Compound Eye Research Articles

A compound eye-like morphology formed through hexagonal array of hemispherical microparticles where an alkyl-fullerene derivative self-assembled at atmosphere-sealed air/water interface

Self-assembly processes are widely used in nature to form hierarchically organized structures, prompting us to investigate such processes at the macroscopic scale. We report an unprecedented approach toward the self-assembly of alkyl-fullerene (C60) derivatives into a hexagonal array of hemispherical microparticles akin to the morphology of a compound eye. The method includes casting solvated alkyl-C60 compound on an air/water interface followed by controlled evaporation of the solvent under atmosphere-sealed conditions. This leads to the formation of a thin film floating on water with a diameter of up to 1.3 centimeters and exhibiting a hexagonally-packed hemispherical structure with a diameter of approximately 38 µm. Various measurements of the formed film reveal that amorphousness is necessary for suppressing uncontrollable crystallization, which affects the microparticle size and film formation mechanism. We tested the feasibility of this approach for the self-assembly of a relatively common C60 derivative, [6,6]-phenyl-C61-butyric acid methyl ester (PC61BM), resulting in the formation of a film with a similar pattern of hexagonally-packed larger microparticles approximately 152 µm in size of diameter.

Reciprocal Coupling of Circadian Clocks in the Compound Eye and Optic Lobe in the Cricket Gryllus bimaculatus

Reciprocal Coupling of Circadian Clocks in the Compound Eye and Optic Lobe in the Cricket Gryllus bimaculatus

All-in-Focus Three-Dimensional Reconstruction Based on Edge Matching for Artificial Compound Eye

An artificial compound eye consists of multiple apertures that allow for a large field of view (FOV) while maintaining a small size. Each aperture captures a sub-image, and multiple sub-images are needed to reconstruct the full FOV. The reconstruction process is depth-related due to the parallax between adjacent apertures. This paper presents an all-in-focus 3D reconstruction method for a specific type of artificial compound eye called the electronic cluster eye (eCley). The proposed method uses edge matching to address the edge blur and large textureless areas existing in the sub-images. First, edges are extracted from each sub-image, and then a matching operator is applied to match the edges based on their shape context and intensity. This produces a sparse matching result that is then propagated to the whole image. Next, a depth consistency check and refinement method is performed to refine the depth of all sub-images. Finally, the sub-images and depth maps are merged to produce the final all-in-focus image and depth map. The experimental results and comparative analysis demonstrate the effectiveness of the proposed method.

Non-invasive recording of electroretinogram from both compound eyes in the cockroach <i>Periplaneta americana L.<i> in response to light stimuli

The paper presents an original method of non-invasive registration of electroretinogram from both compound eyes of an insect. The method demonstrated high reliability and repeatability of the results. Using this method, it was shown that the magnitude of the light responses obtained from mutant cockroaches devoid of screening pigment, pearl, was about 4 times greater than those of wild-type insects. The time to peak of the response decreased with increasing light intensity, both for short-wavelength and long-wavelength stimuli. The pearl cockroaches exhibited a faster time to peak response than wild-type cockroaches; the results of covariance analysis indicate that these differences cannot be fully explained by an increase in the number of photons reaching the photoreceptor membranes and suggest additional differences in the compound eye physiology of mutant and wild-type insects. The positive voltage wave after the end of light stimulation depends on light intensity and reflects hyperpolarization of receptor cells. The photovoltaic effect, which distorts the amplitude and the shape of the response can be eliminated by using a gold wire as a recording electrode.

An ultrawide field-of-view pinhole compound eye using hemispherical nanowire array for robot vision.

Garnering inspiration from biological compound eyes, artificial vision systems boasting a vivid range of diverse visual functional traits have come to the fore recently. However, most of these artificial systems rely on transformable electronics, which suffer from the complexity and constrained geometry of global deformation, as well as potential mismatches between optical and detector units. Here, we present a unique pinhole compound eye that combines a three-dimensionally printed honeycomb optical structure with a hemispherical, all-solid-state, high-density perovskite nanowire photodetector array. The lens-free pinhole structure can be designed and fabricated with an arbitrary layout to match the underlying image sensor. Optical simulations and imaging results matched well with each other and substantiated the key characteristics and capabilities of our system, which include an ultrawide field of view, accurate target positioning, and motion tracking function. We further demonstrate the potential of our unique compound eye for advanced robotic vision by successfully completing a moving target tracking mission.

