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Not only does the Dynastes tityus beetle display a reversible color change controlled by differences in humidity, but also, the elytron scale can change color from yellow-green to deep-brown in specified shapes. The results obtained by focused ion beam-scanning electron microscopy (FIB-SEM), show that the epicuticle (EPI) is a permeable layer, and the exocuticle (EXO) is a three-dimensional photonic crystal. To investigate the mechanism of the reversible color change, experiments were conducted to determine the water contact angle, surface chemical composition, and optical reflectance, and the reflective spectrum was simulated. The water on the surface began to permeate into the elytron via the surface elemental composition and channels in the EPI. A structural unit (SU) in the EXO allows local color changes in varied shapes. The reflectance of both yellow-green and deep-brown elytra increases as the incidence angle increases from 0° to 60°. The microstructure and changes in the refractive index are the main factors that influence the process of reversible color change. According to the simulation, the lower reflectance causing the color change to deep-brown results from water infiltration, which increases light absorption. Meanwhile, the waxy layer has no effect on the reflection of light. This study lays the foundation to manufacture engineered photonic materials that undergo controllable changes in iridescent color.

Dynastes tityus (D. tityus) is a typical beetle whose elytra are light and strong. The primary function of elytra is to protect beetle’s\ud hindwings. In this paper, D. tityus elytra were selected as the biological prototype for the investigation to obtain bio-inspirations for the\ud design and development of light materials with high ratio of strength to mass. Firstly, the microstructure investigation and quasi-static\ud nanoindentation tests have been carried out on the ten samples of the selected elytra of D. tityus to reveal their mechanical properties and\ud microstructures. Secondly, based on the findings from the microstructure investigation and nanoindentation tests, three models of\ud bio-inspired materials have been proposed for further study to gain the deep understanding of the relationships between the special mechanical\ud characteristics and microstructures. Then Finite Element Analysis (FEA) simulations have been performed on the three models\ud for harvesting the bio-inspirations for the initial design of light materials. Finally, through comparative analysis of the findings from the\ud microstructure investigation, the nanoindentation tests and the simulations, some meaningful bio-inspirations have been reaped for the\ud future optimization of the design and development of light materials with high ratio of strength to mass.

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).

The deployable hind wings of the Asian ladybird beetle (Harmonia axyridis) play important roles in their flight. Wrinkle structures of veins are found on the bending zones of the hind wings ofH. axyridis. This paper investigates the effect of the wrinkle structures of the veins of the hind wing on its deformation. Based on the nanomechanical properties of the veins, morphology of the hind wing, surface structures of veins and microstructures of the cross sections, including the veins and wing membranes, we establish four three-dimensional coupling models for hind wings with/without wrinkles with different and uniform reduced modulus. Relative to the bending and twisting model shapes, Model I, which includes the wrinkle structure and different reduced-modulus veins, has much more flexibility of passive deformation to control wing deformations. The results show that both the wrinkle structures in the bending zone and varying reduced modulus of the veins contribute to the flight performance of bending and twisting deformations of the hind wings, which have important implications for the bionic design of the biomimetic deployable wing of micro air vehicles (MAVs).

The folding/unfolding hind wings of Asian ladybird beetle (Harmonia axyridis) show remarkable flight performance and the veins of hind wings have a significant influence on its flight performance. The structure morphologies of the veins of H. axyridis hind wing are investigated to obtain the thickness of wing membrane and the diameter of veins for the design of three-dimensional (3-D) model. Additionally, considering the hollow veins of hind wing observed by scanning electron microscopy (SEM), mechanical properties of hind wing for H. axyridis flight are researched. The static analysis results shown that the variation tendency of the total deformation of the hind wing are almost relationship with −60°, −30°, 0°, 30° and 60° of attack angles and the locations of the pressure setting. The total deformation of H. axyridis hind wings during flight in different attack angles influenced will be helpful to design the flight performance of biomimetic micro air vehicles (MAVs).

