Infrared camouflage is essential in applications exposed to dynamic and complex thermal environments, particularly in military and industrial settings. Conventional static infrared camouflage methods are limited by their fixed emissivity, which is unsuitable for rapidly changing temperature fields. This study presents a metamaterial-based adaptive infrared camouflage film that utilizes polytetrafluoroethylene (PTFE) as a thermally responsive layer. The thickness of the PTFE layer varies with temperature, enabling dynamic modulation of the metamaterial's structural parameters. The metal-dielectric-metal (MDM) structure is designed to couple incident light and actively adjust the material's emissivity, thus achieving effective concealment in infrared imaging. Results demonstrate that at the wavelength of 12.4 μm, the material's emissivity peaks at 0.97 at 0 °C and decreases to 0.05 at 200 °C while maintaining a stable radiative output across the 8–13 μm band despite temperature fluctuations. Within the 0-200 °C range, the metamaterial exhibits maximum and minimum radiant power values of 50.76 W/m2 and 33.55 W/m2, respectively, with an average of 41.07 W/m2 - closely matching the ideal infrared camouflage requirement of 46.61 W/m2. Therefore, this approach enables passive adaptation to complex thermal gradients, providing a superior solution for adaptive infrared camouflage with significant potential for both military and civilian infrared concealment applications.

The colors of objects originate from reflection of light in certain directions and absorption of undesired light, producing substantial heating. Extensive efforts are expended to cool colorful objects to reduce their energy consumption. However, a strategy to cool colorful objects below ambient temperature while fully preserving their excellent color properties with high saturation and large viewing fields remains a significant challenge. Inspired by Morpho butterflies, we report a robust configuration consisting of a multilayer, disordered structure, and total reflection layer to cool colorful objects to overcome this challenge. Numerical simulations and experimental measurements demonstrated that our configuration can cool a class of colorful objects not only to a temperature of approximately 2°C below ambient temperature, but also with ultrahigh saturation (100%) and a wide range of viewing angles (±60 ∘ ). These colorful cooling films have significant potential for energy sustainability in buildings, vehicles, facilities, and equipment.

Wide bandwidth THz pulses can be used to record the distinctive spectral fingerprints related to the vibrational or rotational modes of polycrystalline biomolecules, and can be used to resolve the time-dependent dynamics of such systems. Waveguides, owing to their tight spatial confinement of the electromagnetic fields and the longer interaction distance, are promising platforms with which to study small volumes of such systems. The efficient input of sub-ps THz pulses into waveguides is challenging owing to the wide bandwidth of the THz signal. Here, we propose a sensing chip comprised of a pair of back-to-back Vivaldi antennas feeding into, and out from, a 90° bent slotline waveguide to overcome this problem. The effective operating bandwidth of the sensing chip ranges from 0.2 to 1.15 THz, and the free-space to on-chip coupling efficiency is as high as 51% at 0.44 THz. Over the entire band, the THz signal is ∼42 dB above the noise level at room temperature, with a peak of ∼73 dB above the noise. In order to demonstrate the use of the chip, we have measured the characteristic fingerprint of α-lactose monohydrate, and its sharp absorption peak at ∼0.53 THz was successfully observed, demonstrating the promise of our technique. The chip has the merits of efficient in-plane coupling, ultra-wide bandwidth, ease-of-integration, and simple fabrication. It has the potential for large-scale manufacture, and can be a strong candidate for integration into other THz light-matter interaction platforms.

Photocatalytic degradation by visible-light responsive photocatalysts is an efficient strategy to treat organic dye pollutants and monitoring of the photocatalytic reaction mechanisms and kinetics is important to the design of high-performance photocatalysts. Herein, a dual-functional graphitic carbon nitride/gold nanoparticles (g-C3N4/ AuNPs) nanocomposite film is introduced to monitor the photocatalytic reactions by surface-enhanced Raman scattering (SERS) while degrading organic dyes photocatalytically. The nanocomposite film fabricated by two-step interfacial self-assembly consists of orderly arranged g-C3N4 film anchored on a closely packed AuNPs monolayer film. The nanoplatform has excellent SERS characteristics such as a rhodamine 6G (R6G) detection limit of 8.8 x 10-10 M, and good SERS detection uniformity with a relative standard deviation (RSD) of 9.62%, which is crucial to quantitative determination and accurate monitoring of the photocatalytic reactions. The nanoplatform is employed in visible-light photocatalytic degradation of organic dyes including R6G, methylene blue, acid orange II, and acid orange 74. The reactions follow the pseudo-first-order kinetics as revealed by SERS and the photocatalytic degradation mechanism is postulated to be the promoted charge separation. The results reveal a high-performance dual-functional nanoplatform suitable for visible-light photocatalytic degradation of organic dye pollutants and SERS monitoring of the reactions.

