MARCH TO INSPIRE: Charles "Chuck" Hull: The Father Of 3D Printing Who Shaped Technology

Charles Hull knew his invention would take up to 30 years to find its way into people's homes. Today the possibilities appear endless

Although measured and deliberate in his responses, there is one moment when the softly spoken Chuck Hull – known as the father of 3D printing – tells of his surprise about what exactly his creation was capable of achieving.

In 1996, surgeons at the Wilford Hall medical centre in Texas working to separate a pair of conjoined twins thought that only one would be able to walk after the operation. After a model of the girls' bone structure was generated using 3D printing, however, they found a shared upper leg bone to be bigger than expected and split it successfully, resulting in both twins being able to walk.

Hull said: "This is extremely difficult for surgeons, to figure out how they are going to separate the two twins so that you will have two separately living people. When some of those surgeries were first done using the help of our technology, it was really touching for me."

Now 75 and still working as chief technology officer of 3D Systems, the company he co-founded, Hull is enjoying some minor celebrity 31 years after he first printed a small black eye-wash cup using a new method of manufacturing called stereolithography, now known as 3D printing.

At the time, he was working for a company that used UV light to put thin layers of plastic veneers on tabletops and furniture. Like others within the industry, he was frustrated that the production of small plastic parts for prototyping new product designs could take up to two months.

He had an idea that if he could place thousands of thin layers of plastic on top of each other and then etch their shape using light, he would be able to form three dimensional objects. After a year of tinkering with ideas in a backroom lab after hours, he developed a system where light was shone into a vat of photopolymer – a material which changes from liquid to plastic-like solid when light shines on it – and traces the shape of one level of the object. Subsequent layers are then printed until it is complete.

After patenting the invention in 1986, he set up 3D Systems in order to commercialize the new method of production and went on the road to secure both funding – eventually getting US$6m (£3.5m) from a Canadian investor – and customers, using videotapes to show the equipment. The first commercial product came out in 1988 and proved a hit among car manufacturers, in the aerospace sector and for companies designing medical equipment.

Soon General Motors and Mercedes-Benz were using 3D Systems' technology – the company sold printers, materials and software – to build prototypes, but it was developments in medicine that stunned him, such as when models in advance of surgery could be created. "That was just startling to me, that someone used the technology like that."

When Hull originally came up with his invention, he told his wife that it would take between 25 and 30 years before the technology would find its way into the home. That prediction proved correct as the realistic prospect of widespread commercial 3D printers has only emerged in recent years.

The possibilities appear endless – from home-printed food and pharmaceuticals to suggestions that pictures of ceramics will be able to be taken in shops and then recreated using plans downloaded from the internet.

Hull, an unassuming man who has 93 patents to his name in the US and 20 in Europe, says he is "humbled" by the possibilities but stops short of predicting what his technology could eventually deliver, although he is confident printers could soon be in every home.

"It's nice to get some recognition, it was a lot of hard work but other than that I just keep working," he said last week in Berlin, where he received a European Inventor Award.

Controversy has arisen with the possibility that guns will be able to be produced using 3D printing, again using blueprints downloaded from the internet. A group called Defense Distributed last year successfully tested a 3D printed gun in Texas. Hull said: "My first thought is that people messing with that – I hope they don't hurt themselves. Building and testing guns of that nature could be dangerous. I think the people doing that were trying to make a point.

"I don't know that people are going to be printing guns around the world but in any case our company, we are not the government or the police agencies. It is more their business and all technology, the governments and the police have to be aware [of], it is not just 3D printing."

After finding that retirement was not for him, Hull returned to the company he co-founded and is now vice-president as well as chief technology officer, and holds shares worth $20m (£12m). Last year, 3D Systems brought in revenues of more than $500m (£294m) and has three bases in the UK, in Hemel Hempstead, High Wycombe and Clevedon. New systems of 3D printing have emerged over the years and various other firms have been added to the 3D Systems stable.

In 2014, the company launched the Ekocycle Cube printer in a collaboration withthe singer Will.i.am, named chief creative officer in January, which is touted as being for everyday use and priced at US$1,199 (£705).

Stepping down is not an option at the moment for Hull, who declares the products of 3D printing, now including ranges of jewellery, as "all his children". Future projects include working with Google on the company's next generation phone.

"We always say which room is it going to be in? I am not much of a futurist. It is really difficult for me to project. I sit there and work on the projects I have and I don't have a lot of say on where this is going."

What can be printed?

On a small plot in the north of Amsterdam, architects are building what they hope will be the first 3D-printed house. They are laying blocks that have been printed using a scaled-up version of an open-source 3D printer to be stacked like Lego bricks – one of the more elaborate examples of what can be produced using 3D printing.