Research on key technology of cooled infrared bionic compound eye camera based on small lens array

Traditional 2D imaging technologies are limited by the need for a large field of view and their sensitivity to small target motion. Inspired by the characteristics of insect compound eye structure, we propose an infrared bionic compound eye camera based on a small lens array. The camera is composed of 61 small lens arrays mounted on a curved spherical shell and a relay optical system. The imaging device is a high-performance cooled mid-wave infrared detector. This is an innovative design for an infrared biomimetic compound eye camera system that provides a wide field of view and all-day detection capability. Aimed to meet the specified requirements. The optical system achieves a 100% cold-membrane match between the infrared optical system and the cooled detector, and the relay optical system optimizes the large-field aberration by introducing a higher-order aspheric surface and modifying the geometric surface of the lenses. Our entire system enables an observation field angle of 108∘×108∘\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$108^\\circ \ imes 108^\\circ$$\\end{document}. The experiments showed that the image quality of the system is high, each ommatidium was effective within the imaging range of the compound eye camera, resulting in an improved signal-to-noise ratio in various scenes.

Stereoscopic artificial compound eyes for spatiotemporal perception in three-dimensional space.

Arthropods' eyes are effective biological vision systems for object tracking and wide field of view because of their structural uniqueness; however, unlike mammalian eyes, they can hardly acquire the depth information of a static object because of their monocular cues. Therefore, most arthropods rely on motion parallax to track the object in three-dimensional (3D) space. Uniquely, the praying mantis (Mantodea) uses both compound structured eyes and a form of stereopsis and is capable of achieving object recognition in 3D space. Here, by mimicking the vision system of the praying mantis using stereoscopically coupled artificial compound eyes, we demonstrated spatiotemporal object sensing and tracking in 3D space with a wide field of view. Furthermore, to achieve a fast response with minimal latency, data storage/transportation, and power consumption, we processed the visual information at the edge of the system using a synaptic device and a federated split learning algorithm. The designed and fabricated stereoscopic artificial compound eye provides energy-efficient and accurate spatiotemporal object sensing and optical flow tracking. It exhibits a root mean square error of 0.3 centimeter, consuming only approximately 4 millijoules for sensing and tracking. These results are more than 400 times lower than conventional complementary metal-oxide semiconductor-based imaging systems. Our biomimetic imager shows the potential of integrating nature's unique design using hardware and software codesigned technology toward capabilities of edge computing and sensing.

Eye development influences horn size but not patterning in horned beetles.

Understanding the origin of novel morphological traits is a long-standing objective in evolutionary developmental biology. We explored the developmental genetic mechanisms that underpin the formation of a textbook example of evolutionary novelties, the cephalic horns of beetles. Previous work has implicated the gene regulatory networks associated with compound eye and ocellar development in horn formation and suggested that horns and compound eyes may influence each other's sizes. Therefore, we investigated the functional significance of genes central to visual system formation in the initiation, patterning, and size determination of head horns across three horned beetle species. We find that while the downregulation of canonical eye patterning genes reliably reduces or eliminates compound eye formation, it does not alter the position or shape of head horns yet does result in an increase in relative horn length. We discuss the implications of our results for our understanding of the genesis of cephalic horns in particular and evolutionary novelties in general.

Bio-inspired foveal super-resolution method for multi-focal-length images based on local gradient constraints

Most existing super-resolution (SR) imaging systems, inspired by the bionic compound eye, utilize image registration and reconstruction algorithms to overcome the angular resolution limitations of individual imaging systems. This article introduces a multi-aperture multi-focal-length imaging system and a multi-focal-length image super-resolution algorithm, mimicking the foveal imaging of the human eye. Experimental results demonstrate that with the proposed imaging system and an SR imaging algorithm inspired by the human visual system, the proposed method can enhance the spatial resolution of the foveal region by up to 4 × compared to the original acquired image. These findings validate the effectiveness of the proposed imaging system and computational imaging algorithm in enhancing image texture and spatial resolution.

Artificial Compound Eye with Tunable Properties for Enhancement in Fluorescence Imaging and Raman Detection

AbstractArtificial compound eye (CE) draws inspiration from nature, offering advanced imaging capabilities and an expansive field of view. In this work, an innovative technique is developed for the creation of CE with tunable dimensions. A solution‐based process is employed that involves in situ polymerization of surface nanodroplets prior to soft lithography to produce CE consisting of millions of ommatidia. The fabricated CE comprised of a densely arranged array of microwells, each with a base radius of 5 µm. Situated on a millimeter‐sized spherical dome, the CE can be tailored to arbitrary dimensions, enhancing its adaptability with a wide angular field of view up to 118°. The CE is used to enhance signal detection in fluorescent compounds, reaching a detection limit of 107 times lower concentration than that without using CEs in bulk solution. The signal enhancement capabilities are further utilized for surface‐enhanced Raman spectroscopy by using a portable handheld device, with an enhancement factor of 2. The fabrication technique underscores the advantages of the approach in simplicity, reproducibility, and efficiency in creating CE. The potential applications of CE may be extended to various domains, such as optical sensing, light‐dependent signal enhancement, motion perception, and medical endoscopy.

