STUDY OF ARTIFICIAL EYES HAVING HIGH STRENGTH AND LOW DENSITY

The artificial eyes having high strength, low density and naturalmovement, which are made from hydroxyapatite and bioactive glass havebeen utilized ef- fectively in clinic. The technology of compoundinghydrox- yapatite, melting bioactive glass and making he artificaleyes are stated in this paper. In animal test, the bioactivity andbiocompatibility of the material making the artificial eyes areexamined by histological observation, SEM XRD and electronic probe.At the same time, application of the artificial eyes in clinic arealso introduced.

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°).

Self-powered transparent photodetector for subretinal visual functions of wide-field-of-view and broadband perception

Natural photoreceptors enable color vision in humans,wherein the eyes detect colors and their corresponding intensities via cone and rod photoreceptors,respectively.Herein,we developed an artificial broadband photoreceptor with light-color intensity detection similar to that of natural photoreceptors.The developed photoreceptor operates in the self-powered mode and is capable of broadband perception(365–940 nm).The designed metal-oxide heterojunction(n-ZnO/p-NiO)photoreceptor with a thin tin sulfide layer embedded in between is capable of perceiving various colors.It exhibits good transparency in the visible range and displays excellent integration with flexible substrates,highlighting its potential for use in flexible electronics.The fabricated structure has an exceptional response time(≈1 ms)and a wide-field-of-view(150?)compared to the human eye's sensing range(50–100 ms and 108?).The transparent photorecep-tor mimics cones and rods to detect a various wavelength-dependent signals and explicitly differentiate between the intensities of the detected signals,respectively.This is further illustrated by employing the developed photoreceptor to detect colors in real time by generating unique signals corresponding to each color.The demonstration provides the proof of concept for self-biased flexible bioelectronics emulating high-performing visual functions of artificial eyes.

Investigation of Ionic Polymer Metal Composite Actuators Loaded with Various Tetraethyl Orthosilicate Contents

Ionic Polymer Metal Composite （IPMC） can be used as an electrically activated actuator, which has been widely used in artificial muscles, bionic robotic actuators, and dynamic sensors since it has the advantages of large deformation, light weight, flexibility, and low driving voltage, etc. To further improve the mechanical properties of IPMC, this paper reports a new method for preparing organic-inorganic hybrid Nafion/SiO2 membranes. Beginning from cast Nation membranes, IPMCs with various tetraethyl orthosilicate （TEOS） contents were fabricated by electroless plating. The elastic moduli of cast Nation membranes were measured with nano indenters, the water contents were calculated, and the cross sections of Nation membranes were observed by scanning electron microscopy. The blocking force, the displacement, and the electric current of IPMCs were then measured on a test apparatus. The results show that the blocking force increases as the TEOS content gradually increases, and that both the displacement and the electric current initially decrease, then increase. When the TEOS content is 1.5%, the IPMC shows the best improved mechanical properties. Finally, the IPMC with the best improved performance was used to successfully actuate the artificial eye and tested.

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.