The phrase "flat substrate" refers to a smooth and level surface on which something can be placed, attached, or built upon. It is a plain and even base that provides stability and support for other objects or materials. Full definition
For the past decade, scientists have made metamaterials that work at microwave, infrared and visible wavelengths by fabricating repeating metallic patterns on flat substrates. (sciencedaily.com)
However, in vitro experiments dealing with epithelia are mostly performed on flat substrates, neglecting this out - of - plane component. (science.institut-curie.org)
«Unlike exfoliation and chemical vapor deposition methods, which normally produce relatively thick perovskite plates, we were able to grow uniform square - shaped 2D crystals on a flat substrate with high yield and excellent reproducibility,» says Dou. (sciencedaily.com)