Curvy, shape-adaptive imagers based on printed optoelectronic pixels with a kirigami design

Abstract

Curvy and shape-adaptive imagers with high pixel fill factors and tunable focusing power can be created by transferring an array of ultrathin silicon optoelectronic pixels with a kirigami design onto curvy surfaces using conformal additive stamp printing. Curvy imagers that can adjust their shape are of use in imaging applications that require low optical aberration and tunable focusing power. Existing curvy imagers are either flexible but not compatible with tunable focal surfaces, or stretchable but with low resolution and pixel fill factors. Here, we show that curvy and shape-adaptive imagers with high pixel fill factors can be created by transferring an array of ultrathin silicon optoelectronic pixels with a kirigami design onto curvy surfaces using conformal additive stamp printing. An imager with a 32 x 32-pixel array exhibits a fill factor, before stretching, of 78% and can maintain its electrical performance under 30% biaxial strain. We also develop an adaptive imager that can achieve focused views of objects at different distances by combining a concave-shaped imager printed on a magnetic rubber composite with a tunable lens. 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 with low aberration.