Beetle cuticles are light weight with high strength, and some beetles are able to change its coloration during the process of growing. In this study, the relationship between nanomechanical properties and microstructures of elytra of irreversibly color-changing Sagra femorata purpurea lichtenstein were investigated, and the bionic architectures based on its elytron which are light weight with high strength were designed for mechanical simulation. The surface morphology of elytron was obtained by confocal laser scanning microscopy (CLSM). The interior microstructures of beetle elytra were stained and then observed by high power microscope used in medical science. Nanomechanical properties of transverse and longitudinal sections of beetle elytra were investigated through nanoindentation tests. Then finite element analysis was used to illustrate the difference of mechanical properties between these two kinds of models with different microstructures on the surface that undergo irreversible color-changing. The elytron of S. lichtenstein not only plays irreversible color-changing by surface morphology but also performs high strength with light weight interior microstructure. This work will lay the foundation for designing new component materials with bionic structures and color-changing ability.

The dragonfly has excellent flying capacity and its wings are typical 2-dimensional composite materials in micro-scale or nano-scale. The nanomechanical behavior of dragonfly membranous wings was investigated with a nanoindenter. It was shown that the maxima of the reduced modulus and nanohardness of the in-vivo and fresh dragonfly wings are about at position of 0.7L, where L is the wing length. It was found that the reduced modulus and nanohardness of radius of the wings of dragonfly are large. The reduced modulus and nanohardness of Costa, Radius and Postal veins of the in-vivo dragonfly wings are larger than those of the fresh ones. The deformation, stress and strain under the uniform load were analyzed with finite element simulation software ANSYS. The deformation is little and the distribution trend of the strain is probably in agreement with that of the stress. It is shown that the main veins have better stabilities and load-bearing capacities. The understanding of dragonfly wings’ nanomechanical properties would provide some references for improving some properties of 2-dimentional composite materials through the biomimetic designs. The realization of nanomechanical properties of dragonfly wings will provide inspirations for designing some new structures and materials of mechanical parts.

The Asian ladybeetle (Harmonia axyridis) is a high-mobility insect which provides inspirations for Micro-aircraft applications. In this study, the hindwings were cut transversely along the curvature change, then the microstructure of leading main vein was investigated. It was found that the thickness of dorsal side (DS) and ventral side (VS) are different, which has an effect on the flying mechanical behaviors of the beetle. Next, the reduced modulus (Er) and hardness (H) of DS and VS were investigated along the veins varying from the base to the region of the principal transverse fold by using a nanoindenter. Then torque was calculated using ANSYS software and it was confirmed that the vein structure of the hindwing has a relationship to its wind-resistant performance. For further study of the wind resistance performance, two single vein structural models were developed and studied.

Micro/nano capsules embedment was an effective method to repair micro crack and mechanical damage. In this paper, preparation technology of self-healing micro-nano capsule based on calcium alginate was studied by in-situ method. And the rate of covering and particle size were investigated under different emulsifier dosages and core-wall ratios.

The hindwings are thin and fragile. However, they can display countless folding/unfolding actions during their lifetime. At the root of the Asian ladybeetle (Harmonia axyridis) hindwings, three thicker veins spread out. In this study, laser scanning confocal microscope (LSCM) was used to acquire the cross-section microstructures of the three thinker main veins. And it was found that the thickness of dorsal side (DS) and ventral side (VS) are different. The irregularly shaped vein chambers are observed from the cross-section microstructure of the three veins. Then the reduced modulus (Er) and hardness (H) of DS and VS were investigated along the veins varying from wing base to the region of principal transverse fold by nanoindentation. All the Er and H appear a tendency of linear increasing. In the folding region, the Er and H of DS were larger than that of VS. The results will be useful to the design of new deployable MAV and bioinspired systems.

This study details an investigation of the viscoelastic behavior of some biomaterials (nacre, cattle horn and beetle cuticle) at lamellar length scales using quasi-static and dynamic nanoindentation techniques in the materials’ Transverse Direction (TD) and Longitudinal Direction (LD). Our results show that nacre exhibits high fracture toughness moving towards a larger campaniform as the stress frequency varies from 10 Hz to 200 Hz. Elytra cuticle exhibits the least fracture toughness presenting little energy dissipation in TD. It was initially speculated that the fracture toughness of the subject materials would be directly related to energy-dissipating mechanisms (mechanical hysteresis), but not the maximum value of the loss tangent tand. However, it was found that the materials’ elastic modulus and hardness are similar in both the TD and LD when assessed using the quasi-static nanoindentation method, but not dynamic nanoindentation. It is believed that the reported results can be useful in the design of new crack arrest and damping materials based on biological counterparts.

