This entry in the Red Bull Creation contest uses a laser to charge up a glow-in-the-dark message board. The concept is something we’ve seen several times before. Since light can excite a phosphorescent surface, moving pixels of light over that surface leaves a fading trail. Most recently we saw a spinning ring message board. This contest entry is different in that the board is stationary and the print head moves.
It’s basically a two-wheeled robot with a laser diode which can swivel perpendicular to the direction of travel. In this way, the laser prints the rows, and the motion of the robot takes care of advancing the columns. Since laser light has incredible intensity it is able to excite the phosphors much more thoroughly than LEDs. So the message will last longer than that spinning ring project or this awesome turntable hack. Don’t miss the video after the break that shows off the hack along with a bag full of theatrics.