This unique electromechanical clock is like a cross between a Magna Doodle and an Etch-a-Sketch.
Using a modified Magna Doodle as the basis for their display, the Clock-a-Doodle-Doo is the brainchild of a recent UCLA mechanical engineering class.
The clock uses a XY plotter-like mechanism to “draw” the current time by neatly arranging the magnetic particles with a mechanical pen. When it’s ready to change time, another mechanism pulls the “eraser” mechanism to release the particles and clear the magnetophoretic display. Each minute, it does the whole thing all over again. Lather, rinse, repeat.
Ever wonder how a Magna Doodle really works? HowStuffWorks has deconstructed the gory innards of the mysterious magnetic device for your personal enrichment.