Print works

3D printing – the additive fabrication of objects by depositing and patterning successive layers of material – has been touted as an enabling platform for applications ranging from lighter, more efficient aircraft and advanced prosthetics to homemade firearms and lab-grown organs. Among all the hype, the true impact of 3D printing is uncertain. Currently, 3D printing’s largest applications are for making prototypes, moulds, and tooling. Direct production of end use parts, however, is beginning to grow in industries including aerospace, medical, automotive, consumer products, architecture, and electronics as a way to reduce costs and improve performance. Producing a traditional machined mould or other tooling for a part design can require tens of thousands of dollars and weeks to months of time, but 3D printing enables production of the same part, often overnight, for only the cost of materials. This, in turn, enables affordable low-volume manufacturing applications (one unit to a few thousands of units) or custom or short-run parts and devices. The ability to rapidly iterate designs and to make unique, customized objects with complex shapes can further enable superior end part performance.

Medical device companies, surgeons, researchers, and even private individuals have begun using 3D printing for a range of medical applications. The most commonly discussed of these are in dentistry, where printers are used to produce crowns, bridges, stone models, and orthodontic appliances. However, applications including surgical tools and guides, orthopedic implants, and prosthetics are already in use in laboratories and small-scale commercial production. For example, some surgeons are using Mcor Technologies’s printers, which build objects out of sheets of paper with adhesive, to produce patient-specific, potentially full color surgical guides to practice difficult procedures or to use as a reference in the operating room.

Printed orthopedic implants in particular are beginning to gain traction, in part due to the ease with which they can be customised to the needs of each individual patient. In 2011, Arcam (a metal 3D printer manufacturer in Sweden) announced that one of its customers received FDA approval for titanium orthopedic implants (initially knee and hip replacements) made using its equipment. In 2013, Oxford Performance Materials, a 3D printed part developer in Connecticut, announced its own FDA approval for cranial implants made from PEKK (a high performance thermoplastic) using EOS’ laser sintering 3D printers, and sold through its partner and distributor, Biomet. While it is not yet clear whether the customisation from 3D printing leads to improved clinical outcomes, as a manufacturing technology it enables faster design processes and increased materials utilization (compared to subtractive machining processes), allowing Oxford Performance Materials to reduce its production costs by more than 80%.

In 2013 and 2014, several enterprising individuals even designed and printed their own prosthetic limbs. Those individuals cite improved aesthetics and orders of magnitude lower costs as motivation. Cost reduction and the potential for just-in-time design and production also motivate aid group iLab Haiti to use low-cost desktop 3D printers at clinics in Port-au-Prince, where it is difficult to maintain stocks of many standard parts. Instead, the printers make basic supplies such as umbilical cord clamps on-site, as needed, from a single feedstock material.

These current applications are just the beginning. University researchers have begun developing materials and showing proof-of-concept demonstrations of 3D printed objects with integrated electronics functionally such as wiring, antennas, touch sensors, and even electrochemical cells. Down the road, these materials could enable one-step production of compact, integrated devices. Bioprinting – the deposition of living cells – goes still further. For example, startup Organovo has demonstrated the ability to deposit and grow layers of functional human cells including liver, lung, kidney, and heart tissue. In the near term, Organovo claims its tissues can reduce the cost of drug development by enabling measurements of efficacy and toxicity to screen drug candidates using a safe human model at lower cost than animal trials. In the long term, the company targets production of complete organs for transplant.

However, significant challenges remain before these possibilities can be realized. One universal challenge is that printable materials, especially plastics, were developed to meet the needs of prototyping applications, where a convenient solution that worked “out of the box” was more important than functionality. As a result, selection is limited to perhaps a few dozen polymers, and mechanical performance lags behind conventionally molded plastics. Numerous start-ups, academic groups, and government laboratories are working independently to improve performance and to develop a wider selection of printable materials, but years of additional research and development are needed to reach commercial maturity.

About the author

Anthony Vicari is a research associate on the advanced materials team at Lux Research, where he covers technological and market developments in emerging materials and manufacturing technologies. Prior to joining Lux Research, Anthony was a research and development scientist at InnovX Systems.