3D printing building up hopes of revolutionising engineering

Sheffield University is redeveloping The Mercury Centre, which is based within the Department of Materials Science and Engineering, to expand its expertise in 3D printing.

It has received £5m from the European Regional Development Fund to buy five new machines and pay the building’s running costs until 2013. Building work is due to be completed in July this year.

The university has been using 3D printing technology for the last four years. So far it has produced artificial knee and hip replacements, lightweight hinges for the aerospace industry, and brackets for Formula One cars, but in the future it will be able to make much larger parts.

Three-dimensional printing has been used for more than a decade, but mostly to produce bracket prototypes quickly and cheaply before they produce the real thing out of solid metal. However, as 3D printers develop their capabilities, they are being used increasingly to make final products.

The 3D printers work like ordinary desktop printers but instead of putting down ink on paper, they stack up layers of material to make 3D shapes.

The machine that Sheffield University currently has produces objects out of metals, such as titanium, but other machines can create objects out of plastic, nylon and ceramics.

Each layer takes about 30-40 seconds to produce, so depending on how large the part is, it can take between two and 40 hours to make an object.

Dr Iain Todd, director of the Mercury Centre, said: “We are trying to make this a viable manufacturing process.

“We are working with industrial partners such as Rolls Royce, Boeing and Airbus, to find a way of ensuring that when we make things this way, they are going to behave just like they would if they were made out of a solid piece of metal and have it machined or with casting.”

He added: “These companies are already using this technology. It’s used for all sorts of things and it turns up in all sorts of surprising places.”

According to Dr Todd, the technology is no more expensive in terms of outlay than a standard milling machine. Staff and running costs are also similar.

“It competes in an economic sense with forging and casting, although we can only make very small parts,” he said.

The size of the objects produced by the metal printers is the main disadvantage, although once the centre is redeveloped, it will be able to produce parts four or five times bigger than its current capacity.

The existing printer has a maximum capacity of 200mm x 200mm x 350mm. “That’s the biggest bit I can make, and even then I’d want to make it slightly smaller,” said Dr Todd. “However, the advantage is, within these constraints, if you can draw it then you can probably make it.

“It allows you to have a very flexible piece of equipment in the corner of the room that one day could be making acetabular cups, which is a medical part. The next day you could be making Formula One widgets. I know we can do that with milling machines but the turnaround time with 3D printing is very short.”

Another advantage is the amount of waste material produced. In the last four years, Sheffield University has produced enough waste to fill just one office bin.

According to Dr Todd, 3D printing is already transforming manufacturing. “The larger multi-national companies are putting a lot of effort into this and they wouldn’t be doing that if they didn’t think it had an advantage,” he said.

“The main advantage it seems to offer is that it creates a more sustainable manufacturing route for certain products. It also allows you to make complicated parts. But clearly, if the big multi-nationals are going after it, they are also looking at mass production.”

Although established mass-production techniques are unlikely to be replaced completely, factories are already using 3D printers alongside milling machines, presses, foundries and plastic injection-moulding equipment.

Consumers can also get involved in the process. Hewlett Packard has already started to produce small 3D printers for £12,000, a fraction of the price of its bigger brother, which can cost hundreds of thousands of pounds to buy.

Schools are also getting interested, buying versions of 3D printers for as little as £750. “Pupils are getting used to the technology, and that’s the most exciting thing about it,” said Dr Todd.

But for now, the development of the technology is being led by the major multi-nationals. Dr Todd said: “I think there’s going to be massive changes in the way the major companies manufacture soon and that will filter straight down into the supply chain.”

FRESH HOPE FOR MANKIND

PRINTING metals and plastics is one thing, but tissue engineers are taking three-dimensional printing to the next level in the hope of using the technology to create human organs.

Experts all over the world are working towards one daring goal: to print a functioning human liver, kidney or heart using a patient’s own cells.

Bioprinting technology is years and possibly decades from producing such complex organs, but scientists have already printed skin and vertebral disks (the soft tissue that grows in the spine between the vertebrae) and put them into living bodies. It is thought that a few types of printed replacement parts could be ready for human trials in two to five years.