Time–Temperature Integrating Optical Sensors Based on Gradient Colloidal Crystals (Adv. Mater. 40/2021)

Collodial Gradient Materials Colloidal gradient materials introduce local variation of the physical properties to well-established colloidal crystals. In article number 2101948, Markus Retsch and co-workers describe a method to fabricate such colloidal gradient materials. Using such structures as time–temperature integrating sensors is just one application that showcases the potential of this materials class.