The colors of objects are generally originated from reflecting desired light in the desired direction and absorbing the undesired light, which will substantially produce heating. Many efforts have been made to focus on cooling the colorful objects. However, a cooling strategy to cool colorful objects beyond a limit of temperature below the ambient temperature while fully preserving the excellent color properties of high saturation and large viewing field is still a great challenge, as it is rather difficult to independently control the four light bands simultaneously: high diffusion of desired light, low absorption of undesired complementary visible light, low absorption of near-IR light, and high emission of mid-IR light. Inspired by Morpho butterflies, we reported here a robust configure consisting of a multilayer, a disorder structure, and a total reflection layer to cool colorful objects to overcome the challenge. Numerical simulations and experimental measurements demonstrated that our configure can cool a class of colorful objects to not only a temperature of around 2 °C below the ambient temperature, but also with ultra-high saturations (100%) and a wide range of viewing angles (±60°), indicating a great potential for energy sustainability of colorful objects such as buildings, vehicles, facilities, and equipment.

The colors of objects are generally originated from reflecting desired light in the desired direction and absorbing the undesired light, which will substantially produce heating. Many efforts have been made to focus on cooling the colorful objects. However, a cooling strategy to cool colorful objects beyond a limit of temperature below the ambient temperature while fully preserving the excellent color properties of high saturation and large viewing field is still a great challenge, as it is rather difficult to independently control the four light bands simultaneously: high diffusion of desired light, low absorption of undesired complementary visible light, low absorption of near-IR light, and high emission of mid-IR light. Inspired by Morpho butterflies, we reported here a robust configure consisting of a multilayer, a disorder structure, and a total reflection layer to cool colorful objects to overcome the challenge. Numerical simulations and experimental measurements demonstrated that our configure can cool a class of colorful objects to not only a temperature of around 2 °C below the ambient temperature, but also with ultra-high saturations (100%) and a wide range of viewing angles (±60°), indicating a great potential for energy sustainability of colorful objects such as buildings, vehicles, facilities, and equipment.

Abstract The multispectral compatible infrared camouflage technology is implemented these days to counter the developing infrared detectors and detectors of other bands. However, the conflict between delicate optical structures and scalable procedures has significantly impeded the development and application of multispectral‐compatible camouflage technology. Therefore, a semi‐open Fabry‐Perot structure is introduced, and the color and infrared emissivity by structural parameters for color‐matched visible‐infrared compatible camouflage are modulated. The prepared compatible camouflage film exhibits visible camouflage by the minimum color difference of 1.6 L*a*b* (under desert background) and infrared camouflage by low emission (ε3–5 µm ≈ 0.17 and ε8–14 µm ≈ 0.143). Due to its flexibility and scalability, the compatible camouflage film can be applied in practical applications and exhibits desirable visible and infrared camouflage performance in different battlefield backgrounds.

Color-preserving radiative cooling (CRC) is widely studied as a sustainable technology for outdoor structures due to its energy-saving and aesthetic capacities. Direct sunlight can cause outdoor structures to become extremely hot, leading to high energy consumption for cooling. To address this issue, CRC has been explored as a means to lower the temperature of outdoor structures. However, preserving color under sunlight while achieving excellent cooling performance is a challenging task, as colors absorb undesired visible and near-infrared radiation, thus limiting their cooling effectiveness. In this review, we explore the fundamentals of CRC, including the regulation of color via reflective spectral mechanisms and thermal dissipation processes. Additionally, by focusing on the color and cooling performance in outdoor experiments involving various types of CRC structures, this review conducts an extensive literature survey, summarizing the respective advantages and limitations, which aims to provide a comprehensive understanding of the current state of CRC. Finally, we discuss the challenges that must be overcome in order to enhance the design and production of CRC for a wide range of applications. It is expected that this review will contribute to the development of sustainable energy solutions for outdoor structures.

