Electronic Eye
Stretchable circuits enable a high-quality spherical camera

Source: “A hemispherical electronic eye camera based on compressible silicon optoelectronics”
John Rogers et al.
Nature 454: 748-753

Results: Using a stretchable electronic circuit, researchers at the University of Illinois at Urbana-Champaign have designed a curved, 256-pixel camera sensor that produces small but high-quality images using a simple lens.

Why it matters: Unlike the human eye, with its single lens, camera lenses require multiple components to correct for distortions and aberrations that result from focusing light onto a flat surface, such as a strip of film or a conventional digital light sensor. A curved sensor doesn’t require as many lens components to capture high-quality images, so lenses can be simpler and lighter.

Methods: On a silicon wafer, the researchers used conventional lithography to fabricate an array of 500-by-500-micrometer silicon light sensors connected by metal ribbons. They removed the array from its silicon substrate by means of a chemical process. Next, the researchers used a mold to fabricate a film of flexible silicone in the shape of a bowl. Then they stretched the film flat and applied the sensor array. When they released the silicone, it returned to its bowl-like shape, curving the sensor array in the process. The metal ribbons, which are thin enough to be flexible, allow the array to bend without breaking. Finally, the researchers incorporated the array into a camera with a simple lens and electronics.

Next steps: The researchers are trying to make higher-­resolution cameras that have more sensors, and they hope to use different types of curved surfaces to optimize the imaging.