Maybe epaper price tags are suitable. Not a badge, but maybe a start: https://hackaday.com/2022/08/05/e-paper-price-tags-combined-to-create-a-large-wireless-d

Maybe epaper price tags are suitable. Not a badge, but maybe a start: https://hackaday.com/2022/08/05/e-paper-price-tags-combined-to-create-a-large-wireless-display/ https://hackaday.com/2022/08/05/e-paper-price-tags-combined-... Edit: more resources https://hackaday.com/2022/08/04/liberated-e-ink-shelf-labels-turned-10x2-display/ https://hackaday.com/2022/08/04/liberated-e-ink-shelf-labels... https://hackaday.com/2019/02/25/e-ink-price-tags-fall-off-store-shelves-onto-your-workbench/ https://hackaday.com/2019/02/25/e-ink-price-tags-fall-off-st...