Beetle Hind Wing Research Articles

Investigating the Mechanical Performance of Bionic Wings Based on the Flapping Kinematics of Beetle Hindwings.

The beetle, of the order Coleoptera, possesses outstanding flight capabilities. After completing flight, they can fold their hindwings under the elytra and swiftly unfold them again when they take off. This sophisticated hindwing structure is a result of biological evolution, showcasing the strong environmental adaptability of this species. The beetle's hindwings can provide biomimetic inspiration for the design of flapping-wing micro air vehicles (FWMAVs). In this study, the Asian ladybird (Harmonia axyridis Pallas) was chosen as the bionic research object. Various kinematic parameters of its flapping flight were analyzed, including the flight characteristics of the hindwings, wing tip motion trajectories, and aerodynamic characteristics. Based on these results, a flapping kinematic model of the Asian ladybird was established. Then, three bionic deployable wing models were designed and their structural mechanical properties were analyzed. The results show that the structure of wing vein bars determined the mechanical properties of the bionic wing. This study can provide a theoretical basis and technical reference for further bionic wing design.

Structural response and mechanical properties of the hind wing of the beetle Protaetia brevitarsis.

The folding/unfolding mechanism and collision recovery effect of the beetle's hind wings can provide biomimetic inspiration for the optimization of wing deplorability and the investigation of collision prevention recovery mechanism of new amphibious morphing vehicle. In this study, a method is described to investigate the structural response and mechanical properties of the hind wings of the beetle Protetia brevitarsis under natural conditions. The specially processed test samples were conducted to tensile testing, which facilitates the evaluation of the mechanical properties of specific areas of the hind wing. The micro geometric morphological characteristics of the cross-section of the specimen after tensile fracture were observed by scanning electron microscopy. The three-dimensional morphology of the ventral and dorsal sides of the hind wing was characterized using three-dimensional scanning and reverse modeling methods. The finite element model of the hind wing is developed to investigate the structural deformation and modal response characteristics of its flapping. The uniformly distributed load on the hind wing surface is derived from the lift characteristics obtained from the computational fluid dynamics simulation of flapping wing motion. RESEARCH HIGHLIGHTS: Scanning electron microscope is used to observe the cross-sectional characteristics of the veins and membranes. The material properties of the wing membranes and veins of the hind wings were measured using the tensile testing system. The three-dimensional morphology of the hind wing was characterized using 3D scanning and reverse modeling methods. The finite element model of the hind wing is developed to investigate the structural deformation and modal response characteristics of its flapping.

A study on the aerodynamic behaviors learned from microscopy imaging of beetle corrugated hindwing.

Beetle hindwings have the unique advantages of lightweight and high strength, which play a key role in flight. In this study, the beetle hindwings were cut along the chordal direction, then the first groove microstructure of different vein cross sections was investigated using the 3D microscope system and the laser scanning confocal microscope. It was found that the position of the first groove relative to the entire chordal cross section of the wing gradually moves backward, which has an effect on the flying aerodynamic behaviors of the beetle. Next, three corrugated airfoils learned from the microscopy imaging of the ladybird beetle hindwing were designed. Then, aerodynamic behaviors were calculated by the ANSYS Fluent software, and it was confirmed that the position of the first groove microstructure affects the aerodynamic performance of the airfoil. For further study, the influence of corrugated structural and motion parameters on the aerodynamic, 2D 'simplified' airfoil models with triangular wave airfoil models (TWA models) was developed and studied. RESEARCH HIGHLIGHTS: The position of the first groove microstructure affects the aerodynamic performance of the airfoil. The pressure difference of different corrugation patterns shows significantly asymmetric during the upstroke and downstroke. The aerodynamic is optimal of 2D-TWA models, when the number of corrugations is five, the corrugation is right angle, and the flapping frequency is 75 Hz.

