When two or more 2D materials are placed on top of each other their properties change and a material with novel hybrid properties emerges. These materials are called van der Waals heterostructures. By stacking free-standing membranes under observation in an electron microscope, researchers have demonstrated almost arbitrary 3D structures by stacking atomically thin materials, similar to a 3D printing process, where each atomic layer can be chosen from the vast library of available 2D ...
