Universal Gripper Robotic Feet

Imagine you've built a walking robot, and it moves reasonably well on a flat, smooth, high-traction surface... but it slides around on overly polished floors, and has trouble when the terrain is overly sloped or even if parts of the terrain are overly sloped.

Now, suppose we replace each of the feet (or perhaps just the bottoms of the feet) of the robot with a type of device called a Universal Gripper, and whenever the foot makes contact with the ground, actuate the gripper, and whenever the foot is about to be lifted up, release the gripper... or even apply positive pressure with the gripper, so that it pushes away from the ground.

Now, you're probably going to ask, "what in the world is a Universal Gripper?" It's an amazingly simple device: a rubber balloon, filled with granules, with a mechanism to suck out air from the balloon (which makes it rigid) and a valve to release air back into the balloon (which makes it soft). The more advanced version also has a mechanism to quickly blow air into the balloon, to toss away whatever had been held... or in this idea, push away from the ground a bit faster.

The Universal Gripper was invented in 2010, and has become relatively well known (if you google search for "universal robotic gripper", you'll get over 100,000 results), spread from the time of it's invention, till the present.

After it occurred to me that this kind of gripper would make awesome robotic feet (while watching a video of a walking robot whose feet were sliding around), I searched Google, and found precisely /one/ relevant result -- a one line mention, shortly after the Universal Gripper was invented. So it's not baked or half-baked, and certainly not /widely/ known to exist.