Bovine horns are durable that they can withstand an extreme loading force which with special structures and mechanical properties. In this study, the authors apply quasi‐static nanoindentation and modulus mapping techniques to research the nanomechanical properties of bovine horn in the transverse direction (TD) and longitudinal direction (LD). In quasi‐static nanoindentation, the horn's modulus and hardness in the inner layer and the outer layer demonstrated a gradual increase in both TD and LD. Laser scanning confocal microscopy revealed microstructure in the horn with wavy morphology in the TD cross‐section and laminate in the LD cross‐section. When using tensile tests or quasi‐static nanoindentation tests alone, the anisotropy of the mechanical properties of bovine horn were not obvious. However, when using modulus mapping, storage modulus (E ′), loss modulus (E ″) and loss ratio (tan δ) are clearly different depending on the position in the TD and LD. Modulus mapping is proposed as accurately describing the internal structures of bovine horn and helpful in understanding the horn's energy‐absorption, stiffness and strength that resists forces during fighting.

Special internal structures of the cuticle of a beetle have multifunctionality including self-protection and attraction of mates using structural coloration, and being lightweight with high strength, which can protect the body and membranous hindwings. Special optical properties were found in the black spots region (BSR) of the cuticle of the multicolored Asian lady beetle (Harmonia axyridis). Both the BSR and the orange region (OR) have alternating layers of chitin and melanoprotein, as detected using field emission scanning electron microscopy (FESEM). However, a parallel wavy line structure was found in the BSR via laser scanning confocal microscopy (LSCM). This special structural color may arise via a diffraction grating mechanism. To explore the relationship between the material and its optical properties, the dynamic nanoindentation approach (nano-DMA) was used. The viscoelastic properties of the cuticle were assessed including the storage modulus (E′), loss modulus (E′′) and loss tangent (tan δ), in the differently colored zones. The extent of protein cross-linking affects the cuticle's mechanical properties. We then demonstrated the applicability of a power-law frequency dependence analysis of E′ and tan δ. Furthermore, the frequency exponent of n and tan δ were discussed in relation to the BSR and OR. A lower wavelength of maximum reflectance was found in the BSR that had little frequency dependence on n and a larger tan δ value related to its extent of protein cross-linking. This is contrary to the results obtained in the OR. The results will help in designing lightweight, high strength, and color-changing micro air vehicles (MAVs).

ABSTACT With the rapid development of bionic science, especially the progress that has been made in the fields of biomaterials and biomimetics, there is now great interest in the surface and internal mechanical properties of biological materials at the micro- and nanoscale. The study of micro- and nanoscale biomaterial mechanical properties could enable interdisciplinary applications in materials science, biological science and bionic science. Dung beetle (Copris ochus Motschulsky) cuticle is a viscoelastic material that is both viscous and flexible via elastic deformation under external forces; where stress σ, strain ϵ and elastic modulus E are related in the following way: σ = Eϵ. In addition, as σ is related to the rate of strain, time is also a factor. The stress-strain relationships of various parts of dung beetle cuticle were investigated in this paper. As time increased, the stress and strain of the material were found to decrease and increase, respectively, indicating that when the material was indented for a certain period, the interaction force between the indenter and the material gradually achieved a state of dynamic equilibrium. However, strain continued to occur until reaching a point of equilibrium because of the creep phenomenon. The stress-strain curves showed a strong character in each holding time condition: the longer the holding time, the more flattened the stress-strain curve. These findings will be useful in the advanced design of strong, lightweight, and biomimetic composites.

The effects of biomimetic designs of tine furrow opener surface on equivalent pressure and pressure in the direction of motion on opener surface against soil were studied by finite element method (FEM) simulation and the effects of these designs on tool force and power requirements were examined experimentally. Geometrical structures of the cuticle surfaces of dung beetle (Copris ochus Motschulsky) were examined by stereoscopy. The structures of the cuticle surfaces and Ultra High Molecular Weight Polyethylene (UHMWPE) material were modeled on surface of tine furrow opener as biomimetic designs. Seven furrow openers were analyzed in ANSYS program (a FEM simulation software). The biomimetic furrow opener surfaces with UHMWPE structures were found to have lower equivalent pressure and pressure in the direction of motion as compared to the conventional surface and to the biomimetic surfaces with textured steel-35 structures. It was found that the tool force and power were increased with the cutting depth and operating speed and the biomimetic furrow opener with UHMWPE tubular section ridges showed the lowest resistance and power requirement against soil.