As one of the most fascinating phenomena, structural whiteness in natural organisms serves important functions in thermoregulation and mating. However, the architectures that cause visible broadband reflection are often in quasiordered distributions, which hinders systematic research on their color formation mechanisms. Here, through numerical analysis, the architectures in Morpho theseus scales are shown to be distributed in various tubular morphologies between tubular and gyroid structures. Then, the mechanism of structural white is discussed using the numerical model built with the combination of a periodic numerical framework and random elements. Thermodynamic experiments indicate that the white scales can efficiently help reduce the temperature of butterfly wings under a direct light beam. Our work provides a concise method for analyzing quasiordered structures. The methodology developed by this numerical model can facilitate a deep understanding of the performance improvement facilitated by these structural characteristics. Corresponding solutions can guide the design of nano-optical materials to achieve an efficient cooling, camouflage, and photothermal conversion system.

Lepidopteran scales exhibit exquisite architectures that produce complex optical performance, such as structural colors for multiple survival strategies. However, how do these optical properties evolve to achieve such an excellent performance remains enigmatic because of the rarity of fossils and complexity of the gene regulatory network. Here, inspired by the primitive lepidopteran fossils, it is deduced that the morphology of these multilayered scales can be expressed by the basic trigonometric function sin( x ) = t . A unified evolving model (UEM) is developed to reconstruct the evolutionary process from original multilayers to the current lepidopteran scale microstructures. The simulated optical response results show that factors such as the light absorption, warning coloration, and visual range intensity are optimized for survival by these insect individuals. The UEM provides a route to rationalizing other natural periodic microstructures. Furthermore, microstructure parameterization can facilitate the design of the nano‐optical materials. Corresponding results can help develop specific applications such as photothermal conversion, radiative cooling, and camouflaging.

The rapidly growing global data usage has demanded more efficient ways to utilize the scarce electromagnetic spectrum resource.Recent research has focused on the development of efficient multiplexing techniques in the millimeter-wave band(1-10 mm,or 30-300 GHz)due to the promise of large available bandwidth for future wireless networks.Frequency-division multiplexing is still one of the most commonly-used techniques to maximize the transmission capacity of a wireless network.Based on the frequency-selective tunnelling effect of the low-loss epsilon-near-zero metamaterial waveguide,we numerically and experimentally demonstrate five-channel frequency-division multiplexing and demultiplexing in the millimeter-wave range.We show that this device architecture offers great flexibility to manipulate the filter Q-factors and the transmission spectra of different channels,by changing of the epsilon-near-zero metamaterial waveguide topology and by adding a standard waveguide between two epsilon-near-zero channels.This strategy of frequency-division multiplexing may pave a way for efficiently allocating the spectrum for future communication networks.

A gyroid-structured Au–Ag bimetal plasmonic material GSPMMs@Au demonstrates ultrasensitive SERS detection performance due to plasmonic coupling between the Au–Ag interface and gyroid structure with high-density hotspots.

The temperature of outdoor structures, such as automobiles, buildings, and clothing, can be tuned by designing photonic properties. However, particular challenges arise when considering the temperature of an object itself rather than the enclosure in these outdoor structures. We present a double-side photonic thermal (DSPT) system. In the DSPT system, the tunable range of photonic thermal load for heating and cooling functions is calculated by designing the absorption spectra of both sides to adapt to different temperature conditions. These include the proper photonic design of not only the side facing outward but also the inner side and more complex temperature conditions of the object, enclosures, and atmosphere. According to the DSPT mechanisms, we developed a Janus material that can achieve the opposite functions (cooling and heating) with one film by simply flipping the sides of the Janus material, which does not require any additional energy input. The Janus material is designed and fabricated by common materials and a simple multilayer structure, which is attractive for large-scale fabrication. The thermal experiment proved the Janus multilayer could achieve a high temperature in the heating mode and a low temperature in the cooling mode, and the range of the tunable temperature would be wider with stronger sun radiation. The Janus material can passively achieve more efficient temperature control in enclosures while offering both side photonic design comparable to conventional radiative coolers and heaters.

