A tiny jumping spider has inspired a new type of 3D camera that uses very little power while still producing detailed depth maps in real time.
Engineers at Northwestern University developed the device, called SpiderCam, by studying how jumping spiders judge distances before making their remarkably accurate leaps.
The researchers believe the technology could one day help power wearable devices, robots, drones, and other battery-operated systems that need to understand their surroundings without draining energy.
Unlike most animals, jumping spiders have a unique visual system.
Humans have one retina in each eye, but jumping spiders have multiple layers of retinas. Each layer focuses on objects at slightly different distances.
As a result, the spider sees several versions of the same scene at different levels of sharpness.
Scientists believe the spider’s tiny brain compares these differences in focus to estimate how far away an object is. This allows the spider to jump accurately when hunting prey, escaping predators, or moving around its environment.
The Northwestern research team wanted to see if they could use the same idea to build a more efficient depth-sensing camera.
Most modern 3D cameras determine depth by comparing images from different viewpoints or by projecting light onto objects and measuring how the light returns. While effective, these methods often require significant computing power and consume a large amount of energy.
SpiderCam takes a much simpler approach. The camera captures two images of the same scene at the same time, but each image has a slightly different focus setting. A specially designed algorithm then measures small differences in blur between the two images. By analyzing how sharp or blurry objects appear, the system can calculate their distance from the camera.
To keep energy use extremely low, the researchers built the algorithm directly into a specialized computer chip called an FPGA, or field-programmable gate array. This allows the calculations to be performed efficiently without relying on a power-hungry processor.
The result is a camera that can create 3D depth maps at 32.5 frames per second while using only 624 milliwatts of power—less than one watt. According to the research team, this makes SpiderCam the first passive FPGA-based 3D camera system to operate below that threshold.
Because it requires so little energy, the technology could be especially useful in situations where power is limited. Potential applications include wearable devices, assistive technologies, small robots, drones, and augmented reality systems. It could also be useful in remote locations where devices cannot easily be plugged into a power source.
The researchers plan to improve the camera’s optics, increase its field of view, and eventually develop a custom computer chip that could reduce power consumption even further.
By borrowing a clever trick from one of nature’s smallest hunters, the team has shown that advanced 3D vision does not have to come with a high energy cost.
