Sisyphus is a kinetic art coffee table that uses a marble that automatically rolls to draw intricate designs on a layer of sand. The artist behind this table is Bruce Shapiro. The table works because under the table is a two-motor robot (the “Sisbot”) that moves a magnet which draws a steel ball through the sand. The motors are controlled by a small Raspberry Pi computer which plays a set of path files, that allows the design in the sand to change.
Bruce Shapiro – Sisyphus (youtube)