A snail might not necessarily be your first choice when it comes to mobile robot design, but our gastropodal friends have a few tricks up their non-sleeves when it comes to moving themselves around. Most snails rely on two techniques to move: undulating, which uses fluidic mucus pressure, and galloping, which is apparently when "like an inchworm, the animal sticks the front of its foot to a surface (thanks to suction and friction from the mucus), and then draws the rest of its body up behind it.”
This galloping technique has been adapted (and expanded) for robots by the Biomechatronics Lab at Chuo University in Japan. Their "Snail-Wave Omnidirectional Mobile Robot," Toro II, may not look a whole lot like a snail (and it's completely mucus free), but check out its moves:
The advantage of this robot with its sexy wave action is stable omnidirectionality: no matter what direction it's moving in (and even if it's not moving and/or completely powered off), the robot boasts a large and grippy area that's always in contact with the ground. You can compare this to other omnidirectional robots, such as the slug bots, squishy creatures that transform from soft to hard, or the Mecanum wheel system, which offers varying resistance depending on what direction it's moving and requires active braking if it needs to stay in one place. The snail robot, by contrast, is much more resilient to things like unintended shoves, and its designers suggest that this inherent stability and freedom of movement might make robots like these ideal for hospitals and factories.
[ Nakamura Lab ]