An interesting homemade display takes a different path than usual with surprisingly good results.
When it comes to building a display at home, you're typically limited to either a mechanical display or a matrix of lights. While it is theoretically possible to get to smaller scales, the equipment and technology needed to make something like an OLED or LCD aren't likely to be found in your garage.
Marin Davide had a really interesting idea on how to create a visually appealing display of a different kind. Instead of going mechanical or with a matrix of LEDs, the display of choice was a curved plate of thermochromic material.
The curved display in action
Looking at that image should give you a pretty immediate feeling for how this display looks. Bits of nichrome wire are mounted on the back of a material covered in thermochromic paint. When the nichrome wire heats up, the material changes color. The result is this very organic and visually appealing. Not only does it look great, but it is fairly simple to reproduce. The only real drawback to this display is the fairly slow refresh time. You have to wait for the material to cool down for something to disappear.
When I read that the refresh rate was slow a thought popped into my head on how to possibly speed it up. Could a micro-miniature solenoid valve be used to dispense cold spray to the rear of the display? The -60F cold spray should take only milliseconds to essentially "erase" the heat generated character.
The valve could be controlled by the Arduino that's driving the heating coils, and with a little adjustment to direction, spread, and duration it may be able to dispense the cold spray so that the "erase" mode gets to be very precise as far as timing and perhaps even location is concerned.
@Templar...good idea, but that needs consumables - bad news. You might be able to just use compressed air though. I was thinking miniature peltier modules - use a lot of them to make segments or a dot matrix. Depending how you drive them they will heat or cool. You'd probably only have to cool temporarily to erase, but to display you'd have to keep current flowing - but then you do at the moment with the NiChrome wire.
I doubt this will be a game-changing display technology but it could take off for aesthetic reasons - it is quite pretty....
HI Caleb. Yeah, I don't think it would be worth the effort either. Peltier might be worth a try but I don't know if you can get them that small. Thinks - since the thermochromic stuff does different colours, maybe you could make a colour dispolay by using different drive levels.....
CRT, LCD, Plasma, LED, OLED ... new ideas have to start somewhere; a good effort. The material used in this prototype has bulk characteristics and the slow refresh rate is expected. A little materials science and a new thermochromic formula might result in a nano-particle material that will respond faster to changes in applied thermal energy.
The video is pretty amateurish and does not do this great idea justice. Use a tripod to keep the camera still, and sort out your lighting to minimise reflections (with a curved surface like this, use side lighting). And show us how fast it can change.