This article's throwaway notion of glow-in-the-dark pins has got me thinking about how to make a surface with
light-up LED pins that can be stuck in arbitrarily.
- You could use (cleverly-braided+insulated) regular LEDs if there was a breadboard or something behind the map, but that'd be both huge and inconvenient.
- Maybe LEDs with inductive coils and a large backing induction mat?
- Given a metallic backing, and a regular fridge-magnet-like magnet, is there some way to trade some of the magnetic force the magnet is exerting on the backing for electrical power? Or maybe power a light using the normal force of the backing on the magnet. Either way, this would probably have the side-effect of reducing the coercivity in a regular permanent magnet way faster than otherwise. (You can make the whole backing surface a weak electromagnet, though! I wonder if that's more or less energy-intensive than making an induction mat of that size...)
- Maybe ignore conductive power, and try for radio power? RFID-powered LEDs? Crystal-radio-like LEDs? Or even just phosphorous-coated pinheads (not the matchstick kind; the CRT kind) with an infrared lamp or blacklight on the other wall?
- Or maybe, if you don't care about the LEDs only lighting up when on the wall, you could just make them "permanently" lit in the same way some exit signs are: put a tiny little bit of something radioactive in there, and then surround that with fluorescent gas in a glass shell.
- A chemical solution would be very interesting for its own sake. If there was potentially chemoluminescent fluid in the backplane (which would then have to be a gel/sponge), and the pins could pull it in via capillary action somehow—maybe the heads on the pins could be squeezed, making them effectively into little bulb syringes—then fluid could end up in the pinhead and react with something inside.
