A Bug’s-Eye View
Researchers develop a new camera inspired by insects’ compound eyes
By Liz Sheeley
Even though we’ve developed the ability to shrink down cameras to fit on a phone, the underlying principle of the camera itself hasn’t really progressed. As a camera gets smaller, there’s a trade-off between field-of-view and image quality; the larger the field-of-view, the more distorted an image will be.
Taking inspiration from nature, Professor Roberto Paiella (ECE, MSE) and Assistant Professor Lei Tian (ECE) have developed a new type of camera that mimics the compound eye of insects, such as the fly, to solve this trade-off problem of single-lens system-based cameras. Unlike compound eyes in nature, however, their device is based on a flat rather than curved geometry and operates without lenses. Their work has been published in Nature Communications.
“There’s no standard technology to develop a camera with curved geometry, which has complicated the implementation of cameras directly inspired by the compound eyes of insects,” says Paiella. “Until now, cameras have been flat with a single lens and all the accompanying technology has been built around that standard. We had to introduce a new approach based on nanophotonics to be able to realize our flat lensless design.”
Paiella and Tian wanted to develop a new camera and technology that could eventually be commercialized, so they used standard materials and fabrication processes to construct their prototypes.
To build a flat optoelectronic compound-eye camera, they began by developing novel metasurfaces that would replace the traditional camera lens. Each metasurface is designed to only transmit light coming from certain angles, and reflect the rest. This means that different metasurfaces are responsible for detecting a combination of points within the field of view. That information is collected and then analyzed by a novel algorithm developed by the research team to reconstruct an image.
“We used similar principles to medical imaging analysis for MRI or CT, where the final images are reconstructed from the raw data by a designed transformation,” says Tian.
These novel metasurfaces could also be tweaked to expand into other imaging capabilities, such as polarization vision, which is how many inspects see by sensing the directions of electrical currents.
This new framework is a proof-of-concept design to show the benefits of combining these novel metasurfaces and computational imaging, which together make optoelectronic compound-eye cameras that allow for a wide field-of-view, highly miniaturized dimensions, and great flexibility in the placement of the different metasurfaces on the final product. These properties are ideally suited for application in medical equipment such as endoscopes or swallow-able cameras, or in surveillance and autonomous drones where the camera needs to be particularly small.