Scarab Beetle‐Inspired Embodied‐Energy Membranous‐Wing Robot with Flapping‐Collision Piezo‐Mechanoreception and Mobile Environmental Monitoring

AbstractThe mechanoreception system in bionic micro air vehicles, akin to insect sensory neurons, handles internal and external stimulus information. However, current onboard mechanoreception methods add weight and necessitate additional power. Employing the embodied energy design paradigm, a lightweight intelligent membranous wing is proposed, mimicking the scarab beetle's hindwing morphology and kinematics. This wing serves multiple functions, including aerodynamic load‐bearing, flight piezo‐mechanoreception, and power supply. The beetle's semi‐tubular costa structure is replicated, featuring a compliant leading edge for upstroke aerodynamic load resistance. Inspired by beetle hindwing veins and membranes, the bionic wing with three membranous fields: anal, medial, and apical, using heat lamination of multilayer materials is fabricated. The bionic wing's aerodynamic performance closely mirrors that of a real beetle hindwing, enabling various flight maneuvers and validating its real‐flight potential. As a piezo‐mechanoreception receptor for micro air vehicles, the bionic intelligent wing senses flapping frequency, wing deformations, and collisions through voltage signals from piezoelectric materials in the three membranous fields. Energy harvested from flapping‐wing motion powers onboard light intensity and ultraviolet sensors for mobile 3D environmental monitoring. This integration of aerodynamics, mechanoreception, and power supply via embodied flapping energy offers a novel approach for designing future intelligent flapping‐wing micro air vehicles.

Detection of Hindwing Landmarks Using Transfer Learning and High-Resolution Networks.

Hindwing venation is one of the most important morphological features for the functional and evolutionary analysis of beetles, as it is one of the key features used for the analysis of beetle flight performance and the design of beetle-like flapping wing micro aerial vehicles. However, manual landmark annotation for hindwing morphological analysis is a time-consuming process hindering the development of wing morphology research. In this paper, we present a novel approach for the detection of landmarks on the hindwings of leaf beetles (Coleoptera, Chrysomelidae) using a limited number of samples. The proposed method entails the transfer of a pre-existing model, trained on a large natural image dataset, to the specific domain of leaf beetle hindwings. This is achieved by using a deep high-resolution network as the backbone. The low-stage network parameters are frozen, while the high-stage parameters are re-trained to construct a leaf beetle hindwing landmark detection model. A leaf beetle hindwing landmark dataset was constructed, and the network was trained on varying numbers of randomly selected hindwing samples. The results demonstrate that the average detection normalized mean error for specific landmarks of leaf beetle hindwings (100 samples) remains below 0.02 and only reached 0.045 when using a mere three samples for training. Comparative analyses reveal that the proposed approach out-performs a prevalently used method (i.e., a deep residual network). This study showcases the practicability of employing natural images-specifically, those in ImageNet-for the purpose of pre-training leaf beetle hindwing landmark detection models in particular, providing a promising approach for insect wing venation digitization.

Design optimization and wind tunnel investigation of a flapping system based on the flapping wing trajectories of a beetle's hindwings

To design a flapping-wing micro air vehicle (FWMAV), the hovering flight action of a beetle species (Protaetia brevitarsis) was captured, and various parameters, such as the hindwing flapping frequency, flapping amplitude, angle of attack, rotation angle, and stroke plane angle, were obtained. The wing tip trajectories of the hindwings were recorded and analyzed, and the flapping kinematics were assessed. Based on the wing tip trajectory functions, bioinspired wings and a linkage mechanism flapping system were designed. The critical parameters for the aerodynamic characteristics were investigated and optimized by means of wind tunnel tests, and the artificial flapping system with the best wing parameters was compared with the natural beetle. This work provides insight into how natural flyers execute flight by experimentally duplicating beetle hindwing kinematics and paves the way for the future development of beetle-mimicking FWMAVs.

Insect wing 3D printing

Insects have acquired various types of wings over their course of evolution and have become the most successful terrestrial animals. Consequently, the essence of their excellent environmental adaptability and locomotive ability should be clarified; a simple and versatile method to artificially reproduce the complex structure and various functions of these innumerable types of wings is necessary. This study presents a simple integral forming method for an insect-wing-type composite structure by 3D printing wing frames directly onto thin films. The artificial venation generation algorithm based on the centroidal Voronoi diagram, which can be observed in the wings of dragonflies, was used to design the complex mechanical properties of artificial wings. Furthermore, we implemented two representative functions found in actual insect wings: folding and coupling. The proposed crease pattern design software developed based on a beetle hindwing enables the 3D printing of foldable wings of any shape. In coupling-type wings, the forewing and hindwing are connected to form a single large wing during flight; these wings can be stored compactly by disconnecting and stacking them like cicada wings.

