I don't think you could practically power a display + processor combo with the heat from your hands. The best I can find on the power radiated by your hands is

I don't think you could practically power a display + processor combo with the heat from your hands. The best I can find on the power radiated by your hands is this article https://www.smithsonianmag.com/innovation/this-flashlight-is-powered-by-the-touch-of-your-hand-180950226/ 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.