i just came up with the idea of physical digital post-it notes

they are just small e-ink screens with a magnet at the back you update via your computer

this way you can have a physical kanban board with the content from your digital one or issue tracker

but turns out, engineers at microsoft had the idea before

https://www.geek.com/tech/microsoft-creates-electronic-post-it-notes-that-never-need-charging-1676642/