Kirigami-Inspired Imaging Sheets Offer a Curved, Eyeball-Like Camera with Tunable Optical Focus

Researchers at the Universities of Houston, Colorado, and Wisconsin-Madison, have come up with a way to make a better camera — taking inspiration from the curvature of the human eye and the Japanese art of kirigami, or paper cutting.

"Existing curvy [camera] imagers are either flexible but not compatible with tunable focal surfaces, or stretchable but with low pixel density and pixel fill factors," Cunjiang Yu, Bill D. Cook Associate Professor of Mechanical Engineering at the University of Houston, explains of the problem he and colleagues sought to solve.

“The new imager with kirigami design has a high pixel fill factor, before stretching, of 78 percent and can retain its optoelectronic performance while being biaxially stretched by 30 percent.”

The inspiration for the camera's construction comes from the Japanese art of paper cutting, kirigami — closely aligned to origami, the art of folding paper without cuts. Taking a sheet of imaging sensors, the team made cuts which allow the sheet to stretch and curve - without losing its high pixel density.

"The new adaptive imager can achieve focused views of objects at different distances by combining a concave-shaped camera printed on a magnetic rubber sheet with a tunable lens," Yu adds. "Adaptive optical focus is achieved by tuning both the focal length of the lens and the curvature of the imager, allowing far and near objects to be imaged clearly with low aberration."

It's not the first time kirigami techniques have been used in the field of electronics: Last year MIT showed off a kirigami-based sensor for a robotic elephant trunk, while a team at Harvard's John A. Paulson School of Engineering and Applied Sciences (SEAS) used the same techniques to produce "programmable balloons."

The team's work has been published under closed-access terms in the journal Nature Electronics.