Focus-tunable real-time imaging system based on ultrathin perovskite curved image sensor with hierarchical mesh design

The human visual system's real-time focus-tunable imaging capability has inspired curved imaging system development. However, curved image sensors mimicking the human retina typically lack tunable curvature to match the curved Petzval surface throughout the focus-tunable range. Here, we propose a focus-tunable real-time curved imaging system based on a tunable-curvature perovskite curved image sensor. Using parylene C film for waterproofing and encapsulation, the ultrathin perovskite curved image sensor with the hierarchical mesh design is demonstrated, which conforms to spherical surfaces of different radii while maintaining mechanical stability during deformation. The image sensor exhibits low detection limit (10 nanowatts per square centimeter) and long-term stable dynamic photoresponse. Combining the image sensor with a tunable lens achieves clear images at different distances via simultaneously adjusting both sensor and lens radii. Furthermore, through integrating image sensor with a readout matrix and wireless data collection component, the real-time imaging system is demonstrated with real-time focus-tunable imaging capabilities.