The humble gecko makes walking across sand look like a walk in the park. Whereas most animals would sink the lizard stays on the surface. Daniel Goldman, an assistant professor of physics at Georgia Tech, wants to learn the gecko's secrets. So he's building a computer model to replicate the behaviour of sand granules when they meet the forces exerted by animals in motion. (SOUNDBITE) (English) DANIEL GOLDMAN, ASSISTANT PROFESSOR OF PHYSICS, GEORGIA TECH, SAYING: "It turns out that there are a lot of organisms like lizards, like beetles, like scorpions, that inhabit deserts made of dry components like sand, dry granules material and these animals move on the surface of these materials as well as bury within or even swim within, and the principles in which they do that are largely unknown." To find answers, Goldman and his team put a variety of reptiles through their paces and used high speed cameras to record their movement across the sand. (SOUNDBITE) (English) DANIEL GOLDMAN, ASSISTANT PROFESSOR OF PHYSICS, GEORGIA TECH, SAYING: "The lizards that we study, for example, can run, they are about 10 centimetres long, 15 centimetres long, they can run 40-80 body lengths per second so escaping from you in the desert in a blink of an eye." At that speed, the study of lizard locomotion can be difficult. So the researchers came up with the Sandbot, a machine that will run the same experiment countless times. (SOUNDBITE) (English) DANIEL GOLDMAN, ASSISTANT PROFESSOR OF PHYSICS, GEORGIA TECH, SAYING: "We use high speed video to really in detail record what the feet and body motions are as the animals and robots move around in these materials. And finally since we don't have the type of physics models for robot feet interacting with sand like we do for robot feet or airplane wings interacting with fluids we end up having to create some new physics models of these interactions. " These models take the form of computer simulations that Goldman says are the first step in understanding how lizards move so well in sand. Goldman hopes his models will allow future engineers to develop robots that are better equipped to handle rugged terrain with the speed and grace of a lizard.