SUMMARY

We propose a combined experimental and theoretical investigation to test the hypothesis that a snake's scales increase the efficiency of its locomotion. Snakes are one of the world’s most versatile locomotors, at ease slithering through rubble or ratcheting up vertical tree trunks. In our experimental study, we will measure the frictional properties of several species of snakes as well as the kinematics of their locomotion. We have conducted experiments to show that snakes' scales can dig into the underlying surface to prevent sliding. We will use this novel paradigm, the active control of scales to modify frictional properties, to design Scalybot, a two-link limbless robot with individually controlled sets of belly scales. In our supporting theoretical study, we will provide a dynamic model of snakes' locomotion to predict its speed and the forces it applies to its environment. We will focus on common modes of a snake's motion such as concertina and rectilinear. Special attention is given to distinguishing passive mechanisms (snake's geometry and frictional properties) from active mechanisms (control of scale angle of attack and coordination of the body).