Design for AM

Additive manufacturing comes into its own

T welve years ago, two European companies began discussing how to improve the fit and comfort of hearing-aid earpieces. Belgian 3D-printing company Materialise developed the software and provided expertise, and within three years Swiss hearing aid-maker Phonak was printing hundreds of finely customised earpieces at a time, at its Zurich headquarters. In another three years it was producing locally on small 3D printers all over the world.

“Millions of people are using hearing aids made by additive manufacturing [AM]. Without being aware of it, they have already changed industries,” says Jo Anseeuw, managing director of Yokohama-based Materialise Japan.

The 3D-printing industry is evolving rapidly. The technologies gained popularity during the 1990s, used for rapid prototyping throughout the automotive and other industries. More recently, improved techniques, better materials and more powerful software have brought a growing list of successes in low-volume customised manufacturing.

“It is becoming distributive manufacturing,” says Anseeuw. “There is central data management, but manufacturing and distribution are spread worldwide on a regional basis.”

Materialise was set up in 1990 by its current CEO, Wilfried Vancraen, as a joint venture with the University of Leuven in Belgium. It wasted no time in commercialising an impressive list of systems. By 1999 it had already expanded to the United States, France, Germany and the UK. With a staff of 800 and growing, it now boasts Europe’s greatest AM manufacturing capacity. In June, industry professionals worldwide voted the soft-spoken Vancraen the most influential figure in AM today. Materialise Japan was set up in 2000.

“Our main functions here are software sales, engineering services and consulting. We are also working on some special projects with customers,” says Anseeuw. He declines to spill the beans on which companies, or even industries, may be about to join what some call a new industrial revolution.

The stakes are high. Early adaption vaulted Phonak from 5th place to the top of its field. Now the various sports-shoe makers, for example, are nervously watching each other for signs of a game-changing switch to AM. In many industries, a successful application could totally redraw the competitive environment by lowering costs, making customisation the norm and migrating production back towards the point of sale.

AM is a way of producing a three-dimensional object from a digital file. The 3D computer image is divided into virtual cross-sections, whose data are used to materialise successive layers of the solid object.

There are a number of variations. In photopolymer stereolithography, an ultraviolet laser is used to cure successive layers of resin in a vat. Greater precision can be achieved with a method called selective laser sintering, by which a high-powered laser fuses particles of plastic, metal, ceramic or glass into the desired shape. Direct metal laser sintering, using a bed of almost any kind of alloy powder, is ideal for short production runs of functional components or tools.

Another technique, called fused deposition modeling, uses computer-aided manufacturing software to guide an extrusion nozzle, which deposits beads of material (as small as 0.04mm thick) that harden immediately. Yet another method uses an electron beam to melt titanium alloys in a vacuum.

The basic idea, printing cross-sections of a 3D digital model, is the same in all cases. The model itself, though, can be created using design software, or derived from electronic or electromagnetic scanning.

It is now a simple matter to scan a small, complex shape such as a dental implant or bridge. Dental fabrication is another industry that has already switched to AM, with machines turning out hundreds of individualised pieces at a time for hundreds of patients across a given region.

“The challenge is that you have to tell one item from another,” says Anseeuw. “We develop software to track customised medical parts.” It is not just a matter of matching the part to the patient.

“After the operation, you must be able to track the part back to a certain machine on a certain day, with a record of who was operating the machine, the materials used, the settings and so on,” explains Sadato Kobayashi, Materialise Japan group manager. “If a patient has a problem with a part, you may have to notify other patients of a potential problem.”

In hospitals, AM is also transforming surgery. In partnerships with major orthopaedics companies, Materialise has developed surgical guides that shorten operation times for thousands of patients every month. 

“We print a patient-specific guide that fits on the bone, with slots. The doctor can drill accurately and quickly,” explains Anseeuw. The aim is to reduce the strain on surgeons as well as patients by minimizing the guesswork involved in complex procedures and this often also reduces surgery time. There are great advantages in being able to plan a surgical process in three dimensions rather than two. Surgeons are now performing operations not previously regarded as possible.

