Nanoengineering is the field of engineering which focuses on nanoscale. It studies the development and refinement of nanomaterials. It is considered as a practical application of nanoscience, because it does not emphasize on pure science aspects. Examples of nanomaterials include nanocomposites, nanotubes and quantum dots. It also deals with how various nanomaterials interact to make useful structures, systems, devices and materials. There are various techniques used in nanoengineering. They are molecular self-assembly and scanning tunneling microscope. Scanning tunneling microscope is an instrument, which is helpful in imaging surfaces at atomic levels