Measurement Methods for Droplet Adhesion Characteristics and Micrometer-Scale Quantification of Contact Angle on Superhydrophobic Surfaces: Challenges and Opportunities.

Inspired by nature, superhydrophobic surfaces have been widely studied. Usually the wettability of a superhydrophobic surface is quantified by the macroscopic contact angle. However, this method has various limitations, especially for precision micro devices with superhydrophobic surfaces, such as biomimetic artificial compound eyes and biomimetic water strider robots. These precision micro devices with superhydrophobic surfaces proposed a higher demand for the quantification of contact angles, requiring contact angle quantification technology to have micrometer-scale measurement capabilities. In this review, it is proposed to achieve micrometer-scale quantification of superhydrophobic surface contact angles through droplet adhesion characteristics (adhesion force and contact radius). Existing contact angle quantification techniques and droplet characteristics' measurement methods were described in detail. The advancement of micrometer-scale quantification technology for the contact angle of superhydrophobic surfaces will enhance our understanding of superhydrophobic surfaces.

Eye morphology in four species of tiger beetles (Coleoptera: Cicindelidae)

Compound eyes undoubtedly represent the widespread eye architecture in the animal kingdom. The insects' compound eye shows a wide variety of designs, and insects use their visual capacity to accomplish several tasks, including avoiding enemies, searching for food and shelter, locating a mate, and acquiring information about the environment and its surroundings. Broad literature data support the concept that visual ability lies in the way the eyes are built. Since the resolution and sensitivity of the compound eye are partly determined by the density of the ommatidia and the size of the facets. Morphological parameters of the compound eyes could influence the function of the visual organ and its capacity to process information, also representing a sensitive indicator of different habitat demands. In this study, we compared compound eyes' parameters in four closely related species of tiger beetles to disclose differences arising from different habitats. Furthermore, to investigate whether there are consistent intersexual differences, we also compared the most relevant parameters of the eye in males and females of four selected species. Our results show sex-related and interspecific differences that occur in examined species.

Bionomy Description of Julodis speculifer Laporte, 1835 in South Iraq

Objective: The beetle family Buprestidae (jewel beetles) includes about 15,000 species and has a number Worldwide ‎distribution. Julodis speculifer is one of these species, for the first time Recorded in south Basrah province. Methods: Collected specimens were from March 2022 to November 2022, AL-Zubair region, The main characters adopted: compound eyes, carving face, antennal cavities, flagellum, scape, pronotum, scutellum, elytra, membrane wing, abdomen, and ‎male genitalia. Results: Body adult beetles Large sized, elongated, oval in shape, resembling a boat, slightly convex at the dorsal, brown to shiny copper, with white spots in the form of parallel lines on all parts of the dorsal surface body, all parts of the body are covered with a light white fluff. The male is smaller in size than the female. Conclusions: They were diagnosed did not have traits that differed from the species recorded in Kuwait, but different subspecies in Saudi Arabia.

α-Synuclein pathology in Drosophila melanogaster is exacerbated by haploinsufficiency of Rop: connecting STXBP1 encephalopathy with α-synucleinopathies.

Syntaxin-binding protein 1 (STXBP1) is a presynaptic protein that plays important roles in synaptic vesicle docking and fusion. STXBP1 haploinsufficiency causes STXBP1 encephalopathy (STXBP1-E), which encompasses neurological disturbances including epilepsy, neurodevelopmental disorders, and movement disorders. Most patients with STXBP1-E present with regression and movement disorders in adulthood, highlighting the importance of a deeper understanding of the neurodegenerative aspects of STXBP1-E. An in vitro study proposed an interesting new role of STXBP1 as a molecular chaperone for α-Synuclein (αSyn), a key molecule in the pathogenesis of neurodegenerative disorders. However, no studies have shown αSyn pathology in model organisms or patients with STXBP1-E. In this study, we used Drosophila models to examine the effects of STXBP1 haploinsufficiency on αSyn-induced neurotoxicity in vivo. We demonstrated that haploinsufficiency of Ras opposite (Rop), the Drosophila ortholog of STXBP1, exacerbates compound eye degeneration, locomotor dysfunction, and dopaminergic neurodegeneration in αSyn-expressing flies. This phenotypic aggravation was associated with a significant increase in detergent-insoluble αSyn levels in the head. Furthermore, we tested whether trehalose, which has neuroprotective effects in various models of neurodegenerative disorders, mitigates αSyn-induced neurotoxicity exacerbated by Rop haploinsufficiency. In flies expressing αSyn and carrying a heterozygous Rop null variant, trehalose supplementation effectively alleviates neuronal phenotypes, accompanied by a decrease in detergent-insoluble αSyn in the head. In conclusion, this study revealed that Rop haploinsufficiency exacerbates αSyn-induced neurotoxicity by altering the αSyn aggregation propensity. This study not only contributes to understanding the mechanisms of neurodegeneration in STXBP1-E patients, but also provides new insights into the pathogenesis of α-synucleinopathies.

