high-quality precision optical components
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. Researchers led by Prof. Fengzhou Fang from Tianjin University/University College Dublin have recently reviewed the development Atomic and Close to atomic Scale Manufacturing (ACSM) based on atomic level operation modes in subtractive, transformative, and additive manufacturing processes. Fang has formally proposed three phases of manufacturing advances:
• Manufacturing I: Craft based manufacturing by hand, as in the Stone, Bronze, and Iron Ages, in which manufacturing precision is at the millimeter scale.
• Manufacturing II: Precision controllable manufacturing using machinery where the material removal, transformation, and addition scales are reduced from millimeters to micrometers and nanometers.
• Manufacturing III: Manufacturing objectives and processes directly focused on atoms, spanning the macro through the micro to the nanoscale where manufacturing is based on removal, transformation, and addition at the atomic scale, namely, atomic and close to atomic scale manufacturing.
In this review article, the authors systematically analysed literatures in area of subtractive manufacturing including ultra precision machining, high energy beam machining, atomic layer etching, atomic force microscope nanomachining, where atomic wide line was achieved by focused electron beam sculpture based on 2D materials, such as transition metal dichalcogenides. Sub nanometer finish can be achieved with ultra precision polishing and atomic layer etching, where defects free and single atomic layer removal are still not possible. Atomic scale additive manufacturing, featured with macromolecular assembly with feedstocks, such as DNAs, proteins and peptides, represents atomic precision manufacturing of biological machines. Atomic scale transformative manufacturing, such as using Scanning Tunnelling Microscopy, Atomic Force Microscopy and Scanning Transmission Microscopy, has demonstrated capability for operation of single atoms. They also summarized the metrology technologies for ACSM and current applications.
Today, the famous Moore’s law is approaching its physical limit. Computer microprocessors, such as the recently announced A12 Bionic chip and Kirlin 980, use a 7 nm manufacturing process with 6.9 billion transistors in a centimeter square chip. Such limits have been pushed to a 5 nm node and even a 3 nm node, which represents a few tens of atoms. Human beings are already stepping into the atomic era. Meanwhile, human society is facing unprecedented global challenges from depleting natural resources, pollution, climate change, clean water, and poverty.What shall we do? Such challenges are directly linked to the physical characteristics of our current technology base for producing energy and material products. According to the authors, it is the time to start changing both products and means of production via ACSM, which includes all of the steps necessary to convert raw materials, components, or parts into products designed to meet users' specifications. They believe research should focus on extensive study of fundamental mechanisms of ACSM, development of new functional devices, exploration of ACSM of extensive materials and amplifying throughput for future production.