Game of Knowns by Dr Karl Kruszelnicki – Extract

Game of Knowns


A few animals, such as apes and otters, use sticks and stones as tools. Even so, we humans classify ourselves as the Tool-Making Animal. Well, a little while ago we humans invented a new tool, and it seems it will revolutionise our manufacturing industries over the next few decades.

It can potentially make anything – a working clock, jewellery, vaccines, a metal axle for your car, toys, a tooth, a human organ, a violin, a hand gun, slightly different-sized shoes that fit your left and right feet perfectly, or a chain-mail vest with a zip down the back. It can even make an exact copy of itself.


This new tool is called, rather confusingly, a “3D Printer”.

But it does not print 3D pictures, the kind that spring to life when you look at them with special glasses. No, it fabricates actual three-dimensional objects, one thin layer at a time – and then builds up hundreds or thousands of these layers on top of each other until the object is completed.

So why did the process get called “3D Printing”?

Well, one popular type of regular paper printer is the inkjet printer. It prints onto paper by squirting out tiny balls of ink from tiny nozzles. These balls of ink are so little that it would take thousands of trillions of them to make up a litre.

Some of the early 3D Printers made their fabrications by squirting out tiny volumes of liquid from tiny nozzles, just like a regular printer. And, just like a regular printer, those 3D Printers were controlled by a computer that follows instructions from a file. (One website that you can download files from is called “Thingiverse – Digital Designs for Physical Objects”, and there are many others.) Engineers call this process Additive Layer Manufacturing, but the more popular name, 3D Printing, is the one we’ll probably be stuck with.


The first 3D Printers were called Rapid Prototyping Machines. They were used to make plastic prototypes of complex designs, because engineers wanted to see and hold a full-size model of what their final product would look like. Start-up companies and academics (many at the University of Texas at Austin) began making these machines in the late 1980s. For example, 3D Systems from South Carolina had their first commercially available Stereolithography machine in 1986.

Back then, a 3D Printer would deposit a thin layer of liquid resin and run a tiny ultraviolet beam over the surface in a specific pattern. The ultraviolet light would harden the resin in that pattern. The printer would put down another very thin layer, harden part of that, and keep on building it up. The unhardened resin would just drain away or be washed away. After several hours or days the final object, perhaps the size of a loaf of bread, would be ready. However, it would be made of a plastic resin, not the metal, wood or leather that the final manufactured object would be made of.

The other approach, also dating to the 1980s, was called Selective Laser Sintering. Powdered ceramic, metal or glass was laid out in a thin layer, and then melted and fused with a high-temperature laser. This would then be repeated, thin layer after thin layer, until the final object was made. (To make the laser’s job easier, the chamber would be heated to about 10°C below the melting point of the material.)


Since the 1980s, the field of 3D Printing, or Additive Layer Manufacturing, has advanced enormously.

For example, before Rapid Prototyping Machines, it used to cost Timberland US$1200 and take one week to hand-craft a sole for an upcoming shoe. Now it takes 90 minutes and costs US$35.

Today, there are many different types of 3D Printers.

Originally we were limited to using only liquids (plastics or resins) as the raw materials. Today, the raw materials that go into the Printers can be plastics (solid, liquid or granular), metals, ceramic powders, metal or plastic film, chocolate, icing sugar, silicone rubber, simple chemicals, concrete or paper. Even clothing has been Printed.

There are many different technologies to harden the raw material into the physical object – Ultraviolet Stereolithography, Selective Laser Sintering, Electron Beam Freeform Fabrication, Direct Metal Layer Sintering, Fused Deposition Modelling, and so on.

The precision of Printing is usually limited to around one-tenth of a millimetre (about 100 microns), but that will improve with time.

Besides the convenience, 3D Printing can reduce waste enormously. Most of the material extruded or laid down ends up in the final product. This is quite different from the manufacture of, say, a laptop computer. Currently, that process starts with a solid block of aluminium, and then 95 per cent is removed by machining to leave behind the case and the internal ribs.


In 2011, European Aeronautic Defence and Space Company (EADS), the company that makes the Airbus, Printed a bicycle using Selective Laser Sintering. The raw materials were metal, nylon and carbon- reinforced plastics, in the form of a fine powder – leading to wheels, wheel bearings, axles and a frame. As we develop the technology to manipulate these materials down at the level of molecules, we’ll be able to Print high-stress, safety-critical aviation components.

In 2012, British chemists Printed drugs. They first used a common bathroom sealing material to Print some Reaction Chambers – basically miniature eggcups. Then they squirted standard chemicals, via a US$2000 3D Printer, into these mini eggcups, which when combined in a simple chemical reaction gave a drug. They are now working on Printing the common anti-inflammatory drug ibuprofen. They have already shown how easy it is to Print chemical laboratory equipment.

In 2013, the mobile phone company Nokia released 3D files of their flagship Lumia 820 handset so you can customise the case to suit yourself. You can have a waterproof, glow-in-the-dark phone with a built-in solar charger, corkscrew and bottle opener if that’s what you want.

