Towards atomic and close-to-atomic scale manufacturing

Human beings have witnessed unprecedented developments since the 1760s using precision tools and manufacturing methods that have led to ever-increasing precision, from millimeter to micrometer, to single nanometer, and to atomic levels. The modes of manufacturing have also advanced from craft-based manufacturing in the Stone, Bronze, and Iron Ages to precisioncontrollable manufacturing using automatic machinery. In the past 30 years, since the invention of the scanning tunneling microscope, humans have become capable of manipulating single atoms, laying the groundwork for the coming era of atomic and close-to-atomic scale manufacturing (ACSM). Close-to-atomic scale manufacturing includes all necessary steps to convert raw materials, components, or parts into products designed to meet the user's specifications. The processes involved in ACSM are not only atomically precise but also remove, add, or transform work material at the atomic and close-to-atomic scales. This review discusses the history of the development of ACSM and the current state-of-the-art processes to achieve atomically precise and/or atomic-scale manufacturing. Existing and future applications of ACSM in quantum computing, molecular circuitry, and the life and material sciences are also described. To further develop ACSM, it is critical to understand the underlying mechanisms of atomic-scale and atomically precise manufacturing; develop functional devices, materials, and processes for ACSM; and promote high throughput manufacturing.