The Middle Triassic palaeontomofauna of Monte San Giorgio with the description of Merithone laetitiae (†Permithonidae) gen. et sp. nov.

AbstractThe Triassic is considered a crucial period for the establishment of the modern insect fauna and fossil records from this period are fundamental for understanding the real impact that the end Permian Mass Extinction events had on these animals. Here, we review the insect fossils from one of the main deposits of this period in the world, Monte San Giorgio, which is considered one of the nine main insect Fossillagerstätten. In this Lagerstätte, located on the border between Switzerland and Italy, a total of 273 fossil insects have been collected in five localities. The fossils found in Val Mara site D, one of the two richest insect fossils sites of Monte San Giorgio, present peculiar features, such as extraordinary sizes and phosphatisation of internal tissues revealing fine internal details. In contrast, the Val Mara site VM 12 fossil record (248 specimens) is dominated by small to medium size insects, usually almost intact, preserving details such as setae on wings and compound eyes. Besides these exceptional features, these fossil insects are of extreme evolutionary importance, since they represent the first or the last occurrence for their lineage. In this regard, their use to calibrate nodes in a phylogenomic dating analysis led to backdating the origin of many insect lineages, including Diptera and Heteroptera. Up to now, a total of five species from Monte San Giorgio have been formally described, belonging to the orders Archaeognatha (†Monura and Machilidae), Ephemeroptera, Hemiptera (Tingidae) and Coleoptera (Adephaga). A further species, Merithone laetitiae (†Permithonidae) gen. et sp. nov., whose fossil is included among the recent findings in Val Mara site VM 12, is described in the present work.

Chronic sub-lethal exposure to clothianidin triggers organismal and sub-organismal-level health hazards in a non-target organism, Drosophila melanogaster

Neonicotinoids are among the most widely used systemic pesticides across the world. These chemicals have gathered significant attention for their potential adverse impacts on non-target organisms. Clothianidin is a novel neonicotinoid pesticide, employed globally to control sucking and chewing types of pests. In nature, various non-target organisms can be exposed to this chemical through contaminated food, water, and air. Nonetheless, extensive investigations demonstrating the sub-lethal impacts of clothianidin on non-target entities are limited. Hence, the present study was aimed to unravel the chronic sub-lethal impacts (LC50 0.74 μg/mL) of clothianidin on a non-target organism, Drosophila melanogaster. The study parameters involved multiple tiers of life ranging from organismal level to the sub-cellular level. 1st instar larvae were exposed to the six sub-lethal concentrations viz. 0.05, 0.06, 0.07, 0.08, 0.09, and 0.1 μg/mL of clothianidin till their 3rd larval instar. Investigations involving organismal level have revealed clothianidin-induced significant reduction in the developmental duration, life span, phototaxis, and physical activities of the treated individuals. Interestingly, the tested compound has also altered the compound eye morphology of treated flies. Study was extended to the tissue and cellular levels where reduced cell viability in gut, brain, and fat body was apparent. Additionally, increased ROS production, nuclear disorganization, and higher lipid deposition were evident in gut of exposed individuals. Study was further extended to the sub-cellular level where chronic exposure to clothianidin up-regulated the major oxidative stress markers such as lipid peroxidation, protein carbonylation, HSP-70, SOD, catalase, GSH, and thioredoxin reductase. Furthermore, the activities of detoxifying enzymes such as CYP4501A1 and GST were also altered. Chronic exposure to clothianidin also triggered DNA fragmentation in treated larvae. In essence, results of this multi-level study depict the ROS-mediated toxicity of clothianidin on a non-target organism, D. melanogaster.

