SEATTLE — Researchers at the University of Washington have created a wireless steerable camera that can ride aboard insects.
The camera can give a first-person view of what’s happening from an actual live insect, or create vision for small robots, researchers said.
“Vision is so important for communication and for navigation, but it’s extremely challenging to do it at such a small scale. As a result, prior to our work, wireless vision has not been possible for small robots or insects,” said senior author Shyam Gollakota, a UW associate professor in the Paul G. Allen School of Computer Science & Engineering.
Researchers say the camera sits on a mechanical arm that can pivot 60 degrees and streams video to a smartphone at 1 to 5 frames per second.
The system weighs about 250 milligrams, or about one-tenth of the weight of a playing card. The camera and arm are controlled via Bluetooth from a smartphone from a distance up to 120 meters away.
To demonstrate the versatility of the system, researchers mounted it on top of live beetles and insect-sized robots. The results were published Wednesday in Science Robotics.
Small cameras like those used in smartphones use a lot of power to capture wide-angle, high resolution photos that don’t work at the insect scale, researchers said. The cameras are lightweight, but the batteries needed to support them are too big and heavy for insects or insect-sized robots.
"Similar to cameras, vision in animals requires a lot of power," said co-author Sawyer Fuller, a UW assistant professor of mechanical engineering.
Researchers said they used a tiny, ultra-low-power black-and-white camera to help mimic an animal’s vision. The camera can sweep across a field of vision with the help of the mechanical arm.
The arm moves when the team applies a high voltage, researchers said. The arm stays at that angle before going back to its original position unless more power is applied.
Researchers said it is similar to how people can keep their head turned in one direction for only a short period of time before returning it to a more neutral position.
“We can track a moving object without having to spend the energy to move a whole robot,” said co-lead author Vikram Iyer, a UW doctoral student in electrical and computer engineering. “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.”
Researchers said they attached the removable system to the backs of a death-feigning beetle and a pinacate beetle.
Similar beetles have been known to be able to carry loads heavier than half a gram, the researchers said.
"We made sure the beetles could still move properly when they were carrying our system," said co-lead author Ali Najafi, a UW doctoral student in electrical and computer engineering. "They were able to navigate freely across gravel, up a slope and even climb trees."
The beetles also lived for at least a year after the experiment ended, researchers said.
"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," Iyer said. "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."
Researchers said they also used their camera system to design the world’s smallest terrestrial, power-autonomous robot with wireless vision.
The insect-sized robot uses vibrations to move and consumes almost the same power as low-power Bluetooth radios need to operate, researchers said.
However, the team said they found that the vibrations shook the camera and produced distorted images. They solved the issue by having the robot stop momentarily, take a picture and then resume its journey.
Researchers acknowledged that lightweight and low-power mobile cameras come with a new set of privacy risks.
“As researchers we strongly believe that it’s really important to put things in the public domain so people are aware of the risks and so people can start coming up with solutions to address them,” Gollakota said.