Chemical patterns can be created using several techniques:
1. Self-assembly: This is a process where molecules spontaneously form ordered structures without external guidance. Molecules like block copolymers can self-assemble into desired patterns due to their inherent chemical properties.
2. Lithography: This involves using a patterned mask to selectively expose parts of a substrate to light or electrons, which then undergo chemical changes. Techniques such as photolithography, electron-beam lithography, and nanoimprint lithography are commonly used.
3. Dip-pen nanolithography: A scanning probe technique where an atomic force microscope tip is used to "write" chemical patterns on a substrate by depositing molecules in a controlled manner.
4. Chemical vapor deposition: This process involves the deposition of gaseous reactants on a substrate, leading to the formation of a thin film with a desired chemical pattern.
