蚊子复眼的防雾原理

Antifogging Mechanism of Mosquito Compound Eyes

蚊子复眼具有超疏水性和防雾功能,主要归功于蚊子复眼具有特殊的微、纳米分级结构。建立了复眼的微、纳米分级结构模型;并从界面疏水稳定性和热力学的角度进行了分析。界面稳定性分析表明蚊子眼微米和纳米级结构可抵抗的最大压力分别为67.2 k Pa和181 k Pa,能够有效地抵御外部雾滴的润湿。对于纳米尺度的小雾滴,由于受尺度和线张力的影响,类Wenzel状态的自由能高于类Cassie状态,因此在雾化过程中总是形成类Cassie状态,并进而形成Cassie状态。由于微米结构特别的半球形状和紧密排列,能够形成锥形疏水毛细管,这一锥形毛细管能够在雾滴长大过程中将雾滴从微结构内部排出,从而实现防雾。蚊子复眼上小尺度的纳米结构是实现防雾的基础和关键。

Mosquito compound eyes are superhydrophobic and antifogging,these are attributed to the special mi-cro- and nanoscale hierarchical structure of mosquito compound eyes. The model of micro- and nanoscale hierarchi-cal structures for compound eyes, is establish and analysis it in the views of stability of interracial hydrophobicityand thermodynamics. The analysis of interracial stability shows the micronscale and nanoscale structures can resistexternal pressures of 67.2 kPa and 181 kPa respectively,which can effectively resist the wetting from external fogdrops. For the fog drops at nanoscale, influenced by the scale effect and line tension, the free energy of analogousWenzel state is higher than the analogous Cassie state. Therefore,the analogous Cassie state is always formed priorand then the Cassie state is formed during the atomization. Due to the hemisphere shape and close arrangement ofmicrostructure, a conical hydrophobic capillary tube is formed,which can push out the fogdrop from the inside of themicrostructures when the fog drop is grown up, and therefore the antifogging property is realized at micron scale. Thesmall sized nanostructure of mosquito compound eyes is the key factor for the realization of antifogging property.