The nano-hole array structure in the black scales of the butterfly can be viewed as a natural solar collector. A low-cost, high-efficiency light absorption structure, inspired by the Papilio ulysses butterfly, was optimized using a finite-difference time-domain method. The results show that the nano-hole structure of Papilio ulysses contributes to light absorption. The shape of the holes affects the angular dependence of absorption. The absorption efficiency was found to be strongly affected by three parameters: H (the depth of the hole), D (the thickness of the hole-wall) and L (the size of the hole). These parameters were swept together in numerous simulations. The optimized nano-hole array saves 84% more material than a thin film of equal absorption (90%) at a wavelength of 600 nm.

In this study, the carbon-matrix Ag wing with a hierarchical sub-micron antireflection quasi-photonic crystal structure (HSAS) was fabricated by a simple and promising method. This method combines chemosynthesis with biomimetic techniques, without the requirement of expensive equipment and energy intensive processes. Here, the Troides helena (Linnaeus) (T. helena) forewing (T_FW) was chosen as the biomimetic template. The carbon-matrix Ag butterfly wing (Ag@C_T_FW) achieves a drastically enhanced infrared absorption over a broad spectral range, especially, over the near infrared region. Here, we report methods to enhance and modify the plasmonic resonances in such structures by strongly coupling plasmonic resonances to HSAS. Using the finite difference time domain (FDTD) method, the absorption spectra and the distribution of the energy density near the Ag NPs surface were simulated. Based on the experiment and simulation results, these findings demonstrate that the enhanced infrared absorption over a broad spectral range is due to the mechanism that the plasmon and the coherent coupling between adjacent resonance systems integrate with the HSAS.

A tin oxide multi-tube array (SMTA) with a parallel effect was fabricated through a simple and promising method combining chemosynthesis and biomimetic techniques; a biomimetic template was derived from the bristles on the wings of the Alpine Black Swallowtail butterfly (Papilio maackii). SnO2 tubes are hollow and porous structures with micro-pores regularly distributed on the wall. The morphology, the delicate microstructure and the crystal structure of this SMTA were characterized by super resolution digital microscopy, scanning electron microscopy, transmission electron microscopy and X-ray diffraction. The SMTA exhibits a high sensitivity to H2S gas at room temperature. It also exhibits a short response/recovery time, with an average value of 14/30 s at 5 ppm. In particular, heating is not required for the SMTA in the gas sensitivity measurement process. On the basis of these results, SMTA is proposed as a suitable new material for the design and fabrication of room-temperature H2S gas sensors.