The surface materials and structures of insect cuticle can provide useful information for designing anti-adhesion components material. Quantitative measurement of mechanical properties of insect cuticle will help to develop biomimetic materials suitable for industrial products. In this work, the mechanical properties, such as the reduced modulus and hardness in nano-scale, of the cuticle of beetle Geotrupes stercorarius Linnaeus, Copris ochus Motschulsky and Holotrichia sichotana Brenske, were investigated by using a nanoindenter. It was found that the reduce modulus and hardness of these three beetles are different. The main cause of the difference of the mechanical properties is probably due to their different living circumstance, lifestyle and different functions of segments.

The fracture toughness of hard biomaterials, such as nacre, bovine hoof wall and beetle cuticle, is associated with fibrous or lamellar structures that deflect or stop growing cracks. Their hardness and reduced modulus were measured by using a nanoindenter in this paper. Micro/nanoscale cracks were generated by nanoindentation using a Berkovich tip. Nanoindentation of nacre and bovine hoof wall resulted in pile-up around the indent. It was found that the fracture toughness (K C ) of bovine hoof wall is the maximum, the second is nacre, and the elytra cuticle of dung beetle is the least one.

The special structural and mechanical characteristics of beetle elytral cuticle will be instructive in bionic for designing composites materials. Because the microscale or nanoscale thickness of the beetle cuticle, it was difficult to determine the cuticle's mechanical characteristics until nanoindentation techniques were developed. The nanomechanical characteristics (reduced modulus Er and hardness H) of dung beetle Copris ochus Motschulsky cuticle were investigated by nanoindenter. To understand water's effect, samples were tested immediately or after different amounts of time. The nanoindentation results showed that the mechanical characteristics were strongly influenced by sample aging and that Er and H increased with a decrease in water content. The results were discussed in following about relationship of the mechanical characteristics of the cuticle and its behaviors.

Some tribological behavior between mature Gampsocleis gratiosa foot pads and vertical flats of different materials were studied in this work. stereomicroscope (SMS) and scanning electron microscope (SEM) were used to measure the morphology of the Gampsocleis gratiosa foot pads. An atomic force microscope (AFM) was used to measure the morphologies of the surfaces of glass and a wall doped with calcium carbonate material. The attaching behavior of Gampsocleis gratiosa feet on the two vertical surfaces was observed. The attaching force (perpendicular to the vertical surface) and the static frictional force (along the direction of gravitation) of Gampsocleis gratiosa foot pads on a vertical glass were measured. It was shown that the average attaching force is 50. 59 mN and the static frictional force is 259. 10 mN. The physical models of the attaching interface between Gampsocleis gratiosa foot pads and the two vertical surfaces were proposed. It was observed that the foot pads are smooth in macroscale; however, the pad surface is composed by approximate hexagonal units with sizes of 3 μm to 7 μm in microscale; the adjacent units are separated by nanoscale grooves. The Observations showed that the Gampsocleis gratiosa can not climb the vertical calcium carbonate wall; in contrast, they can easily climb the vertical glass surface. Based on the features of the geometrical morphologies of the foot pads and the glass surface, we speculate that the attaching force and strong static frictional force are attributed to the inter-inlays between the deformable Gampsocleis gratiosa foot pads and the nanoscale sharp tips of the glass surface.

Natural biomaterials have unique structures and some distinguishing properties for adapting themselves to natural surroundings. Bamboo is a natural composite reinforced with longitudinal fibers (vascular fibers). The abrasive wear property of the cross section of bamboo (Phyllostachys pubescens) stem was examined. The abrasive material used for tests was the mixture of quartz sand (96.5 wt.%) and powdered bentonite (3.5 wt.%) and contained a water content of 3 wt.%, simulating soil condition The size of the quartz sand particles was 0.104–0.214 mm, 0.214–0.420 mm and 0.420–0.840 mm, respectively. The abrasive wear tests were run on a rotary disk type of abrasive wear testing machine. The relative sliding velocity was 1.68, 2.35 and 3.02 m/s, respectively. It was concluded that the abrasive wear resistance of the cross section of the bamboo stem was a function of the vascular fiber content of bamboo, the abrasive particle size and the relative sliding velocity. The wear resistance of bamboo was increased with its vascular fiber content. A higher sliding velocity or a larger abrasive particle size resulted in a higher abraded volume of bamboo. The effects of the tensile strength and the impact strength of bamboo on its abrasive wear were discussed. It was found by scanning electron microscopy that the geometric morphology of the abraded surfaces of the sections of bamboo stem displays a not-smooth structure. This not-smooth surface morphology provides a clue to develop anti-abrasion morphological surfaces of soil-engaging components.

