In the Fall of 2010 I was on a 4-person team that designed a toy for 4th graders. The design was inspired by a type of sea urchin called a collector urchin. Our toy is a remote controlled sphere that drives around somewhat like an RC car, but can roll in any direction. It is powered by two contiguous rotation servos that move a weighted pendulum inside the sphere. As the pendulum is driven forward, the ball rolls forward due to gravity. The pendulum can be moved side-to-side to tilt the ball and make tight turns. A removable shell covered with sponges lets you paint abstract art using the ball and a remote control.