•The enhanced broadband infrared absorption was explained by the plasmon-to-exciton/plasmon coupling effect and the coherent coupling between adjacent resonant systems integrated with a sub-micrometer antireflection quasi-photonic crystal structure (SAPS) of the T.helena forewing scales (T_FW). Furthermore, the coupling effect of the Au NPs and CuS NPs integrate with the SAPS of T_FW to enhance the light absorption over a broadband range is demonstrated by finite-difference time-domain simulation (FDTD). Consequently the mechanism that the plasmon-to-exciton/plasmon coupling effect and the coherent coupling between adjacent resonant systems integrated with the SAPS of T_FW enhance broadband infrared absorption which proposed in our manuscript, was confirmed by both of experimental results and simulation results. The Au–CuS_T_FW_APCF possesses a more superior absorptance (98%) compared with some non-commercially available (Sol. Energy Mater. Sol. Cells 2013, 109, 97; J. Am. Ceram. Soc. 2011, 94, 827; and so on. As shown in Table S2) and commercially available absorbers of solar collectors when their emittances are less than 0.600.•The best infrared photothermal transfer efficiency (30.56%) and an effective sunlight photothermal conversion for the low temperature applications (T<60 °C) was reported ever with the comparative high emission ration. These results can be found that the Au–CuS_T_FW not only possesses a predominant infrared photothermal conversion performance, but also is effective for photothermal conversion of solar energy, for the low temperature applications (T<60 °C).•We firstly combined the FDTD method with the Joule effect to simulate the photothermal conversion. By numerical simulation based on FDTD method and the Joule effect, we find that the more intensive heat source density distribute on the adjacent region between two plasmonic structures and the coherent coupling between adjacent resonant systems enhance hot power yield. In addition, the most hot power yields of the Au–CuS_T_W arise from the photothermal materials which covered on the surface of the ridges of the T_FW.•Potential macro centimeter-scale reproduction of the infrared absorption and photothermal film with 5 cm*5 cm.The super properties of broadband sunlight absorption and efficient photothermal conversion also can be utilized to the photovoltaic systems, thermophotovoltaic systems, IR imaging and more.A macro centimeter-scale Au–CuS combination nanoparticle system integrated with a sub-micrometer antireflection quasi-photonic structure (SAPS) was synthesized for the first time by utilizing T. helena forewings (T_FW) as a biomimetic template (Au–CuS_T_FW). As-fabricated Au–CuS_T_FW exhibits enhanced broadband infrared absorption and lowered reflectance performance. Such an improvement is attributed to the plasmon-to-exciton/plasmon coupling effect among the Au and CuS nanoparticles as well as the coherent coupling between adjacent resonant systems integrated with the SAPS of the T_FW. Moreover, the Au–CuS_T_FW not only possesses a predominant infrared photothermal conversion performance (30.56%), but also is effective for solar photothermal conversion, for low-temperature applications (T<60 °C). Furthermore, the plasmon coupling effect integrates with the SAPS to enhance broadband infrared absorption, and the coherent coupling between adjacent resonant systems enhances the hot power yield, both of which were demonstrated by numerical simulation. Our results offer a new research direction for absorbing and utilizing infrared light and open a novel pathway for improving the absorber of the solar thermal collectors for sunlight photothermal and photoelectric conversion, especially over the infrared range.

Templated from the bristles on Papilio maacki wings, single porous SnO2 microtubes (SPSMs) have been synthesized by soaking and sintering. The delicate microstructure and morphology of SPSMs were characterized by SEM and TEM. Silver electrodes were precisely contacted on the two ends of an SPSM for gas-sensing measurement in reducing gases. The SPSMs were highly sensitive to trace ammonia, formaldehyde, and ethanol at room temperature. They also exhibited low working temperature and short response/recovery times. The average response and recovery times were only about 3 s and 30 s. Compared with the non-porous structure and the filled structure, the SPSMs showed higher sensitivity. The fascinating biomorphic structure of the SPSMs will open a new way for the design and application of sensor devices for the detection of harmful and toxic gases.

We demonstrate a simple and promising method for the preparation of large-area natural microstructured Fe-wings which combines biotemplating and biomimetic techniques using natural structures as templates. The replicas were robust and hydrophobic, and also possessed excellent magnetic properties. The micro-structures of the wing scales were accurately retained. Then these replicas were used as stamps to transcribe their micro-structures to the surface of polydimethylsiloxane (PDMS), and the stamps were subsequently separated from the PDMS with ease by a magnet. In this method, as the samples are not detached from the PDMS elastomer by mechanical means, the microstructure of PDMS is not destroyed, and levels of anti-counterfeiting can be improved distinctly by adjusting the imprinting parameters.

In this work, we demonstrated a novel surface-enhanced Raman scattering (SERS) substrate inspired by natural nanostructures of butterfly wing scales. By facile and low-cost procedures, we synthesized the substrate composed of tin dioxide (SnO2) and silver (Ag) nanoparticles (NPs). Micrographs and composition analyses exhibited the morphologies of Ag-Biomorphic SnO2 which inherited the natural three-dimension (3D) periodic nanostructures, and characterized the elemental information of the nanocomposites. SERS spectra were measured by using rhodamine 6G (R6G) as analyte molecules. The satisfying sensibility (with the enhancement factor about 106) and good reproducibility of this SERS-active substrate revealed the effectiveness of our work. It is expected that this substrate would be a potential candidate for relative applications.Highlights► Biomorphic SnO2 was fabricated by using butterfly wing scales as bio-templates. ► We synthesized Ag-Biomorphic SnO2 nanocomposites as the SERS substrate. ► The Ag-Biomorphic SnO2 substrate owns satisfying SERS performances.

