Some foods and medicines, such as many COVID-19 vaccines, must be kept cold. As a step toward a robust, stable technique that could indicate when these products exceed safe limits, researchers in ACS Nano report a class of brilliantly colored microcrystals in materials that become colorless over a wide range of temperatures and response times. As a proof of concept, the team packaged the color-changing materials into a vial lid and QR code.
Click here for original story, Color-changing material indicates when medications get too warm
Source: Phys.org