Imagine a flexible-skinned hollow ball.
Within the ball is an inner skeleton
consisting of a small solid ball with
pencil-thick spines sticking out of it and
connecting the inner skeleton with the
outer ball. Rather like a robustly
proportioned sea urchin trapped rather
too snugly unside
a volleyball.
The spines would be connected to
sensors
and linear motors. When a spine is
pushed in rapidly, for example by the
ball
being bounced on or near that spot, the
spine pushes out even more rapidly, then
returns to
its normal position. The result is that
when anything pushes quickly on the
ball, it is
pushed back hard and fast.
You turn the ball on and throw it into the
air. It lands, one or more of the spikes
activate, bouncing the ball higher into
the
air than you originally threw it. Some
random motion will also be imparted as
the
ball will not symmetrically have landed
on
the spines.
Ideally played with in a large sports-hall
with a low-ish ceiling to allow the ball to
bounce of not only the floor and walls
but
also the roof.
Release the ball then spend the next ten
minutes trying to catch it.
Not to be played near overhead power
cables, breakable objects or sudden
sharp
drops.