In this experiment, I show you how you can make thermal cards based on cholesteric liquid crystals. Cholesterol derivates can become a liquid only by slight heating, but when they change their aggregation state, they form so-called cholesteric liquid crystals which can interact with visible light and making such a colourful effect.
Music by: Meydän - <a rel="nofollow" class="external text" href="https://freemusicarchive.org/music/Meydan/For_Creators/Underwater_1569">Underwater</a> (CC BY 4.0)
<a href="//commons.wikimedia.org/wiki/User:Bilovitskiy" title="User:Bilovitskiy">Bilovitskiy</a>
CC BY 4.0
<span class="int-own-work" lang="en">Own work</span>