Cunjiang Yu is the Bill D. Cook Associate Professor of Mechanical Engineering, University of Houston. He reports on the creation of an adaptable camera that can improve image quality for endoscopes and night-vision goggles as well as artificial compound eyes and fisheye cameras.Yu reports that curvy images are either rigid but incompatible with tunable focal surfaces or flexible, but have low pixel density and fill factors. The new imager with kirigami technology has a 78% pixel fill factor before stretching and can maintain its optoelectronic performance even when it is biaxially stretched by 30%.Modern digital cameras that use flat, rigid imaging sensors need bulky lenses to correct optical aberrations. Curvy cameras, which are similar to human eyes, can be used with one lens, correcting aberrations, and providing other advantages such as a large field of view and small size.Yu demonstrated that it is possible to create curvy cameras and shape-adaptive cameras by using conformal additive stamping (CAS) printing. This technology was developed in Yu's lab.Kirigami, a Japanese art of paper cutting similar to origami or paper folding, is called paper cutting. Yu used the kirigami principle to make cuts on thin sheets of imaging sensors. This allows it stretch and curve. This new kirigami structure is more flexible than other stretchable structures like thin open-mesh serpentine and island-bridge. It has a higher fill factor which means it retains high pixels density. This creates better images.Yu not only makes the camera curvy but also allows it to be shape-adaptive. This means it can capture objects at different distances with clarity.The new adaptive imager is able to focus on objects at different distances using a concave-shaped camera printed onto a magnetic rubber sheet and a tunable lens. The focal length and curvature of an imager can be adjusted to achieve adaptive optical focus. This allows for clear images of both near and far objects with low aberration. Yu is also the principal investigator at UH's Texas Center for Superconductivity.An elastomeric (or stretchy) balloon is inflated to do CAS printing. It has a sticky coating. The balloon is used to stamp prefabricated electronic components onto various surfaces.