Nacre (known as mother of pearl) is the iridescent inner shell layer of some mollusks. Nacre is composed of 95 wt% aragonite (a crystallographic form of CaCO3) and 5 wt% organic materials (proteins and polysaccharides). It is well known that it exhibits high fracture toughness, much greater than that of monolithic aragonite, because of its ingenious structure. It also exhibits energy absorption properties. It has a complex hierarchical microarchitecture that spans multiple length scales from the nanoscale to the macroscale. It includes columnar architectures and sheet tiles, mineral bridges, polygonal nanograins, nanoasperities, plastic microbuckling, crack deflection, and interlocking bricks, which exhibit a remarkable combination of stiffness, low weight and strength. Nacre's special self-assembly characteristics have attracted interest from materials scientists for the development of laminated composite materials, molecular scale self-assembly and biomineralization. This paper reviews the characteristics of hierarchical structure and the mechanical properties of nacre that provide the desired properties, and the latest developments and biomimetic applications.

To establish the quantitative model of the dragonfly wing the reconfiguration and nanoindentation technique were used. The mechanical properties of wings were measured by nanoindentre. Generally, the costa undertake is mainly pressure, and its mechanical properties should be the largest. However, in the nanoindentation test, the largest value of the reduced modulus (E(r)) and hardness (H) mainly appear in the radius, except the value at 0.7L (L is the wing length). The E(r) and H of the forewing were larger than that of the hindwing, except the value at 0.7L. The reversing engineering (3-D scanner) and AutoCAD were cooperated to reconfigure the dragonfly wing. Then the material parameters and skeleton transforms to a finite element analysis. The quantitative models were discussed in static range.

Natural biomaterials are complex composites in hierarchical structure and multifunction. They have some special structures and functions because of their evolution through the exchanges of energy, matter and information with their surroundings over millions of years. The cuticle represents 25% of the dry weight of the entire insect body. It is tenacity, waterproof and lightweight which is an excellent crude composite material. An increasing interest in bionic design of materials based on structures of natural biomaterials has led to the nanomechanical characterization of biomaterials. Quantitive measurement of mechanical properties of insect cuticle will help to develop biomimetic materials suitable for industrial products. Field emission scanning electron microscopy (FESEM) was used to investigate the detail structure of elytra cross section in transverse direction and longitudinal direction. Shown in transverse direction, the fibers of the deeper layers of the endocuticle are orientated in rotation angle and neighbor fibers are rotated in relation to the each other in the same direction. While the fibers in longitudinal direction show the epicuticle, exocuticle and endocuticle clearly hierarchically structure in parallel. In this work, the mechanical properties of the elytra cuticle of dung beetle Copris ochus Motschulsky, reduced modulus and hardness in nano-scale, were investigated by using a nanoindenter. The reduced modulus (E v ) and hardness (H v ) of surface cuticle in the vertical direction obtained by nanoindentation was 5.96 ± 0.32GPa and 0.32 ± 0.09GPa, respectively. The nanoindentation result was shown that the reduced modulus (E t , E l ) and hardness (H t , H l ) of each layer was gradually reduced from the outer layer to the inner layer in the transverse direction and the longitudinal direction, respectively. E v was less than the largest E t presented at outer layer (7.34 ± 0.27GPa) and was larger than that of E l (6.05 ± 1.12GPa) which shows the anisotropy of chitin fibers. It was supposedly formed as a result of the composite effect of the hierarchically structure.

The surface materials and structures of insect cuticle can provide useful information for designing anti-adhesion components material. Quantitive measurement of mechanical properties of insect cuticle will help to develop biomimetic materials suitable for industrial products. In this work, the mechanical properties of the cuticle of dung beetle Copris ochus Motschulsky, reduced modulus and hardness in nano-scale, were investigated by using a nanoindenter. It was shown that the nanomechanical properties of the cuticle were change with each layer of the cuticle. The modulus and hardness in cross section was gradually reduced from the outer layer to the inner layer. And the value in the outer layer is larger than that in vertical direction. So we can suppose that its vertical nanoindentation was resulted from the composite effect of the all layers.

