Animal insights into walking on sand

Researchers from the Georgia Institute of Technology have tested how lizards, crabs and robots cope with ground that is more or less "fluid" - by puffing air upwards through a box of sand.

By adjusting the flow of air, they control the stability of the surface with great precision.

The team describes the contraption as an equivalent to a wind tunnel, built for studying movement on unstable surfaces instead of aerodynamics and flight.

Tests of this kind could help design robots that can handle inconsistent terrain - such as might be found on Mars.

(Footage: Qian et al., Bioinspiration & Biomechanics, 2015)