A binocular vision system consisting of two artificial compound eyes, each containing 37 light sensors
Zhiyong Fan et al. (2024)
Cameras inspired by the compound eyes of insects enable an extremely wide field of view without expensive lenses, potentially offering cheap, simple and lightweight visual sensors for navigation or tracking in robots and driverless cars.
Insects like dragonflies have eyes that, in pairs, provide an almost 360-degree field of vision and help them to deftly evade predators. Their eyes are composed of many ommatidia, which are essentially tubes with a simple lens at one end and a basic photoreceptor at the other. Their vision is made up of pixel-like inputs from large bundles of these ommatidia.
Creating cameras that can affordably achieve the same thing, either by covering a hemisphere with image sensors or by creating multiple lenses to direct light onto a central sensor, has proved challenging. Now Zhiyong Fan and his colleagues at the Hong Kong University of Science and Technology have replicated the architecture of insect eyes using nanowires made from a crystal material called perovskite, without the need for precisely manufactured lenses.
Their design consists of a 3D-printed hemisphere around 2 centimetres across with 121 openings, each 1 millimetre in diameter, that act like a simple pinhole camera. In each hole, a perovskite nanowire directs light from a very narrow field of view directly onto a light sensor, and electronics combine the results into a single frame. The artificial eye can generate images with a field of view of 140 degrees, and an overlapping pair can extend this to 220 degrees.
Fan says that this could be a huge boost in certain robotics applications, such as in a swarm of drones flying in close formation. “They need to maintain a distance, maybe a few metres away from each other, so they need to know the precise location and the relative speed they are approaching each other and moving away from each other,” he says. “So the compound eye is important; it has the wider field of view and also sensitivity for motion.”
The researchers also built a pair of smaller artificial compound eyes with 37 light sensors. They fitted a quadcopter drone with this system and were able to use it to track a robotic dog on the ground.
Fan says the compound eye design also benefits from being simple, light and cheap, but it won’t fully replace traditional cameras. Instead, he thinks the devices will provide supplemental data that is useful for robots and other machines, such as self-driving cars.
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