The Role of Adaptive-Deformation of Water Strider Leg in Its Walking on Water

Abstract

A recent experiment (X. F. Gao and L. Jiang, Nature 432, 36 (2004)) showed that a water strider statically standing on water can bear a load up to 60 times its body weight with its middle and hind legs, which tread deep puddles without piercing the water surface. This fact has been ascribed to the superhydrophobicity of the water strider legs. In the present paper, this viewpoint is argued by our comparative experiments using real water strider legs with superhydrophobicity and artificial legs made of wax-coated steel wires with a much smaller Young's contact angle. It is found that the adaptive-deformation capacity of the real leg through its three joints makes a more important contribution to the superior load-bearing ability than the superhydrophobicity. This conclusion is also demonstrated by our theoretical analysis.