Wing shape optimization design inspired by beetle hindwings in wind tunnel experiments

Flighted beetles have deployable hindwings, which enable them to directly reduce their body size, and thus are excellent bioinspired prototypes for microair vehicles (MAVs). The wing shape of MAVs has an important influence on their aerodynamics. In this paper, wing shapes, inspired from three beetle species’ hindwings and designed in terms of the wing camber angle, geometry (including wing length, aspect ratio (AR), and taper ratio (TR)) and wing area, were selected and varied to optimize lift together with the efficiency of wing. All the wings were fabricated by a Tyvek membrane and tested in a wind tunnel. The camber angle and AR were found to have a critical role in force production. The best performance was obtained by a wing with a camber angle of 10°, wing length of 125 mm, AR of 7.06, TR of 0.40 and wing area of 4115 mm2.

Combined effects of wrinkled vein structures and nanomechanical properties on hind wing deformation

The veins in the hind wings of the Asian ladybird beetle (Harmonia axyridis) play active roles in flight and in the folding/unfolding of the hind wing. Wrinkled vein structures are located within the bending zone and are used for folding the hind wing. This paper investigates the coupled effect of wrinkled vein structures within the hind wing of H. axyridis on its deformation. Based on the nanomechanical properties of the veins, morphology of the hind wing, surface structures of the veins, and microstructures of the cross sections (including the veins and wing membranes), four 3-D coupling models (Model I and Model II: variably reduced-modulus veins with and without wrinkles, respectively; Model III and Model IV: uniformly reduced-modulus veins with and without wrinkles, respectively) are established. Relative to the bending and twisting model shapes, Model I has much more flexibility during passive deformation to control wing deformations. The simulation results show that both the wrinkled structures in the bending zone and the variably reduced modulus of the veins contribute to the flight performance (the bending and twisting deformations) of the hind wings, which has important implications for the design of the deployable wings of micro air vehicles (MAVs).

Asian ladybird folding and unfolding of hind wing: biomechanical properties of resilin in affecting the tensile strength of the folding area

The deployable hind wings of Coleoptera are a highly specialized motive system that can fold and unfold in a unique way. Resilin in the wing membrane of Asian ladybird beetle (Harmonia axyridis) hind wings plays an active role during folding and unfolding of the wing. This study investigates the tensile properties of the hind wing and the distribution of resilin through the hind wing in an adult H. axyridis (Coleoptera: Coccinellidae) and how the resilin in the membrane of the hind wing affects its mechanical characteristics. The cross sections of veins of the hind wing are investigated by inverted fluorescence microscopy. Based on those results, two three-dimensional finite element models of the hind wing with/without resilin are established. The displacements, when subjected to pressure on the ventral side, are analyzed when the membrane wings are filled with/without resilin. The resilin in the hind wing is effectively for changing the flight performance such as the condition of stress and deformation. The results in this paper reveal the multiple functions of the resilin in the hind wings and have important implications for the design of biomimetic deployable micro-air vehicles.

Effect of microtrichia on the interlocking mechanism in the Asian ladybeetle, Harmonia axyridis (Coleoptera: Coccinellidae).

The hindwings of beetles are folded under the elytra when they are at rest but are extended during flight, which can provide bioinspiration for the design of deployable micro air vehicles (MAVs). Beetle hindwings must be able to be both securely locked under the elytra and freely extended for flight, depending on the required action. To investigate the locking mechanism, this study used environmental scanning electron microscopy (ESEM) to examine the microstructures of the elytra, hindwings and abdomen of the Asian ladybeetle, Harmonia axyridis (Pallas, 1773). On the ventral side (VS) of the elytra, the microtrichia show a transitional structure from the lateral edge to the medial edge. On the hindwing surface, the folded regions were observed on both the dorsal side (DS) and the VS. On the abdomen, the microtrichia between the abdominal segments show a cyclical change from sparse to dense in each segment in the middle of the abdomen. Furthermore, the different directions of microtrichia that lead to self-locking friction on the surfaces of the hindwing, elytron and abdomen appear to facilitate interlocking. A model for the interlocking of the hindwings of the H. axyridis was established, and its underlying mechanism is discussed.

Elytra reduction may affect the evolution of beetle hind wings

Beetles are one of the largest and most diverse groups of animals in the world. Conversion of forewings into hardened shields is perceived as a key adaptation that has greatly supported the evolutionary success of this taxa. Beetle elytra play an essential role: they minimize the influence of unfavorable external factors and protect insects against predators. Therefore, it is particularly interesting why some beetles have reduced their shields. This rare phenomenon is called brachelytry and its evolution and implications remain largely unexplored. In this paper, we focused on rare group of brachelytrous beetles with exposed hind wings. We have investigated whether the elytra loss in different beetle taxa is accompanied with the hind wing shape modification, and whether these changes are similar among unrelated beetle taxa. We found that hind wings shape differ markedly between related brachelytrous and macroelytrous beetles. Moreover, we revealed that modifications of hind wings have followed similar patterns and resulted in homoplasy in this trait among some unrelated groups of wing-exposed brachelytrous beetles. Our results suggest that elytra reduction may affect the evolution of beetle hind wings.

