Steinmann T, Casas J, Krijnen G, Dangles O
Institut de Recherche sur la Biologie de l'Insecte-UMR CNRS 6035, Faculté des Sciences et Techniques, Université François Rabelais, Parc de Grandmont Avenue Monge, 37200 Tours, France.
J Exp Biol. 2006 Nov;209(Pt 21):4398-408. doi: 10.1242/jeb.02506.
The aim of this work is to characterize the boundary layer over small appendages in insects in longitudinal and transverse oscillatory flows. The problem of immediate interest is the early warning system in crickets perceiving flying predators using air-flow-sensitive hairs on cerci, two long appendages at their rear. We studied both types of oscillatory flows around small cylinders using stroboscopic micro-particle image velocimetry as a function of flow velocity and frequency. Theoretical predictions are well fulfilled for both longitudinal and transverse flows. Transverse flow leads to higher velocities than longitudinal flow in the boundary layer over a large range of angles between flow and cylinder. The strong spatial heterogeneity of flow velocities around filiform-shaped appendages is a rich source of information for different flow-sensing animals. Our results suggest that crickets could perceive the direction of incoming danger by having air-flow-sensitive hairs positioned around their entire cerci. Implications for biomimetic flow-sensing MEMS are also presented.
这项工作的目的是表征昆虫小附肢在纵向和横向振荡流中的边界层。当前直接相关的问题是蟋蟀的预警系统，即蟋蟀利用位于其尾部的两个长附肢——尾须上对气流敏感的刚毛来感知飞行中的捕食者。我们使用频闪显微粒子图像测速技术，研究了小圆柱体周围两种类型的振荡流，该技术是流速和频率的函数。纵向流和横向流的理论预测都得到了很好的验证。在流动与圆柱体之间的大范围角度内，横向流在边界层中产生的速度高于纵向流。丝状附肢周围流速的强烈空间异质性是不同流动感知动物丰富的信息来源。我们的结果表明，蟋蟀可以通过在整个尾须周围布置对气流敏感的刚毛来感知危险来袭的方向。本文还阐述了对仿生流动传感微机电系统的启示。