The nanomechanical properties of the multilayer elytra cuticle of the dung beetle (Copris ochus Motschulsky) were investigated in the vertical and transverse directions using a nano-indenter. The reduced modulus Ev and hardness Hv of the surface cuticle in the vertical direction obtained by nano-indentation were 3.54+/-0.12 GPa and 0.20+/-0.01 GP, respectively. The nano-indentation result showed that the reduced modulus E(t) and hardness Ht of each layer were gradually reduced from the outer layer to the inner layer in the transverse direction. Ev was less than the largest Et presented at the outer layer (7.06+/-0.54 GPa). It was supposedly formed as a result of the composite effect of the multilayer. Without consideration of the anisotropy of chitin, an experimental model was proposed to describe the nanomechanical properties of the elytra cuticle.

Nacre has a complex hierarchical microarchitecture that spans over multiple length scales from nanoscale to macroscale. Its structures are optimized leading to extraordinary mechanical performance and energy absorption. Nacre's special characteristics of the self-assembly method have attracted the interest of material scientists to develop laminated composite materials, molecular scale self-assembly and biomineralization. Nanoindentation testing can determine a material's anisotropic properties through a single indentation. In the present study, nanoindentation stress–strain curves were used to characterize the complete mechanical behavior of nacre of abalone shell. A differential constitutive equation was developed with time-dependent spring constants k and viscosities η. Furthermore, to describe the complex viscoelastic behavior of abalone nacre, a descriptive representation of the linear viscoelasticity law for the multilayer matrix was formulated. A qualitative model for the relationship between nacre structure and mechanical properties of nacre may help develop bionic composite materials for micro-aircraft, bionic tribology, bionic medical apparatus and bionic organs (tissue engineering).

Nacre (known as mother of pearl) is the iridescent inner shell layer of some mollusks. Nacre is composed of 95 wt% aragonite (a crystallographic form of CaCO3) and 5 wt% organic materials (proteins and polysaccharides). It is well known that it exhibits high fracture toughness, much greater than that of monolithic aragonite, because of its ingenious structure. It also exhibits energy absorption properties. It has a complex hierarchical microarchitecture that spans multiple length scales from the nanoscale to the macroscale. It includes columnar architectures and sheet tiles, mineral bridges, polygonal nanograins, nanoasperities, plastic microbuckling, crack deflection, and interlocking bricks, which exhibit a remarkable combination of stiffness, low weight and strength. Nacre's special self-assembly characteristics have attracted interest from materials scientists for the development of laminated composite materials, molecular scale self-assembly and biomineralization. This paper reviews the characteristics of hierarchical structure and the mechanical properties of nacre that provide the desired properties, and the latest developments and biomimetic applications.

The wing cases (elytra) of Dynastes tityus are able to change coloration from yellow-green in a dry state to deep brown in a wet state due to different degrees of water absorption. An environmental scanning electron microscope was used to investigate the elytra’s reversible color change properties. Because the elytra cuticle has a spongy structure that is composed of laminated chitin and protein, a UV–Vis–NIR spectrophotometer was used to investigate the elytra’s optical properties. The width of the curve peak gradually decreased from 60 to 10 nm when the color of the elytra varied from deep brown to yellow-green. In a humid environment, air between the voids was replaced by water with a higher refractive index that induced an elytra color changed from yellow-green to deep brown. Interestingly, when both humidity and elytra color changed, the elytra’s mechanical properties varied too. When the humidity of the environment changed from 100 to 34%, the reduced modulus (E r) and hardness (H) of the elytra increased 230 and 440%, respectively. The storage modulus (E′) of the elytra is 1.98 ± 0.65 and 1.17 ± 0.22 GPa in yellow-green and deep brown color at 10 Hz, respectively, while their loss modulus (E″) is similar. tan δ of deep brown elytra is 0.072 ± 0.017, which is nearly two times higher than that of yellow-green. It can be demonstrated that when the elytra’s color turns to yellow-green, they are more elastic with less energy loss. The relationship between the elytra’s mechanical properties and structure color will not only help us gain insight into the biological functionality of the color change but also inspire the designs of artificial biomimetic devices.