Compact biologically inspired camera with computational compound eye

Abstract The growing interests have been witnessed in the evolution and improvement of artificial compound eyes (CE) inspired by arthropods. However, the existing CE cameras are suffering from a defocusing problem due to the incompatibility with commercial CMOS cameras. Inspired by the CEs of South American Shrimps, we report a compact biologically inspired camera that enables wide-field-of-view (FOV), high-resolution imaging and sensitive 3D moving trajectory reconstruction. To overcome the defocusing problem, a deep learning architecture with distance regulation is proposed to achieve wide-range-clear imaging, without any hardware or complex front-end design, which greatly reduces system complexity and size. The architecture is composed of a variant of Unet and Pyramid-multi-scale attention, with designed short, middle and long distance regulation. Compared to the current competitive well-known models, our method is at least 2 dB ahead. Here we describe the high-resolution computational-CE camera with 271 ommatidia, with a weight of 5.4 g an area of 3 × 3 cm2 and 5-mm thickness, which achieves compatibility and integration of CE with commercial CMOS. The experimental result illustrates this computational-CE camera has competitive advantages in enhanced resolution and sensitive 3D live moving trajectory reconstruction. The compact camera has promising applications in nano-optics fields such as medical endoscopy, panoramic imaging and vision robotics.

Biomimetic Multifunctional Graphene-Based Coating for Thermal Management, Solar De-Icing, and Fire Safety: Inspired from the Antireflection Nanostructure of Compound Eyes.

Due to the ubiquitous and inexhaustible solar source, photothermal materials have gained considerable attention for their potential in heating and de-icing. Nevertheless, traditional photothermal materials, exemplified by graphene, frequently encounter challenges emanating from their elevated reflectance. Inspired by ocular structures, this study uses the Fresnel equation to enhance the photo-thermal conversion efficiency of graphene by introducing a polydimethylsiloxane (PDMS)/silicon dioxide (SiO2) coating, which reduces the light reflectance (≈20%) through destructive interference. The designed coating achieves an equilibrium temperature of ≈77°C at one sun and a quick de-icing in ≈65 s, all with a thickness of 5µm. Simulations demonstrate that applying this coating to high-rise buildings results in energy savings of ≈31% in winter heating. Furthermore, the combination of PDMS/SiO2 and graphene confers a notable enhancement in thermal stability through a synergistic flame-retardant mechanism, effectively safeguarding polyurethane against high temperatures and conflagrations, leading to marked reduction of 58% and 28% in heat release rate and total heat release. This innovative design enhances the photo-thermal conversion, de-icing function, and flame retardancy of graphene, thereby advancing its applications in outdoor equipment, high-rise buildings, and aerospace vessels.

Scientific analysis of two compound eye beads unearthed in Hejia Village, Zhouling

The glass compound eye bead is the exquisite embodiment of the glassmaking technology of ancient craftsmen, and is an example of the cultural exchange between China and the West during the Warring States Period. This study takes two dots and mesh beads with seriously weathered surfaces excavated from Hejia village, Zhouling as the research object. Micromorphology, X-ray fluorescence spectroscopy (XRF), microscopic laser Raman spectroscopy and X-ray photoelectron spectroscopy (XPS) were respectively used to determine the chemical elements, valence states and compositions of the glass matrix and its weathering products. In this study, the valence state analysis of group-d elements is used to reveal the electron transition mode and explain the colour formation reason of blue-black glass matrix. In terms of weathering products, in addition to the identification of common cerusite [PbCO3] and barite [BaSO4], the study also found the blue weathering product alforsite [Ba5(PO4)3Cl] for the first time. The study also makes reasonable assumptions about the reasons for their appearance. The X-ray photoelectron spectroscopy (XPS) used in this study has positive significance for the study of the formation mechanism of glass colour. The scientific and technological analysis data of these two glass beads provide basic data for the related research of the lead-barium glass system produced in China, and also provide a certain scientific basis for the related protection research.

Looking across the gap: Understanding the evolution of eyes and vision among insects.

The compound eyes of insects exhibit stunning variation in size, structure, and function, which has allowed these animals to use their vision to adapt to a huge range of different environments and lifestyles, and evolve complex behaviors. Much of our knowledge of eye development has been learned from Drosophila, while visual adaptations and behaviors are often more striking and better understood from studies of other insects. However, recent studies in Drosophila and other insects, including bees, beetles, and butterflies, have begun to address this gap by revealing the genetic and developmental bases of differences in eye morphology and key new aspects of compound eye structure and function. Furthermore, technical advances have facilitated the generation of high-resolution connectomic data from different insect species that enhances our understanding of visual information processing, and the impact of changes in these processes on the evolution of vision and behavior. Here, we review these recent breakthroughs and propose that future integrated research from the development to function of visual systems within and among insect species represents a great opportunity to understand the remarkable diversification of insect eyes and vision.