UK additive manufacturing research leads the field
The UK is setting the pace in the race to develop next generation, multi-material and multifunctional additive manufacturing technologies, and this looks set to continue with a number of dedicated centres appearing at universities all over the country.
The most recent of these is at the University of Southampton, which has just opened a state-of-the-art rapid prototyping facility aimed at 'transforming engineering design', while 2011 saw the development of an EPSRC Centre for Innovative Manufacturing in Additive Manufacturing, which is led from the University of Nottingham with Loughborough University as a partner.
Another facility to open last year was the £2.6million Centre for Additive Layer Manufacturing (CALM) at the University of Exeter, reflecting a new emphasis for the University. "The University of Exeter has been involved in additive layer manufacturing for a number of years, but it's only in the last two that the technology has really been classified as a core focus for us," says James Bradbury, a research and application engineer at CALM. "Our main goal at the centre is to work with SMEs from different sectors to help them discover what they can and can't do with the technology and show them how they can apply it to better their product. We also want to work with industry partners across different sectors, primarily aerospace, automotive, defence and medical, to really explore what the technology is capable of."
CALM has already engaged with more than 300 businesses worldwide in the 18 months it has been operational, offering services such as 3D printing, laser sintering, laser melting and deposition/extrusion processes. Bradbury and fellow engineer Richard Davies also run workshops where companies can get a general introduction to the technology and see what other people have used it for.
In July last year, the CALM researchers grabbed headlines by developing the first ever 3D chocolate printer, while a more recent project saw them help Bristol-based start-up nu desine create a brand new musical instrument called AlphaSphere, which reinterprets the way users interact with sound. The instrument is made up of 48 pressure-sensitive pads which form a self-supporting spherical structure. Sound is triggered when a user taps the pad or applies more pressure so that they can mould and manipulate the sound further. Users can also supply parameters to the pad depth such as pitch-bend, volume, oscillations and interesting filters.
"We decided to create AlphaSphere using selective laser sintering (SLS) for a number of reasons," noted nu desine vice president and product design engineer, Richard De Lancey. "First, the layer-by-layer approach to building a model in a powder bed allowed for complete geometric freedom of design. With a complex structure such as the AlphaSphere, this allowed me to prove the concept without concerns for the geometric restrictions of other model building processes. Secondly was the speed of the process: we were able to get the finished parts in just over a week, which sped up the process of design iterations rather than waiting for the longer lead times of other processes. Thirdly, SLS is a fully-automated method, leaving no room for human error. The final factor was the cost. Although much more expensive per part than alternative methods, with SLS there are zero tooling costs. This worked out considerably cheaper during the R&D phase as we didn't have to commit any money to instantly redundant tools."
The CALM researchers also used SLS in a project to develop a new manufacturing process for cheaper, easier-to-produce aluminium composite parts for the aerospace and automotive industries. Bradbury believes the process has the potential to manufacture exceptionally strong yet lightweight structural components such as pistons, drive shafts, suspension components and brake discs. The method involves using a laser to melt a mixture of powders composed of aluminium and a reactive reinforcing material. A reaction between the powders results in the formation of new particles, which act as reinforcements and distribute evenly throughout the composite material.
According to Bradbury, the new materials have very fine particles compared with other composites, making them more robust. The reaction between constituents releases energy, which also means materials can be produced at a higher rate using less power. "This technique is significantly cheaper and more sustainable than other methods, which directly blend very fine powders to manufacture composites," he explained. "We believe the development has great potential to make high performance parts for car manufacturing, the aerospace industry and potentially other industries."
Bradbury envisions a time when everything from the complex aircraft parts mentioned above to customised jewellery and mobile phones can be created using additive manufacturing. "The industry has seen a big boom recently in low-cost 3D printers and that's because a lot of the original patents for the technology have run out," he says. "Most of the systems we currently use are still heavily patented, but that's all about to change. Once these expire, we expect the technology to hit the mainstream within the next 10 to 15 years. It's likely that the automotive world will catch on first, with the medical and aerospace industries following close behind."
Bradbury predicts that materials will be the biggest growth area in the industry. He also sees the industry moving towards more hybrid methods, whereby multi-material products can be developed as a single product. This view is shared by Dr Martin Baumers of the EPSRC Centre for Innovative Manufacturing in Additive Manufacturing and Professor Lee Cronin of the University of Glasgow, who both describe the technology as nothing less than "revolutionary".
Dr Baumers and his colleagues are currently working to create multi-material, multi-functional devices with amalgamated electrical, optical and structural properties, such as next-generation mobile phones – in a single manufacturing process. Professor Cronin, on the other hand, is currently working on a new 3D printing process that he claims could revolutionise the way drugs and other chemicals are made in the future, and even enable consumers to create customised medicines at home.
"3D printers are becoming increasingly common and affordable," he noted. "It's entirely possible that, in the future, we could see chemical engineering technology which is prohibitively expensive today filter down to laboratories and small commercial enterprises. Even more importantly, we could use 3D printers to revolutionise access to healthcare in the developing world, allowing diagnosis and treatment to happen in a much more efficient and economical way than is possible now.
"We could even see 3D printers reach into homes and become fabricators of domestic items, including medications. Perhaps with the introduction of carefully-controlled software apps, similar to the ones available from Apple, we could see patients have access to a personal drug designer they could use at home to create the medication they require."