https://phys.org/news/2018-05-smart-material-enables-applications-autonomous.html

Liquid crystal shells, only fractions of a millimeter in size, can easily be applied to surfaces, and have several unique properties that could be applied in engineering. As they reflect light highly selectively, they can be arranged into patterns that are readable for machines, akin to a QR code, adding coded information to objects. "These patterns could be used to guide autonomous vehicles or to instruct robots when handling workpieces in a factory. This could become important especially in indoors applications where GPS devices don't work," Prof Lagerwall explains.

The shells can be manufactured to reflect only certain wavelengths of light, such as infrared, that would be invisible to the human eye. As the liquid crystal shells reflect light "omnidirectionally," meaning that viewers see the same pattern regardless of their position and viewing angle, the patterns can even be read by moving objects. Additionally, the shells can be manufactured in a way that they change their structure when they are exposed to certain external impacts, such as pressure, heat or specific chemicals.