Nick Carne
Yes, that is a beetle wearing a camera backpack. Not because it needs to: just because it can.
Or, more accurately, so that researchers at the University of Washington, US, can show that it’s possible.
Shyam Gollakota and colleagues have built a camera that weighs just 250 milligrams – a tenth that of a playing card – yet is capable, they say, of taking high-resolution video and streaming it to a smartphone at one to five frames per second.
It sits on a mechanical arm that allows it to pivot 60 degrees to shoot panoramas or tracking shots, yet it does this while expending a minimal amount of energy. And that’s the whole point of the exercise.
Most small cameras use a lot of power to shoot in high-res and wide-angle, meaning they need relatively large batteries, which are too heavy for insects or insect-sized robots – thus making wireless vision impossible, says Gollakota.
Studying insects might have made it possible.
“Similar to cameras, vision in animals requires a lot of power,” says Sawyer Fuller, co-author of the team’s paper in the journal Science Robotics.
“It’s less of a big deal in larger creatures like humans, but flies are using 10 to 20% of their resting energy just to power their brains, most of which is devoted to visual processing. To help cut the cost, some flies have a small, high-resolution region of their compound eyes.
“They turn their heads to steer where they want to see with extra clarity, such as for chasing prey or a mate. This saves power over having high resolution over their entire visual field.”
To mimic an insect’s vision, the researchers used an ultra-low-power black-and-white camera that can sweep across a field of view. When they apply a high voltage, the mechanical arm bends and moves the camera to the desired position.
Unless more power is applied, the arm stays at that angle for about a minute before relaxing back to its original position. This is similar, the researchers say, to the way people can only keep their head turned for a short period before returning to a more neutral position.
“We can track a moving object without having to spend the energy to move a whole robot,” says co-lead author Vikram Iyer. “These images are also at a higher resolution than if we used a wide-angle lens, which would create an image with the same number of pixels divided up over a much larger area.”
The researchers attached their system to two different types of beetles that have been known to carry loads heavier than half a gram. All were able to move and navigate freely – and lived to tell the tale.
“We added a small accelerometer to our system to be able to detect when the beetle moves. Then it only captures images during that time,” says Iyer.
“If the camera is just continuously streaming without this accelerometer, we could record one to two hours before the battery died. With the accelerometer, we could record for six hours or more, depending on the beetle’s activity level.”
The researchers are excited by the potential of their system – both in robots and to get an insect’s view of the world – but also conscious of the privacy implications around an army of very small paparazzi.