I made a thing!
In 2014, I was holding a stack of iPhones and thought to myself:
"Hey, if I had each phone display a playing card, I could click a button and they'd shuffle themselves"
I pared that idea all the way down to this: trading cards made of e-ink displays.
Right now, each card costs me about $20 each, but with only a bit more scale, I think I can get that down to $10.
In doing this project, I learned how to design electronics and circuit boards. I learned Rust and wrote my first driver, I upped my CAD skills, 3D printed, and did my first resin casting. I generated the images on the cards using stable-diffusion.
HN always seems to appreciate new uses for e-ink. Thought I'd share :)
If you're thinking of mass-production might be worth reaching out to one of those manufacturers; you can buy in bulk if nothing else (but I'm sure they'd be open to customizing it a bit - maybe some branding on the plastic molding and whatnot).