrequency charging. This MIT camera is based on mechanical sound waves. Basically they are based on the same idea: trying to get energy in an original way beyond pulling the classic battery.

Via | MITNews