Wang Bo, Yang Jinzhao, Zhang Jie, Ke Zetao, Zhang Huafang, Yang Yunqiang, Wu Jianing
School of Aeronautics and Astronautics, Sun Yat-Sen University, 518107 Shenzhen, People's Republic of China.
School of Engineering and Technology, China University of Geosciences (Beijing), 100083 Beijing, People's Republic of China.
Bioinspir Biomim. 2022 Nov 24;18(1). doi: 10.1088/1748-3190/ac9fb3.
A bee's tongue is coated in dynamic hairs that gradually unfold to entrain the viscid nectar, during which hairs inevitably deflect as a result of fluid drag. The hair deflection induced decline in nectar capture rate may be a coupled elastoviscous problem and remains poorly understood. Here we employed geometric beam theory coupled with the effective viscous force to derive a dynamic model for a rotary tongue hair deflection in a viscous fluid. Considering deflection of the tongue hair, we rationalized the nectar capture rate by takingas a model system. When the nectar concentration increases from 20% to 70%, the nectar capture rate declines by 87%, indicating that hair erection is more severely impeded in thicker nectar. Based on this model, we predicted an optimal hair length with which the bee can reach the maximum nectar capture rate. This work may provide a new theoretical framework for quantifying viscous liquid transport by hairy surfaces and shed light on design methodologies for fluid transport devices using hairy beds.
蜜蜂的舌头覆盖着动态毛发，这些毛发会逐渐展开以夹带粘性花蜜，在此过程中，由于流体阻力，毛发不可避免地会发生偏转。毛发偏转导致花蜜捕获率下降可能是一个耦合的弹粘性问题，目前仍知之甚少。在这里，我们采用几何梁理论并结合有效粘性力，推导出粘性流体中旋转舌毛偏转的动态模型。考虑到舌毛的偏转，我们以一个模型系统为基础，合理地解释了花蜜捕获率。当花蜜浓度从20%增加到70%时，花蜜捕获率下降了87%，这表明在较浓稠的花蜜中，毛发竖起受到的阻碍更大。基于这个模型，我们预测了一个最佳毛发长度，蜜蜂可以通过这个长度达到最大的花蜜捕获率。这项工作可能为量化有毛表面的粘性液体传输提供一个新的理论框架，并为使用毛层的流体传输装置的设计方法提供启示。
