Fabrication of a light screen-aperture integrated flexible thin film micro-lens array for a biomimetic superposition compound eye

Micro-lens array, an artificial compound eye vision system, provides a wide field of view and multi-perspective view. However, it has not been adopted as a computer vision application due to its limited visible range and high optical interference. In this research, a novel fabrication method for the flexible polydimethylsiloxane micro-lens array with a polytetrafluoroethylene light screen-aperture integrated layer was established by the simple protrusion method. The integrated layer provided longer visible range by one meter while maintaining the wide field-of-view of 100 °. The resulting images were used for obtaining depth information of a target as an example and for analyzing the rectangular and hexagonal arrangements of the micro-lenses for the future applications. With the improved visual range, wide field-of-view and flexibility, the fabricated micro-lens array can be applied to the small and curved CMOS image sensors in the future.

Self-Assembled Microlens Array with Controllable Focal Length Formed on a Selective Wetting Surface

We report a microlens array with a controllable focal length that is based on a selective wetting surface. A substrate modified with a hydrophobic layer that has an array of microholes exhibits different wettability for inside holes (hydrophilic) versus outside holes (hydrophobic). When liquid flows over the surface, a small amount of liquid is adhered to hydrophilic holes and forms a lens-shaped droplet array that self-assembles because of surface tension. A large-sized plano-convex lens array that has good uniformity is obtained via the blade coating method, and controlling the amount of liquid enables control of the focal length. Our self-assembled microlens array has the merits of high optical performance, a simple fabrication procedure, and good mechanical stability, and thus, it has potential applications in imaging processing, light extraction, protein detection, light-emitting diodes, sensors, and displays.