Over on Adafruit, John Edgar Park latest project lights up the Halloween gloom with a rack of glowing test tubes illuminated by computer-controlled LEDs and florescent UV pigment. John writes of the project:
A proper mad science laboratory requires mysterious potion-filled test tubes lit with eerie colors to flicker in their rack. Build this display for maximum creepy effect!
Flourescent pigments mixed with water make for a creepy-cool luminescent potion when lit with ultraviolet light, especially as they flicker and blink based on a microcontroller pattern you design. You can use this technique to make test tubes glow in a standard test tube rack, or build your own from black iron pipe fittings and laser-cut acrylic for some next level spookiness!
The system is powered by an Adafruit Feather development board driving 13 UV/UVA 400nm LEDs. Besides using the lights and electronics to illuminate a test tube rack, you could also use them to light beakers and other bubbling labware or other equipment and features of your mad scientist lair.
You could obviously just buy cheap test tube racks to display your creation, but John decided to build a suitably industrial-Gothic-looking rack out of black iron pipe and a test tube holder that he designed and 3D printed. The plans for the rack and the CAD file for cutting the tube holders are included on the project page.
See the full details of the build and get the control code on the Adafruit Learning System.