Nanotechnological systems are created using a variety of techniques. Two primary approaches are bottom-up and top-down fabrication. The bottom-up approach assembles structures atom-by-atom or molecule-by-molecule, often using chemical synthesis. The top-down approach involves cutting down larger pieces of material into nanoscale structures using methods like lithography and etching. Advanced techniques such as self-assembly and molecular beam epitaxy are also employed to create complex nanostructures.