Inspired by the tunable coupling of pigment cells and iridocytes, a tunable thermoregulatory material is designed. The metamaterial can tune the solar absorptive quality from 0.9 to 0.03 while keeping the radiative quality small.

A conceptive design of self-adaptive photonic thermal management can keep cool under high temperature and keep warm under low temperature with the compound metasurface.

Surface plasmon resonance (SPR), a promising technology, is beneficial for various applications, such as photothermal conversion, solar cells, photocatalysts, and sensing. However, the SPR performance may be restricted by the 1D- or 2D-distributed hotspots. The bicontinuous interconnected gyroid-structured materials have emerged in light energy conversion due to a high density of 3D-distributed hotspots, ultrahigh light-matter interactions and large scattering cross-section. Here, a series of bioinspired Au-CuS gyroid-structured materials are fabricated by precisely controlling the deposition time of CuS nanoparticles (NPs) and then adopted for solar steam generation. Specifically, Au-CuS/GMs-80 present the highest evaporation efficiency of 88.8% under normal 1 sun, with a suitable filling rate (57%) and a large inner surface area (∼2.72 × 105 nm2 per unit cell), which simultaneously achieves a dynamic balance between water absorption and evaporation as well as efficient heat conduction with water in nanochannels. Compared with other state-of-the-art devices, Au-CuS/GMs-80 steam generator requires a much lower photothermal component loading (<1 mg cm-2) and still guarantees outstanding evaporation performance. This superior evaporation performance is attributed to broadband light absorption, continuous water supply, excellent heat generation and thermal insulation, and good light-heat-water interaction. The combination of 3D interconnected nanostructures with controllable metal-semiconductor deposition could provide a new method for the future design of high-performance plasmonic devices.

The amorphous/nanocrystal hybrid TiO2 based butterfly wing structure (ANH-TiO2-BW) is successfully fabricated via an easily controlled self-deposition sintering method.

Ultrathin transition metal carbides with high capacity, high surface area, and high conductivity are a promising family of materials for applications from energy storage to catalysis. However, large-scale, cost-effective, and precursor-free methods to prepare ultrathin carbides are lacking. Here, we demonstrate a direct pattern method to manufacture ultrathin carbides (MoC x , WC x , and CoC x ) on versatile substrates using a CO 2 laser. The laser-sculptured polycrystalline carbides (macroporous, ~10–20 nm wall thickness, ~10 nm crystallinity) show high energy storage capability, hierarchical porous structure, and higher thermal resilience than MXenes and other laser-ablated carbon materials. A flexible supercapacitor made of MoC x demonstrates a wide temperature range (−50 to 300 °C). Furthermore, the sculptured microstructures endow the carbide network with enhanced visible light absorption, providing high solar energy harvesting efficiency (~72 %) for steam generation. The laser-based, scalable, resilient, and low-cost manufacturing process presents an approach for construction of carbides and their subsequent applications.

Nature provides abundant photonic structures which give a great inspiration on the synthesis of stimuli-responsive photonic crystals (PCs) with unique structures. However, the intrinsic effects of microstructures on the responsive properties of the hierarchical PCs are still not clear. Herein, the relationship between the photonic structures and the responsive properties is investigated by choosing three natural photonic structures replicated from templates, Morpho Menelaus and Morpho peleides both with a 1D tree-like hierarchical structure while having eight and four layers, respectively and Papilio paris, with an eight layered 1D concave structure. Humidity responsive PCs were prepared by in-situ polymerizing polyacrylamide (PAAm) onto the surface of the butterfly wing scales. The 1D concave (Papilio paris) structured PCs exhibited a higher humidity sensitivity: a wavelength redshift of 92 nm when the relative humidity rose from 11 to 97 %, as compared with the Morpho menelaus PCs, which have about 70 nm redshift for the same rise of the relative humidity. The eight layer 1D tree-like structured Morpho menelaus PCs had a higher reflectance intensity. The results were also supported by a finite-difference time-domain (FDTD) simulation. This work paves a new avenue to design responsive PCs with a diversity of structures from nature and controllable responsive properties.