Also in 2013, engineers at Oak Ridge National Laboratory in the USA Printed a 600 gram robotic hand. It integrated a metallic skeleton with a titanium skin-like mesh, and had hydraulic pipes running through the skeleton. Let me emphasise that there were no pipes, hoses or drilled holes – the hydraulic fluid that powered the robotic hand ran through Printed ducts in the structure. Voids were deliberately left as the robotic hand was printed, layer by layer. The hydraulic fluid runs at enormous pressures to power the hand – 2000 tonnes per square metre. 3D Printing is the only technology we have that can make a functioning robotic hand like this one. Even so, it took 24 hours to Print all the parts for this first hand, and another 16 hours to assemble it. The engineers are developing a 3D Printer to fabricate the entire hand in a single piece.

A gun was Printed for the first time in 2013, on a US$8000 3D Printer. First, the separate components were Printed in ABS plastic, and then they were assembled into a white plastic gun. The firing pin was a simple household metal nail. The gun survived only half a dozen firings before self-destructing – but with those firings, it could have delivered a lethal wound. Within a week, over 100,000 copies of the computer files needed to make that gun had been downloaded.

All of that said, the technology is still young. The 3D Printing process can take a long time, both the quality and the surface finish can be variable, and it’s still difficult to build complex objects from many different kinds of materials.


There are currently two major trends.

First, the technology has gone far beyond making plastic prototypes to making production runs of actual objects. For example, the giant aerospace company Boeing has printed some 22,000 parts for their jet planes, both military and civilian. Printed parts are used on both the F-18 Fighter Jet and the Boeing 787 Dreamliner Passenger Jet. Boeing’s rival, Airbus, is trialling Printed parts for control surfaces, cooling systems, and lighter-weight brackets and landing gear components.

In 2013, the world’s largest manufacturer, GE, announced they would use 3D Printing to make a fuel nozzle for their new LEAP jet engine. (They already have US$22 billion of confirmed orders for this LEAP engine.) 3D Printing would make obsolete the old production method of casting and then welding 20 small metal parts. Instead, the nozzles would enter life as a flat bed of cobalt-chromium powder. The plan is that a powerful laser would melt or fuse the powder in a layer, then another layer just 20 microns thick (0.2 millimetres) would be added. It would in turn be melted with the laser, and this process repeated until the final fuel nozzle was Printed. Each jet engine would use 10 to 20 nozzles, and the plan is to print 25,000 annually by 2016.

Second, the field has split.

At one end are the huge professional-grade 3D Printers that fill a warehouse. These are the ones used by the aerospace industry.

At the other end you can buy, for a few thousand dollars, an amateur-grade 3D Printer that can sit on a desktop. The cheap ones are currently basically a Toy, not a Factory. Slowly, and not very precisely, they will Print a plastic version of what you want.

But over time the price will come down, and the capability will go up.


The potential is enormous.

You could print off a metal gear to replace the broken one in your car’s gearbox, or some of that extra-special lubricant for your bike chain. In a sudden killer-flu epidemic, you could print off enough antiviral drugs for your whole family. You could use one 3D Printer to make another identical 3D Printer, and so on, and so on (and so on).

In artificial hip joints, there is a metal ball-and-socket. The inner part of the socket has to be really hard and impervious, so that it doesn’t wear. But the outer part, the section that binds to the bone, has to be porous, so that the bone will infiltrate and bind to it. The previous method was to make the socket from two different types of metal and then bond them together. However, with 3D Printing, you can make the socket from one piece of metal, just changing the porosity and density of the metal where it sits close to the bone.

Suppose we can have different materials in a single part. You could incorporate tracks that carry electricity or light, and even lots of sensors.

There will be social changes. At the moment, in the field of manufacturing, the countries that have the advantage are those with low costs and low wages. So manufacturing capacity may well shift around the world; although it’s much too early to make specific predictions, we know that Manufacturing Capability will shift, but not to where, nor in what quantities. Another claim is that there will be no need for factories when any town, village or even house can have its own 3D Printer. However, if you want to make hundreds of pencils each minute, there are advantages in using a big factory with assembly lines.

There will be legal changes. If a manufactured item can be totally described and specified with a digital file, then that digital file can be copied. Once it escapes from the original manufacturer, how will they get their royalty or cut?

We could send these machines to an asteroid, and they could use the raw materials of the asteroid to build a home for us for when we eventually move into space.

Maybe the 3D Printer will be as significant as the printing press in 1450, the steam engine in 1750 or the transistor in 1950.

I might be wrong, but I think it will be a Game Changer.

Excerpted from Game of Knowns by Dr Karl Kruszelnicki. Copyright © 2013 by Dr Karl Kruszelnicki.
All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.
Excerpts are provided by Pan Macmillan Australia solely for the personal use of visitors to this web site.


One thought on “Game of Knowns by Dr Karl Kruszelnicki – Extract

  1. Pingback: Half Size Human Skeleton Model | shareAsell.ORG

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