Using wide rubber bands wrapped around the last links, this robot
grips and twiddles a ball between its fingers. Each finger has three joints,
which can bend forward and backward.
![](fingers.gif)
Using balanced motions, the fingers can even roll the ball back and
forth while holding it steady in space, similar to the way a human can roll a
marble between thumb and forefinger.
At lower right, the ball is gripped from above, helped by the fingers'
rubber-band surfacing.