Fabrication of Waterproof Artificial Compound Eyes with Variable Field of View Based on the Bioinspiration from Natural Hierarchical Micro–Nanostructures

Planar and curved microlens arrays(MLAs)are the key components of miniaturized microoptical systems.In order to meet the requirements for advanced and multipurpose applications in microoptical field,a simple manufacturing method is urgently required for fabricating MLAs with unique properties,such as waterproofness and variable field-of-view(FOV)imaging.Such properties are beneficial for the production of advanced artificial compound eyes for the significant applications in complex microcavity environments with high humidity,for instance,miniature medical endoscopy.However,the simple and effective fabrication of advanced artificial compound eyes still presents significant challenges.In this paper,bioinspired by the natural superhydrophobic surface of lotus leaf,we propose a novel method for the fabrication of waterproof artificial compound eyes.Electrohydrodynamic jet printing was used to fabricate hierarchical MLAs and nanolens arrays(NLAs)on polydimethylsiloxane film.The flexible film of MLAs hybridized with NLAs exhibited excellent superhydrophobic property with a water contact angle of 158°.The MLAs film was deformed using a microfluidics chip to create artificial compound eyes with variable FOV,which ranged from 0°to 160°.

Simple and High-Efficiency Preparation Method of Biometric 3D Artificial Compound Eyes for Wide-Field Imaging

Three-dimensional(3D)artificial compound eyes(ACEs)are helpful for wide field-o-fview imaging and sensing system applications.However,existing batch preparation methods are technically challenging.A bio-inspired,simple,and high-efficiency batch preparation method is proposed,which involves bonding a sticky microlens array(MLA)polydimethylsiloxane(PDMS)film to an elastic PDMS hemisphere under pressure,followed by abrupt pressure removal.Characterizations from a scanning electron microscope and laser scanning confocal microscope show that 3D ACEs prepared using the proposed method have high numbers of uniformly distributed ommatidia with a high-quality finish.Furthermore,optical imaging investigations demonstrate that the proposed preparation method can achieve clear,distortionfree imaging with a wide field-of-view(up to 140.2°).

Multi-aperture optical imaging systems and their mathematical light field acquisition models

Inspired by the compound eyes of insects,many multi-aperture optical imaging systems have been proposed to improve the imaging quality,e.g.,to yield a high-resolution image or an image with a large field-ofview.Previous research has reviewed existing multi-aperture optical imaging systems,but few papers emphasize the light field acquisition model which is essential to bridge the gap between configuration design and application.In this paper,we review typical multi-aperture optical imaging systems(i.e.,artificial compound eye,light field camera,and camera array),and then summarize general mathematical light field acquisition models for different configurations.These mathematical models provide methods for calculating the key indexes of a specific multiaperture optical imaging system,such as the field-of-view and sub-image overlap ratio.The mathematical tools simplify the quantitative design and evaluation of imaging systems for researchers.