The recent Consumer Electronics Show in Las Vegas showcased printers that could produce foods such as ravioli and chocolate printed patterns, while Harvard researchers have recently unveiled what they say is the first 3D printed battery, which can be constructed in minutes.

'The Night I Invented 3D Printing'

Hull found retirement was not for him so he returned to 3D Systems and is now vice-president and chief technology officer.

Story highlights: Chuck Hull is the American engineer who invented 3D printing Hull created the first 3D printer in 1983 and has been refining his creation ever since He says the process has "blossomed" in the last few years

Call him Charlie, Charles, Chuck -- whatever you want. It's all okay with him.

Beaming a warm smile from beneath his push-broom mustache, the softly spoken 74-year-old doesn't strike you as a pioneering innovator -- the man responsible for a breakthrough that's now driving forward the world of manufacturing.

But Chuck Hull -- "in this kind of environment, it's usually 'Chuck'," he says, as he sits down with CNN in Frankfurt, Germany -- is executive vice president and chief technology officer of 3D Systems, a company built on his creation: the 3D printer.

In 1983, Hull was working for a small business that made tough coatings for tables using ultraviolet lamps. When he suggested a new way to use the UV technology -- to quickly turn computer designs into working prototypes -- Hull was given a little lab to play around in during his evenings and weekends.

Hull experimented for months, on his own with a plastic-y gloop -- then one night, something emerged...

CNN: When you began, what materials exactly were you using?

Hull: The class of materials is called "photopolymers" and these are typically acrylic-based materials that would be liquid until they're hit with -- let's say -- an ultraviolet light. Then, they instantly turn solid. So, you have a vat of this liquid and a point of ultraviolet light, and you turn it into a solid piece of plastic. 

And that's the basic method?

That's the basic methodology -- that's stereolithography. That's never changed.

Who was the first person you showed it to?

Er, my wife. I got a good part and called her up, got her out of her pajamas, told her to come down to the lab and see this.

What did she say?

"This had better be good!" (Laughs.)

And then, when did you see 3D printing take off?

Well, it's really blossomed just in the last few years -- in the sense of really rapid growth and recognition. There's a lots of things that contributed to that, I think: a lot of the medical applications catch peoples' imagination; certainly the maker movement, with low-cost machines getting hobbyists interested in inventing and building using 3D printing.

How did the process develop into what it is today?

One of the most significant [changes] is the basic accuracy you can achieve: because [the materials] cure from a liquid to a solid, they tend to shrink and they can distort. So as you build these 3D parts you get some inaccuracies and warp-age. But that chemistry has been vastly improved, so there's almost no distortion now. Also the physical properties: initially the materials were really brittle -- they would break easily. Nowadays you get really good, tough plastic materials.

I hear the word "democratization" used about 3D printing. Is that important to you?

The whole premise of this technology has been to foster creativity, and change in product design and manufacturing, and so forth. At the individual level, I think there's a great kind of pent up need: we've got into the computer age and everything is on a screen or remote, we've kind of missed the tangible result. This is a means to convert something on the computer to reality in a straightforward way.

Could you have imagined all this?

(Laughs.) Not at the consumer level. I was always thinking in terms of design engineers -- in terms of their expensive CAD computers and so forth.

What do you think the industry is worth now?

I think, well, in terms of the total goods and services, it's about US$3 billion annually and it's actually growing at a rapid rate.

Are there limits to what 3D printing can do?

There's limits to everything. So, the kind of traditional limits of 3D printing have been: material properties, speed, making millions of things. But all the competitive companies are just constantly pushing those limits, so if you're projecting the future, it looks like these limits are going to be beat down over the next couple of years.

What has surprised you most?

To me, some of the medical applications. I didn't anticipate that, and as soon as I started working with some of the medical imaging people, it became pretty clear that this was going to work. But, you know, they told me, I didn't tell them.

What does your wife say?

(Laughs) She's probably more enthusiastic than I am, so she's very excited about this whole field.

You made your discovery 30 years ago: how have you felt along these long 30 years? I mean, it's exploded hasn't it?

Well, you know I'm old enough that I should have retired long ago, but it's so interesting that I don't. It's a really interesting journey.

Aerospace Engineering: Planes are increasingly being manufacutured with 3-D printers. General Electric has been a pioneer in additive fabrication for over 20 years, but 3-D printers have largely been used in prototyping or repair capacities, until the announcement of CFM Leap engine. Engineers have designed this engine from the ground up using 3D-printing technology, which allowed them to create more complex geometries, combine 20-part assemblies into one piece while reducing weight by 30 to 40 percent.

Originally published (STORY 1) on THE GUARDIAN UK and (STORY 2) on CNN