A Simulation of the Flight Characteristics of the Deployable Hindwings of Beetle

An insect is an excellent biological object for the bio-inspirations to design and develop a MAV. This paper presents the simulation study of the flight characteristics of the deployable hindwings of beetle, Dorcustitanus platymelus. A 3D geometric model of the beetle was obtained using a 3D laser scanning technique. By studying its hindwings and flight mechanism, the mathematical model of the flapping motion of its hindwings was analyzed. Then a simulation analysis was carried out to analyze and evaluate the flapping flying aerodynamic characteristics. After that, the flow of blood in the hindwing veins was studied through simulation to determine the maximum pressure on a vein surface and the minimum blood flow in flight. A number of interesting bio-inspirations were obtained. It is believed that these findings can be used for the design and development of a MAV with similar flying capabilities to a natural beetle.

The hydraulic mechanism in the hind wing veins of Cybister japonicus Sharp (order: Coleoptera).

The diving beetles (Dytiscidae, Coleoptera) are families of water beetles. When they see light, they fly to the light source directly from the water. Their hind wings are thin and fragile under the protection of their elytra (forewings). When the beetle is at rest the hind wings are folded over the abdomen of the beetle and when in flight they unfold to provide the necessary aerodynamic forces. In this paper, the unfolding process of the hind wing of Cybister japonicus Sharp (order: Coleoptera) was investigated. The motion characteristics of the blood in the veins of the structure system show that the veins have microfluidic control over the hydraulic mechanism of the unfolding process. A model is established, and the hind wing extending process is simulated. The blood flow and pressure changes are discussed. The driving mechanism for hydraulic control of the folding and unfolding actions of beetle hind wings is put forward. This can assist the design of new deployable micro air vehicles and bioinspired deployable systems.

Fluid analysis of vein of beetle hindwing during unfolding action

Beetles demonstrate excellent flight performance, and their various flight skills predominantly depend on the ingenious structure of the wing membrane. The wings of insects have been optimized in structure, function and material through millions of years of evolution. The hindwings of most beetles are thin and fragile; when at rest, they are held over the back of the beetle. From drawings, it is clear that the biological wing structure of beetles could be exploited for the efficient flight of Micro Air Vehicles (MAVs). This paper strives to reveal the hydraulic mechanism at work during the hindwing unfolding process through the use of the finite element method in FLUENT. The inlet pressure was set to be similar to the folded point pressure, and the flow pattern was treated as similar to a one-way flow. We anticipate that our work will serve as the basis of further sophisticated research on the folding/unfolding mechanisms of beetle hindwings, which may provide design insights for portable MAVs with morphing wings and guide the development of bioinspired deployable systems.

Coptoclavid beetles (Insecta: Coleoptera: Adephaga) from the Triassic of Lower Franconia, Germany

Many fossils of water beetles of the family Coptoclavidae have been found unexpectedly among insect fossils from the Middle Triassic (Anisian) and Upper Triassic of Franconia, Germany. Very small (about 3 mm long) beetles with longitudinal dark stripes on the elytra, similar in coloration pattern to beetles of the genus Holcoptera Handlirsch, 1906 from the terminal Triassic and Lower Jurassic of England and Lower Jurassic of the United States, have been found in Anisian deposits. Similar but larger beetles (about 5 mm long) have been found in Keuper (Carnian) deposits, in which they occur much more frequently than in Anisian localities, even dominating some of these localities. Unfolded or fragmentary hindwings that also belong to beetles of the same species and match the elytra in size have also been found. There are no known localities in which so many beetle hindwings occur, especially hindwings of the same species. They are described here as wings of Coptoclavidae. A small incomplete larva matching these beetles in size has also been found. The beetles are described as representatives of a new genus of the subfamily Coptoclaviscinae. In addition to them, the larvae of a rather large coptoclavid Protonectes Prokin et Ponomarenko, 2013 was described earlier from the same deposits; it is assigned here to the subfamily Timarchopsinae. Only two elytra with numerous fine grooves not bearing any punctures match this larva in the available collection. Similar elytra were described earlier from the Jurassic of Europe and Siberia as Dinoharpalus Handlirsch, 1906. A small elytron with many grooves was described in the same genus from the terminal Permian of Eastern Europe. Similar elytra are known in coptoclavids described from the Lower Cretaceous of Spain as Hispaniclavina. The presence of such advanced beetles as coptoclavids as early as the Lower Anisian shown that the famous Permian–Triassic crisis was not so deep as it is usually believed, and many beetles survived it, disappearing, however, from the fossil record in the Early Triassic. Keywords: insects, beetles, Triassic

