Nanotechnology: The “Top‐Down” and “Bottom‐Up” Approaches

Abstract Nanotechnology has grown at an enormous rate for the past three decades, and recent advances in nanostructured materials and nanodevices have opened up new opportunities in a variety of applications, ranging from information and communication technology to healthcare and medicine. Herein, an overview of nanotechnology is given, describing the origins of the field, present technology, ongoing research, and future aspirations. In addition, the two possible methodologies of fabrication—the top‐down and bottom‐up approaches—are discussed, covering the merits and drawbacks of each approach. As an example of a top‐down procedure, the fabrication of electronic integrated circuits and the foreseen limitations of the procedure for further miniaturization are described. The bottom‐up approach, through self‐assembly and supramolecular chemistry, provides an exciting alternative route either combined with the top‐down approach or on its own.