蛇用于滑行的物理机制一直是激烈争论的主题。此前的分析假定蛇推动岩石和树木从而把它们推向前方。
David Hu及其同事审视了蛇如何运动，并提出蛇的皮肤导致的摩擦力在它把自己从平面上向前推进的能力中起了关键作用。蛇利用许多技巧运动。Hu的研究组把注意力放在了“横向起伏”，即蛇用它的腹部横向压迫一个物体，从而把它推向前方。为了检验他们的这个假说，这组作者利用了10条幼年的pueblan奶蛇，并测试了当这些蛇的腹部鳞片被类似厚度和粗糙度的布覆盖之后、以及当它们的鳞片被更光滑的纤维板覆盖之后它们的滑行能力。
这组作者证明了腹部鳞片执行了关键的功能：它们挂住粗糙表面的不规则处，这帮助蛇横向滑行。这些发现提供了无肢运动的基础，这可能导致开发出类似于蛇的机器人机体，能够在沙地（它缺乏明显的推动点）等平面上滑行。（生物谷Bioon.com）
生物谷推荐原始出处：
PNAS June 8, 2009, doi: 10.1073/pnas.0812533106
The mechanics of slithering locomotion
David L. Hua,b,1, Jasmine Nirodya, Terri Scotta and Michael J. Shelleya
aApplied Mathematics Laboratory, Courant Institute of Mathematical Sciences, New York University, New York, NY 10003; and
bDepartments of Mechanical Engineering and Biology, Georgia Institute of Technology, Atlanta, GA 30332
Abstract
In this experimental and theoretical study, we investigate the slithering of snakes on flat surfaces. Previous studies of slithering have rested on the assumption that snakes slither by pushing laterally against rocks and branches. In this study, we develop a theoretical model for slithering locomotion by observing snake motion kinematics and experimentally measuring the friction coefficients of snakeskin. Our predictions of body speed show good agreement with observations, demonstrating that snake propulsion on flat ground, and possibly in general, relies critically on the frictional anisotropy of their scales. We have also highlighted the importance of weight distribution in lateral undulation, previously difficult to visualize and hence assumed uniform. The ability to redistribute weight, clearly of importance when appendages are airborne in limbed locomotion, has a much broader generality, as shown by its role in improving limbless locomotion.
