Unmanned Systems Technology 025 | iXblue DriX I Maintenance I UGVs I IDEX 2019 I Planck Aero Shearwater I Sky Power hybrid system I Delph Dynamics RH4 I GCSs I StreetDrone Twizy I Oceanology Americas 2019

98 PS | Atomically precise manufacturing L ate in 2017, it emerged that the US military wanted the capability to create UAVs on demand in the field using 3D printing (writes Peter Donaldson). While remarkable in itself, this could foreshadow something far more significant if the technology of atomically precise manufacturing (APM) described by the ‘father of nanotechnology’” K Eric Drexler* comes to fruition. In concept, APM is about building complex products atom by atom more quickly and far cheaper than is possible with current manufacturing technologies. It starts with cheap and plentiful raw materials such as carbon and silicon, and cascades up through multiple scales of ever-larger sub- assemblies and finally to macro-scale products. Because the manufacturing would potentially be flawless, Drexler argues, the performance of machines made in this way would be far beyond anything possible at the moment. Nature already does something directly comparable at the heart of living cells, using molecular machines called ribosomes to assemble proteins from precursor molecules according to instructions encoded in DNA. We already have that kind of capability in chemical engineering and non- optical microscopy. Here, sequences of reactions are used to create atomically precise chemical end-products, and individual atoms can be manipulated using instruments such as scanning tunnelling and atomic force microscopes. IBM scientist Don Eigler did just that in 1989 when he arranged 35 xenon atoms to form the company’s initials. Drexler argues that potential APM technologies rest on well-understood scientific and engineering principles, although it will require advances in fabrication techniques. For example, ways have to be found of physically constraining the thermal movements of atoms to guide them to bond only with their intended partners to form nanoscale building blocks to build larger structures. The same constraining techniques, which are yet to be developed, would also be used to assemble components such as gears, bearings, cranks and levers that can then be brought together to form nanoscale versions of familiar machines such as motors, conveyors and pick-and-place arms. Processes that happen at very small scales also happen very quickly. While macro-scale final assembly would operate at the same speed as, for example, a modern car plant, a person watching progressively earlier stages would soon find that they look blurred. The scaling process would also mean that an entire ‘factory’ capable of taking in raw materials and producing finished vehicles only needs to be about the size of box big enough to contain the final assembly stage. For a small quadcopter for example it would therefore easily fit into the back of a typical 4x4. Drexler argues that fragmented and unfocused development has held APM back to date, likening the effort required to make it a reality to the one behind the Apollo Moon shot, which was ultimately a gargantuan exercise in engineering management. APM is the ultimate in additive manufacturing, and for the world of unmanned systems and far beyond it promises change no less revolutionary than the agricultural, industrial and information revolutions. * Drexler, K. E., “Radical Abundance: How a Revolution in Nanotechnology Will Change Civilisation”, PublicAffairs, ISBN 9-7816-1039-1139 Now, here’s a thing “ ” The scaling process means a ‘factory’ for making a small quadcopter for example would easily fit into the back of a 4x4 April/May 2019 | Unmanned Systems Technology