Elastomers help create 'bionic eye'

ERJ staff report (DS)

Chicago, Illinois -- Researchers at two Universities in Illinois have developed an artificial eye which relies on an elastomeric membrane to act as the 'retina'.

Yonggang Huang, Professor of Civil and Environmental Engineering and Mechanical Engineering at Northwestern University's McCormick School of Engineering and Applied Science, has collaborated with John Rogers, the Flory-Founder Chair Professor of Materials Science and Engineering at the University of Illinois at Urbana-Champaign, to create an array of silicon detectors and electronics that can be conformed to a curved surface. Like the human eye, the curved surface can then act as the focal plane array of the camera, which captures an image.

The results of this research will be published as the cover story in the Aug. 7 issue of the journal Nature.

"The advantages of curved detector surface imaging have been understood by optics designers for a long time, and by biologists for an even longer time," Huang says. "That's how the human eye works -- using the curved surface at the back of the eye to capture an image."

Rogers created a hemispherical transfer element made out of a thin elastomeric membrane that can be stretched out into the shape of a flat drumhead. In this form, planar (flat) electronics can be transferred onto the elastomer. Popping the elastomer back into its hemispheric form enables the transfer of the electronics onto a hemispherical device substrate.

The researchers also designed the array so that the silicon component of each device is sandwiched in the middle of two other layers, the so-called natural mechanical plane. That way, while the top layer is stretched and the bottom layer is compressed, the middle layer experiences very small stress.

The experimental unit is limited to 256 pixels, though the technique can be scaled to much larger devices, said the researchers.

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Press release from Northwestern University

Article from Nature