If you only think that the wheels are round, you will limit yourself to the truly wider world of quirky designs. [wadevag] Have been trying some of these concepts and successfully built an amphibious robot platform using star wheels Made of pool noodles.
This concept is similar to whegs. The combination of wheels and legs, they are actually a kind of leg that can rotate. Essentially, the stars on the wheels are like legs, pushing the robot one by one, instead of continuously contacting the ground like a typical round wheel.
The floating effect provided by the foam allows the robots to sit on the water easily, and the star shape allows them to act as viable paddles. This may be their main advantage. A round wheel will not provide any close forward propulsion.
[wadevag] Demonstrated the ability of the concept on water, concrete and snow, and handled all of them ingeniously. What is impressive is that it can get in and out of the water on its own strength. Although this may not be a viable solution for very heavy robots, it can work wonders for lightweight designs. This is not the first time we have seen some weird wheel designs. Video after the break.