@United has new coach trays that are coated with a material that has an amazing coefficient of friction. They are not sticky at all—there’s no adhesion effect—it is all friction. Even low surface energy plastics don’t slide on it at all.
The approximately 75-80° angle in the picture is the point at which the cup topples over itself. It isn’t adhered to the surface and it doesn’t appear to slide at all before toppling.
This would be the perfect coating for a smart phone pad in a car. I never managed to find out who made it.
No hot coffee on lap. :-)