Fabrication of a bionic compound eye on a curved surface by using a self-assembly technique

Microlens arrays on curved surfaces are regarded as critical elements of bionic compound eyes (BCEs), which exhibit the comparative advantages of a wide field of view and tracking fast-moving objects. However, the fabrication of a curved microlens array is still challenging. Along these lines, in this work, a straightforward, rapid, and low-cost technique for the fabrication of curved microlens arrays is reported by using the self-assembly technique. A reactive ion etching process treated the surface of the curved polydimethylsiloxane (PDMS) substrate to generate a hydrophobic-hydrophilic pattern. Then, the curved microlens array can be realized by dewetting a liquid glue onto the substrate using the dip-coating method and followed by crosslinking. The proposed BCE structure consists of 2400 microlenses (400 - mu m diameter and 440 - mu m center distance) arranged in a hexagonal configuration on a curved PDMS surface (34 - mm diameter and 40.4 - mm curvature radius). A field-of-view of 50 degrees was demonstrated, which has potential applications in various fields including imaging sensors, medical diagnostics, machine vision systems, and photodetectors. (C) 2022 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement

Automated summary

This work presents a straightforward, rapid, and low-cost technique for fabricating curved microlens arrays on polydimethylsiloxane (PDMS) substrates using the self-assembly technique. The proposed technique involves a reactive ion etching process followed by dip-coating and crosslinking to create a hydrophobic-hydrophilic pattern and realize the curved microlens array. The fabricated bionic compound eye structure showed a wide field of view and has potential applications in imaging sensors, medical diagnostics, machine vision systems, and photodetectors.