Optical diffusers are widely used in a variety of light sources to create uniform illumination over a wide field of view. Inspired by the diffraction-based light diffusion of the Morpho butterfly, here we demonstrate a novel diffuser which fulfils (i) high transmittance, (ii) wide angular spread, and (iii) low color dispersion. Two-dimensional nanopatterns were designed using optical simulations to enable simple fabrication. By introducing anisotropy into the surface nanopatterns, we achieved control of anisotropic light diffusion, which has been challenging for conventional diffusers. Next, the designed diffuser was implemented over a large area (100 × 100 mm2) via nanoimprint lithography. The obtained diffuser demonstrated a high transmittance of ∼85% and full width at half maximum (FWHM) of >60° with low color dispersion, outperforming conventional diffusers. Since the presented diffuser has the controllable diffusion properties with low light loss, it has many applications including LED lighting, displays, and daylight harvesting systems.

Lipid nanoparticles (LNPs) are currently in the spotlight as delivery systems for mRNA therapeutics and have been used in the Pfizer/BioNTech and Moderna COVID-19 vaccines. mRNA-LNP formulations have been indicated to require strict control, including maintenance at fairly low temperatures during their transport and storage. Since it is a new pharmaceutical modality, there is a lack of information on the systematic investigation of how storage and handling conditions affect the physicochemical properties of mRNA-LNPs and their protein expression ability. In this study, using the mRNA-LNPs with standard composition, we evaluated the effects of temperature, cryoprotectants, vibration, light exposure, and syringe aspiration from the vials on the physicochemical properties of nanoparticles in relation to their in vitro/in vivo protein expression ability. Among these factors, storage at −80 °C without a cryoprotectant caused a decrease in protein expression, which may be attributed to particle aggregation. Exposure to vibration and light also caused similar changes under certain conditions. Exposure to these factors can occur during laboratory and hospital handling. It is essential to have sufficient knowledge of the stability of mRNA-LNPs in terms of their physical properties and protein expression ability at an early stage to ensure reproducible research and development and medical care.

Some species of Morpho butterflies reflect interfered brilliant blue, which is contradictory to the interference effect due to low angular dependence. This coloration is typically attributed to the disordered nanostructure of the species scales. Applying this reflective principle into light transmission, we discover a new daylight window with high transmittance, wide angular spread, and low color dispersion. The effectiveness of this window was verified through numerical simulations. The optical conditions were investigated by changing the structural parameters, and the required conditions were clarified. This concept realizes an ideal window based on a new principle.

Morpho butterflies are well known for their brilliant blue color that has a low angular dependence. This distinctive coloration has long been attributed to the skillful combination of order and disorder in the hierarchical nanostructures, which allows the interference of light to avoid iridescence. However, there remains a fundamental mystery: the artificial Morpho-blue color is successfully obtained despite the lack of vertical randomness. Using a numerical simulation, we found that the three-dimensional randomness can be converted to a two-dimensional randomness. This finding leads to a novel approach for the simple nanofabrication of not only Morpho-blue but also of more general photonic devices.

Morpho butterfly’s blue is a famous example of structural colors but its mechanisms are exceptional, accompanied with a mystery. This color is created by interference from an ordered nanostructure, whereas the single color in wide angles contradicts the interference. This secret is attributed to a specific nanostructure having both order and disorder. After proof of this mechanism by artificial reproduction, we have found its wide potential applicability, and developed the fabrication technology in several directions. Moreover, converting this reflective principle to transmission, we have also found a possibility of new optical transmission devices with high transmittance, wide angular spread, low color dispersion, compactness, and controllability of light spread which have been impossible to meet simultaneously. Although our originally proposed nanostructure was difficult to fabricate, we have designed a feasible nanostructure to solve the problem. Finally, a Morpho-type window was successfully fabricated and verified, which can serve as a novel optical diffuser.