State Key Lab of Metal Matrix Composites, School of Materials Science and Engineering, Shanghai Jiao Tong University, No. 800 Dongchuan Road, Shanghai, 200240, China.
Soft Matter. 2019 May 29;15(21):4294-4300. doi: 10.1039/c9sm00566h.
Structural whiteness, stemming from biologically evolutionarily refined structures, provides inspiration for designing promising, reflectance-based materials. White beetles Goliathus goliatus, which can survive in high-temperature-equatorial forests, may suggest undiscovered new physical mechanisms for thermoregulation. Their scales' whiteness is created by the exquisite shell/hollow cylinder structure with two thermoregulatory effects, contributing to a lower equilibrium temperature of elytra under direct sunlight. In the visible regime, they enhance the broadband omnidirectional reflection significantly by synergetic structural effects originating from the thin-film interference, Mie resonance and total reflection. In the mid-infrared (MIR) regime, white scales act as antireflective layers to increase the emissivity in the MIR range, enabling the elytra to reradiate heat to the environment and help the beetles reduce their temperature by as much as ∼7.8 °C in air. These biological strategies for thermoregulation could provide new approaches for bioinspired coatings towards passive radiative cooling.
结构白色，源自生物进化精细的结构，为设计有前途的基于反射率的材料提供了灵感。能够在高温赤道森林中生存的巨型 Goliathus 甲虫，可能为体温调节提供了尚未发现的新物理机制。它们的鳞片的白色是由具有两种热调节作用的精致外壳/空心圆柱结构产生的，有助于降低在阳光直射下鞘翅的平衡温度。在可见光范围内，它们通过源自薄膜干涉、米氏共振和全反射的协同结构效应，显著增强了宽带各向同性反射。在中红外（MIR）范围内，白色鳞片作为抗反射层，增加 MIR 范围内的发射率，使鞘翅能够将热量重新辐射到环境中，并帮助甲虫将空气温度降低约 7.8°C。这些用于体温调节的生物策略可以为仿生涂层提供新的方法，以实现被动辐射冷却。
