Auguste Rodin’s The Thinker is surprisingly light – but then again, the version I’m holding in my hand is only three inches tall.
And it’s not made of stone.
In fact, it was made in front of me on a 3D ‘printer’ at the Science Museum in London.
First, instead of ink, a thin coil of plastic wire was fed into a Ultimaker machine, then heated to 210C.
Once molten, it was squeezed out of a fine nozzle in flat layers just 0.6mm thick, gradually creating a version of the famous sculpture.
Printing the three-inch model, layer by layer by layer, took two hours at ‘high resolution’, although you could go faster on an industrial machine, or if you were prepared to accept a lower-quality figurine.
The finished Thinker feels rough to the touch – the result of all those tiny strata – but overall it’s an astonishingly accurate rendition of the masterpiece.
There is only one major limitation, according to Maël Lilensten of the museum’s 3D Print Show: ‘It can only print from the bottom up.’
That means the underside of The Thinker’s hand, with nothing to support it, has gone a bit dribbly.
Watching a three-dimensional object appearing out of thin air feels a bit like magic, so it’s easy to see why the scientific world is so excited about 3D printing.
The basic technology has been around for decades, but in 2014 a milestone was reached: the first 3D printers suitable for home use went on sale.
At £1,195 for the Cubify Cube and £699.99 for the Velleman K8200 they weren’t cheap; four years later in 2018 they are decidedly more affordable, at £219 for an Anycubic 3D printer kit on Amazon, for example.
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Experts hope that making 3D printing widely accessible will encourage even more innovation, as happened with home computers in the Seventies.
They foresee a future with a 3D printer in every home, and a shop with an industrial model in every neighbourhood.
Science Museum curators were so excited by the potential of 3D printing that in 2014 they launched an exhibition devoted to the technology.
‘At this stage the possibilities seem endless,’ wrote the museum’s Director of External Affairs, Roger Highfield. ‘Do I believe the hype? I do – but I am not so sure when the revolution will come.’
But let’s rewind: what exactly is everyone getting so enthused about? Put simply, a 3D printer allows you to download a blueprint for a three-dimensional object, then create an exact replica from plastic, paper or metal.
This is technically known as ‘additive manufacturing’, because you are building objects from scratch, whereas traditional manufacturing is often ‘subtractive’ – you take a block of stone, or a rough metal rod, and mill or grind it down into the finished version.
What can you make with a 3D printer? Almost anything, including, in the case of the RepRap, another 3D printer (admittedly, a human still has to assemble the parts).
Last summer, NASA successfully tested a printed rocket-engine part, and its European counterpart ESA is now working on spaceship components made from metal powder solidified by a laser beam.
At the other end of the scale, 3D printing has been embraced by hundreds of small-scale researchers and entrepreneurs, such as 23-year-old Joel Gibbard, who built a prototype prosthetic hand in his bedroom in Bristol. He thinks it could help those in the developing world who can’t afford a traditional prosthetic.
In the fashion field, 3D printing has been used to make flamboyant clothes and shoes. Finnish designer Janne Kyttanen launched a range of plastic wedge heels you could print out at home, and burlesque dancer Dita Von Teese modelled a dress printed from nylon mesh – not exactly the type of thing you would pop to the shops in.
Meanwhile, in the food industry, companies can now print decorations and delicacies using melted chocolate. If you fancy having a go yourself – maybe you need a secret weapon for next year’s Great British Bake Off? – Choc Edge will also sell you your own 3D chocolate printer which uses ordinary chocolate.
To clean your teeth afterwards, buy a personalised toothbrush from Blizzident in the US. It looks like a mouthguard filled with bristles, and it is custom-made in plastic using an impression of your teeth taken by a dentist.
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A miracle for medicine
It’s hard to name a part of everyday life that a 3D printing revolution would leave untouched, but perhaps the area where it could have the greatest effect is medicine.
Several laboratories around the world have developed the ability to print using stem cells or other living tissue as their ‘ink’.
A team at Hangzhou Dianzi University in China proudly showed off a dish full of ears in 2014, while in 2012 an 83-year-old Belgian woman received a jawbone printed from titanium after hers was destroyed by an infection.
Scientists are now working on growing whole organs. What is ground-breaking about body parts made this way is the element of personalisation: they can use your own cells, and can be tailored exactly to your physiology. Conventional orthopaedic surgery is often compared to carpentry, but with 3D-printed body parts, you get a perfect fit every time.
At the Science Museum, I spoke to Professor John Hunt of the University of Liverpool, whose team contributed a 3D-printed bladder to the exhibition.
The technique involves making a biodegradable scaffold, then growing the patient’s own cells over it for two weeks, before implanting it into the body.
This technique is a huge improvement on the current best option for a replacement bladder – using a section of intestine – which can lead to kidney stones and an increased risk of cancer.
And because doctors are using the patient’s own cells, there is minimal risk of rejection.
The research has turned Professor Hunt into an evangelist for 3D printing: ‘This keeps me awake at night. It’s a regenerative approach, meaning that it takes a fortnight to grow the cells, you have the operation – and then you might never need to treat the patient again.’
He believes that once the procedure becomes routine, the costs will come down drastically from £500,000 a time (compare that with the cost today of a hip replacement at about £50,000) and the NHS will embrace it.
A 3Dark side
As with all new technologies, though, there is also a dark side.
An enterprising criminal could potentially print a replica of your house keys from a high-resolution photograph, or create copies of your fingerprints from impressions left on a glass or screen.
In 2013 an American company called Defense Distributed released the blueprint for a single-shot plastic gun, The Liberator. It was downloaded more than 100,000 times before the US Department of Defense demanded it be withdrawn – though the plans since popped up on e-sharing websites.
Such ‘wiki weapons’ could become common – and because they are primarily made of plastic, they are difficult to detect.
But we need not worry just yet, because the Liberator on show at the Science Museum was little more than a pile of shattered parts: it disintegrated on firing.
Back at the Science Museum, I watch the next figurine start to come out of the Ultimaker. Something has gone awry with the way the new layers line up with the base, and Maël Lilensten aborts the job.
In the next decade or two, 3D printing could revolutionise medicine, manufacturing, design and even security – but the technology of the future still has kinks to iron out in the present.
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