How plausible are animated versions of these in real life? What's the thinnest we can make a display+processor combo that can be powered by, say, the heat from my hands?
https://www.smithsonianmag.com/innovation/this-flashlight-is...
That article says you can get about 5 milliwatts using a Peltier converter, so working backwards based on Peltier converters being ~10% efficient that's only 50 milliwatts radiated by your hands. Even with an ideal 100% efficient converter that turns 100% of that energy into electricity, combined with a 100% efficient step up converter to raise the voltage that's not a lot to work with, that's barely enough power to light a couple of blue LEDs, much less a display and a microcontroller capable of rendering 3D graphics.