Bordering on the impossible was a procedure carried out last January at Belgium’s Ghent University Hospital.
The patient required replacement of most of the lower facial bone and the attached soft tissue. Based on scans of both patient and potential donor, Materialise developed a detailed virtual pre-operative plan and built AM operating guides, reference models and prosthetics. With the parts in place and fitting perfectly, surgeons then connected recipient and donor blood vessels, motor nerves and sensory nerves.

Having seen a video of what the 65-strong medical team accomplished, Anseeuw and Kobayashi agree: “The most amazing thing was to see the face turn red the moment they connected the blood vessels.”

Understandably, Materialise generates a lot of attention for its work in the medical field, but Anseeuw and Kobayashi stress that there is much more to the picture.

“There are plenty of companies with machines, and a few that develop their own software,” says Anseeuw, “but there is no other company with many machines, developing its own software, and also involved in the medical field.”

“Our main advantage is the overlap of those three core competencies. That’s where we are unique,” says Kobayashi.

The Japanese AM landscape includes a company called Aspect, with some software and several brands of machine, CMET (formed by a group of large manufacturers and NTT Data) and Matsuura Machinery, which has a machine that combines laser sintering and high-speed machining.

There is plenty of room for the international players (a few with Japanese offices, but most via Japanese distributors). Some of them partner with Materialise and use Materialise software.

NTT Data is the main distributor for German company EOS, while Marubeni fills that role for US company Stratasys. 3DSystems (US) has a Japan subsidiary. Others active here include Israeli company Objet, EnvisionTec of Germany and Swedish company Arcam, which specialises in electron-beam melting of alloy.

“Huge potential for further expansion” was one of the reasons for Materialise being awarded the Nippon Export Award 2011–2012 by the Belgian–Luxembourg Chamber of Commerce in Japan last December.

In fact, Materialise is expanding in many directions. Through i.materialise, launched in 2009, anyone in the world can print in 3D. A customer who uploads a design is shown a price for printing and a choice of 20 materials, and then can scale the model to the optimal size before printing as many copies as he or she wants. They can even put their work up for sale in the i.materialise online store.

Items of jewellery – in gold, silver, stainless steel and other materials – are popular on i.materialise. The jewellery industry is picking up fast on the potential of 3D printing, and Cookson Precious Metals of the UK and EOS recently signed a strategic development partnership for the purpose of developing applications for the jewellery and watch industry.

AM is influencing medicine, DIY, fashion and art, but industrial applications are the most exciting for Anseeuw and Kobayashi. Materialise helped to develop a lighter, stronger and more comfortable steering wheel for a car to be entered in Australia’s World Solar Challenge. The key to lightness and strength was a fine reinforcement web inside the hollow circular tube, a structure that could not be achieved economically with traditional tooling.

“Conventionally, engineers are bound to what can be done with certain tools. But AM is not tooling, so you can design more freely,” explains Kobayashi. “This can mean a lot in terms of aesthetics, structural integrity and weight. You can optimise geometries.”

The aerospace industry is becoming seriously interested in the advantages – such as complex assemblies being fabricated as a single piece with less weight – that AM can deliver. After all, reducing the weight of a passenger jet by 1kg will save several tons of fuel over the life of the aircraft. One of the challenges is education.

“The mindset of a lot of engineers will have to change,” says Anseeuw. “For example, engineers using injection moulding think about the limitations of materials used in injection moulding. They are not thinking of the limitations for AM, so they don’t readily grasp the potential. They are not designing for AM.”

Universities, he says, will have to start teaching design for AM, showing engineers how to go beyond the old assumptions.

And he adds: “Industrial production is where the real revolution will take place.”

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David is Editor-in-chief of EURObiZ Japan