Challita Elio J, Bhamla M Saad
Chemical & Biomolecular Engineering, Georgia Institute of Technology, Georgia 30332, Atlanta.
Proc Natl Acad Sci U S A. 2024 Mar 26;121(13):e2317878121. doi: 10.1073/pnas.2317878121. Epub 2024 Mar 11.
Can insects weighing mere grams challenge our current understanding of fluid dynamics in urination, jetting fluids like their larger mammalian counterparts? Current fluid urination models, predominantly formulated for mammals, suggest that jetting is confined to animals over 3 kg, owing to viscous and surface tension constraints at microscales. Our findings defy this paradigm by demonstrating that cicadas-weighing just 2 g-possess the capability for jetting fluids through remarkably small orifices. Using dimensional analysis, we introduce a unifying fluid dynamics scaling framework that accommodates a broad range of taxa, from surface-tension-dominated insects to inertia and gravity-reliant mammals. This study not only refines our understanding of fluid excretion across various species but also highlights its potential relevance in diverse fields such as ecology, evolutionary biology, and biofluid dynamics.
体重仅几克的昆虫能否挑战我们目前对排尿流体动力学的理解，像体型更大的哺乳动物同类一样喷射液体？目前主要为哺乳动物制定的流体排尿模型表明，由于微观尺度下的粘性和表面张力限制，喷射仅限于体重超过3千克的动物。我们的研究结果打破了这一范式，证明体重仅2克的蝉能够通过非常小的孔口喷射液体。通过量纲分析，我们引入了一个统一的流体动力学缩放框架，该框架适用于从以表面张力为主的昆虫到依赖惯性和重力的哺乳动物等广泛的生物分类群。这项研究不仅完善了我们对不同物种流体排泄的理解，还突出了其在生态学、进化生物学和生物流体动力学等不同领域的潜在相关性。