Design and Demonstration of Insect Mimicking Foldable Artificial Wing Using Four-Bar Linkage Systems

In this work, we develop an artificial foldable wing that mimics the hind wing of a beetle (Allomyrina dichotoma). In real flight, the beetle unfolds forewings and hind wings, and maintains the unfolded configuration unless it is exhausted. The artificial wing has to be able to maintain a fully unfolded configuration while flapping at a desirable flapping frequency. The artificial foldable hind wing developed in this work is based on two four-bar linkages which adapt the behaviors of the beetle's hind wing. The four-bar-linkages are designed to mimic rotational motion of the wing base and the vein folding/unfolding motion of the beetle's hind wing. The behavior of the artificial wings, which are installed in a flapping-wing system, is observed using a high-speed camera. The observation shows that the wing could maintain a fully unfolded configuration during flapping motion. A series of thrust measurements are also conducted to estimate the force generated by the flapping-wing system with foldable artificial wings. Although the artificial foldable wings give added burden to the flapping-wing system because of its weight, the thrust measurement results show that the flapping-wing system could still generate reasonable thrust.

Structural Characteristics of Allomyrina Dichotoma Beetle's Hind Wings for Flapping Wing Micro Air Vehicle

AbstractIn this study, we present a complete structural analysis of Allomyrina dichotoma beetle's hind wings by investigating their static and dynamic characteristics. The wing was subjected to the static loading to determine its overall flexural stiffness. Dynamic characteristics such as natural frequency, mode shape, and damping ratio of vibration modes in the operating frequency range were determined using a Bruel & Kjaer fast Fourier transform analyzer along with a laser sensor. The static and dynamic characteristics of natural Allomyrina dichotoma beetle's hind wings were compared to those of a fabricated artificial wing. The results indicate that natural frequencies of the natural wing were significantly correlated to the wing surface area density that was defined as the wing mass divided by the hind wing surface area. Moreover, the bending behaviors of the natural wing and artificial wing were similar to that of a cantilever beam. Furthermore, the flexural stiffness of the artificial wing was a little higher than that of the natural one whereas the natural frequency of the natural wing was close to that of the artificial wing. These results provide important information for the biomimetic design of insect-scale artificial wings, with which highly maneuverable and efficient micro air vehicles can be designed.

2G44 甲虫様後翅モデルによる折り畳み/展開動作時の力伝達様式の解明(OS1-2:自然界のバイオメカニクス・バイオミメティクス(2))

2G44 甲虫様後翅モデルによる折り畳み/展開動作時の力伝達様式の解明(OS1-2:自然界のバイオメカニクス・バイオミメティクス(2))

Biomechanical Properties of Insect Wings: The Stress Stiffening Effects on the Asymmetric Bending of the Allomyrina dichotoma Beetle's Hind Wing

Although the asymmetry in the upward and downward bending of insect wings is well known, the structural origin of this asymmetry is not yet clearly understood. Some researchers have suggested that based on experimental results, the bending asymmetry of insect wings appears to be a consequence of the camber inherent in the wings. Although an experimental approach can reveal this phenomenon, another method is required to reveal the underlying theory behind the experimental results. The finite element method (FEM) is a powerful tool for evaluating experimental measurements and is useful for studying the bending asymmetry of insect wings. Therefore, in this study, the asymmetric bending of the Allomyrina dichotoma beetle's hind wing was investigated through FEM analyses rather than through an experimental approach. The results demonstrated that both the stressed stiffening of the membrane and the camber of the wing affect the bending asymmetry of insect wings. In particular, the chordwise camber increased the rigidity of the wing when a load was applied to the ventral side, while the spanwise camber increased the rigidity of the wing when a load was applied to the dorsal side. These results provide an appropriate explanation of the mechanical behavior of cambered insect wings, including the bending asymmetry behavior, and suggest an appropriate approach for analyzing the structural behavior of insect wings.