Electrochromic displays from Ynvisible are based screen-printable electrochromic polymers. The term ‘Electrochromism’ refers to the phenomenon whereby a material undergoes a physical color change in response to an electrical stimulus. Electrochromic displays are produced by printing thin layers of these materials with high-performance electrolytes into a flexible ‘electrochromic stack’. When a voltage is applied to the electrochromic material in the presence of the electrolyte, it undergoes chemical oxidation and reduction. These processes are associated with a color change which can be finely tuned. The final displays are as thin as 200 µm and flexible enough to curve around a pencil.
Read more here: https://www.ynvisible.com/news-inspiration/what-is-an-electrochromic-display