Carter Hurd is robotics enthusiast who developed this transformable 3d printed wheel that can go across different terrains and surface textures. It has a smooth side and transforms into spiked configuration when it needs more traction and grip.
Hopefully Carter will open source the design ...
Update: Carter replied to me that he will publish the design files and paper on the wheel soon on his homepage ... Thnx Carter!
Here is a video of earlier prototype:
Project homepage with many more cool robotics projects:
The wheel is updated, the new transformative design makes it even more capable of trversing various obstacles.