To overcome these issues, a team of researchers from Korea and the US, including Professor Young Min Song from the Gwangju Institute of Science and Technology in Korea, have now designed a new artificial vision system with omnidirectional imaging capability, which can operate in both aquatic and terrestrial environments. Their study was made available online on July 12, 2022 and published in Nature Electronics on July 11, 2022. “Research into bio-inspired vision often leads to a new development that did not exist before. This, in turn, enables a deeper understanding of nature and ensures that the developed imaging device is both structurally and functionally efficient,” says Professor Song. explaining his motivation behind the study. The inspiration for the system came from the crab (Uca arcuata), a semi-terrestrial crab species with amphibious imaging capability and a 360° FOV. These remarkable features result from the ellipsoidal eye stalk of the crab’s compound eyes, which allows for panoramic imaging, and the flat corneas with a graded refractive index profile, which allows for amphibious imaging. Consequently, the researchers developed a vision system consisting of an array of planar microlenses with graded refractive index profiles embedded in a flexible comb-shaped silicon photodiode array and then mounted on a spherical structure. The graded refractive index and flat surface of the microlens were optimized to compensate for defocusing effects due to changes in the external environment. Simply put, light rays traveling through different media (corresponding to different indices of refraction) are made to focus at the same point. To test the capabilities of their system, the team performed visual simulations and imaging demonstrations in air and water. Amphibious imaging was performed by submerging the device halfway in water. To their delight, the images produced by the system were clear and free of distortion. The team further demonstrated that the system had a panoramic field of view, 300o horizontally and 160o vertically, in both air and water. In addition, the spherical base was only 2 cm in diameter, making the system compact and portable. “Our vision system could pave the way for 360° omnidirectional cameras with virtual or augmented reality applications, or an all-weather vision for autonomous vehicles,” speculates Professor Song excitedly. Story source: Material provided by GIST (Gwangju Institute of Science and Technology). Note: Content can be edited for style and length.