In this paper, the reflectance of the butterfly wings are measured by using the microspectrophotometer as the optical character with the reflectance on several scales on the wings. Reflectance spectra from different wing scale zones with the same color are dramatically different. And it suggests that the tiny structural difference has the great influence on the reflectance property. In addition, the microstructures of the butterfly wings can be simplified to a 2D crossing grating. By simulating a two-dimensional model using rigorous coupled-wave analysis technique, the optical properties of the butterfly wings were investigated. The simulation results depend strongly on the structural parameters and refractive index. The research will reveal the mechanisms of the structural color of 2D crossing grating butterfly wings.

In this study, the carbon-matrix Ag wing with a hierarchical sub-micron antireflection quasi-photonic crystal structure (HSAS) was fabricated by a simple and promising method. This method combines chemosynthesis with biomimetic techniques, without the requirement of expensive equipment and energy intensive processes. Here, the Troides helena (Linnaeus) (T. helena) forewing (T_FW) was chosen as the biomimetic template. The carbon-matrix Ag butterfly wing (Ag@C_T_FW) achieves a drastically enhanced infrared absorption over a broad spectral range, especially, over the near infrared region. Here, we report methods to enhance and modify the plasmonic resonances in such structures by strongly coupling plasmonic resonances to HSAS. Using the finite difference time domain (FDTD) method, the absorption spectra and the distribution of the energy density near the Ag NPs surface were simulated. Based on the experiment and simulation results, these findings demonstrate that the enhanced infrared absorption over a broad spectral range is due to the mechanism that the plasmon and the coherent coupling between adjacent resonance systems integrate with the HSAS.

A tin oxide multi-tube array (SMTA) with a parallel effect was fabricated through a simple and promising method combining chemosynthesis and biomimetic techniques; a biomimetic template was derived from the bristles on the wings of the Alpine Black Swallowtail butterfly (Papilio maackii). SnO2 tubes are hollow and porous structures with micro-pores regularly distributed on the wall. The morphology, the delicate microstructure and the crystal structure of this SMTA were characterized by super resolution digital microscopy, scanning electron microscopy, transmission electron microscopy and X-ray diffraction. The SMTA exhibits a high sensitivity to H2S gas at room temperature. It also exhibits a short response/recovery time, with an average value of 14/30 s at 5 ppm. In particular, heating is not required for the SMTA in the gas sensitivity measurement process. On the basis of these results, SMTA is proposed as a suitable new material for the design and fabrication of room-temperature H2S gas sensors.

Templated from the bristles on Papilio maacki wings, single porous SnO2 microtubes (SPSMs) have been synthesized by soaking and sintering. The delicate microstructure and morphology of SPSMs were characterized by SEM and TEM. Silver electrodes were precisely contacted on the two ends of an SPSM for gas-sensing measurement in reducing gases. The SPSMs were highly sensitive to trace ammonia, formaldehyde, and ethanol at room temperature. They also exhibited low working temperature and short response/recovery times. The average response and recovery times were only about 3 s and 30 s. Compared with the non-porous structure and the filled structure, the SPSMs showed higher sensitivity. The fascinating biomorphic structure of the SPSMs will open a new way for the design and application of sensor devices for the detection of harmful and toxic gases.

We demonstrate a simple and promising method for the preparation of large-area natural microstructured Fe-wings which combines biotemplating and biomimetic techniques using natural structures as templates. The replicas were robust and hydrophobic, and also possessed excellent magnetic properties. The micro-structures of the wing scales were accurately retained. Then these replicas were used as stamps to transcribe their micro-structures to the surface of polydimethylsiloxane (PDMS), and the stamps were subsequently separated from the PDMS with ease by a magnet. In this method, as the samples are not detached from the PDMS elastomer by mechanical means, the microstructure of PDMS is not destroyed, and levels of anti-counterfeiting can be improved distinctly by adjusting the imprinting parameters.