A Paper by Jason Crawford
We have already come quite far in our mastery of materials and manufacturing. Our materials have gotten stronger: the tensile strength of stone, or of wood perpendicular to the grain, is on the order of 10 MPa (megapascals, a unit of pressure or stress); classical metals such as bronze and iron are in the low 100s; the best alloys of steel today are over 1,000 MPa.⁵³ We have also improved precision: James Watt struggled with leakage from his steam engines until, using the best technology of his day, they could be made to tolerances of 1/10 of an inch; now you can buy ball bearings made to a tolerance of 80 nanometers, an improvement of over five orders of magnitude.⁵⁴
There is an ultimate limit to precision: the atomic level. Making things by placing each atom exactly where we want it is a technological dream known as atomically precise manufacturing, or nanotechnology.
With nanotech, machine parts such as gears or bearings could be individual molecules, made from many atoms in exact configuration. A nanomachine such as a pump or engine, made from many such parts, might be the size of a large molecule such as a protein. A more complex machine, such as a robot, might be around the size of a cell.
- Storrs Hall paints the possibilities for this technological platform in his book Nanofuture. Macroscopic objects, from clothing to buildings, might be made with nano-machines built into them, in incredible numbers. Objects might be able to shape-shift: a telescoping arm, for instance, made up of 6,000 concentric cylinders each an inch long and 5 microns thick, could extend to a length of 50 feet or retract into a 1-inch puck.⁵⁵ With nano-motors integrated throughout, that arm and other parts like it might appear to move on their own, “like animals.”⁵⁶ Other nano-parts might give objects unique optical properties, or integrate large amounts of data storage and computing power into everyday items such as clothing.
What this enables for end users is straight out of science fiction. Nanotech synthesizers might make items directly from raw materials. A household synthesizer, like the “matter compiler” from Neal Stephenson’s Diamond Age, might create goods when they were needed; they might then be recycled afterwards for their atoms to be reused in a different configuration—no need for storage or cleaning.⁵⁷ Food, too, might be synthesized directly, with no animals or crops raised for the purpose, and with better taste and nutrition.⁵⁸ Thread might be made extremely strong, allowing clothing to be extremely light and flexible, like silk but much more so.⁵⁹
The incredible speed of nanotech synthesis alone might dramatically lower the price of literally every physical product. Hall estimates that with mature nanotechnology, the entire capital stock of the US—“every single building, factory, highway, railroad, bridge, airplane, train, automobile, truck, and ship”—could be rebuilt in a week.⁶⁰
The possibilities for medicine are also amazing. Surgery might no longer be invasive: a thread no wider than a hair might inject an army of nanobots into the patient’s body to reconstruct tissue, avoiding all of that messy cutting and sewing and the recovery time needed for wounds to heal: “There is no reason in principle that you couldn’t have major surgery one day and play tennis, go dancing, or do a full day’s work the next.” Artificial organs might replace diseased ones and even work better than the originals. Artificial red blood cells might transport oxygen more efficiently and store enough to allow you to hold your breath all day, or more practically, to survive a heart attack. Artificial immune cells might be able to fight pathogens more efficiently, giving you resistance against all infectious disease. Other nanobots might detect and destroy cancer, clean up accumulated toxins and other cellular “garbage,” and fix other kinds of damage to cells and tissues.⁶¹
At the macro scale, it turns out that the ultimate in precision manufacturing might give us the ultimate in material strength as well. One of the strongest ways to construct things from atoms is to build a lattice of carbon, which conveniently has four covalent bonds that suit it well for such structures. Graphene, a two-dimensional honeycomb of carbon, has tensile strength over 100 GPa (if free of defects), or two hundred times that of a typical steel.⁶²
Stronger materials might enable larger structures. Hall has proposed that with nanotech materials, we might build a “space pier,” a set of towers 100 km tall with a 300 km runway atop them. Payloads going to space might take an elevator to the top, then be accelerated along the ramp by an electromagnetic motor, saving much of the fuel required to launch from the ground; launch costs might get as low as $10/kg.⁶³
Diamond, with its extreme stiffness, might also be used to create very small, light structures. Hall has also proposed the “Weather Machine,” a fleet of quintillions of centimeter-sized balloons floating in the stratosphere. They could be made of nanometer-thick diamond, with remote-controlled mirrors that can reflect light or allow it to pass through, forming a “programmable greenhouse gas” that can regulate temperature and direct solar energy.⁶⁴
If there is indeed a fifth economic era, a successor to the “intelligence age,” it might be based on nanotechnology.