Hwang Sung Hyun has designed power-generating electric Energy Balls using piezoelectric materials that convert mechanical signals into electrical signals or electrical signals into mechanical ones. Simply playing with the energy ball will generate electric power and collect it inside the ball. The stored electricity can power a light bulb.
The power-generating electric Energy Ball would allow children, especially those in the third world, to play and power a reading light at night. The design was a red dot design award winner in 2009.