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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
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
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.
||you need to shape them differently.
||1: Add re-growable or replaceable hairs to take
advantage of van-der-waals.
||2: Shape so they deflate from outside to inside
and make (adjustable-depth?) cups when fully
deflated, creating suction cups
||3, possibly: Add a band around (inside) where the
rim of the cups will be, capable of sliding against
itself to shrink or grow. This will let the cups
physically grab on to any protrusions should that
be helpful, or press against the sides of cracks and
holes in the surface.
||4, possibly: rough spikes that can stick out of the
middle of the pad to obtain a better grip in gels,
muds, and flesh.
||//filled with granules//
IIRC, the early versions used coffee grounds. Good complex surfaces for the particles to grab each other (during the "suck for rigidity" phase).
(PS: "suck for rigidity" innuendo was entirely unintentional...)
||The universal gripper is dependent on the
particulate forming a surface that clamps down on
irregularities in the gripped object.
||It won't work all that well on smooth surfaces
(polished marble, glass, etc.).
||Given the need for an extremely pliable outer
surface, it will also be somewhat vulnerable to
damage from rough/sharp surfaces. A rubberized
kevlar or similar might avoid that problem,