Hydraulically Driven Image Sensor

Before It's News, Technology Review: Researchers from Northwestern University and the University of Illinois at Urbana-Champaign have developed a curvilinear eyeball camera which has a 3.5x optical zoom, takes sharp images, is inexpensive to make and is only the size of a nickel.

The research is supposed to be published the week of Jan. 17 by the Proceedings of the National Academy of Sciences (PNAS)and titled:

"Dynamically tunable hemispherical electronic eye camera system with adjustable zoom capability."
Yonggang Huang, John Rogers, Chaofeng Lu, Ming Li, Inhwa Jung, Jianliang Xiao, Viktor Malyarchuk, Jongseung Yoon, Zhuangjian Liu

Earlier eyeball camera designs were incompatible with variable zoom because these cameras have rigid detectors. The detector must change shape as the in-focus image changes shape with magnification. Huang and Rogers and their team use an array of interconnected and flexible silicon photodetectors on a thin, elastic membrane, which can easily change shape. This flexibility opens up the field of possible uses for such a system.

The camera system also has an integrated lens constructed by putting a thin, elastic membrane on a water chamber, with a clear glass window underneath.

Initially both detector and lens are flat. Beneath both the membranes of the detector and the simple lens are chambers filled with water. By extracting water from the detector's chamber, the detector surface becomes a concave hemisphere. (Injecting water back returns the detector to a flat surface.) Injecting water into the chamber of the lens makes the thin membrane become a convex hemisphere.

To achieve an in-focus and magnified image, the researchers actuate the hydraulics to change the curvatures of the lens and detector in a coordinated manner. The shape of the detector must match the varying curvature of the image surface to accommodate continuously adjustable zoom, and this is easily done with this new hemispherical eye camera.

The eyeball camera is said to be of size of a nickel