Manufacturing | Article

Comparing Additive Manufacturing in Aerospace and Medical Devices

As 3-D printing’s disruption continues, these two fields are leading the charge.

Written by: Adam Kimmel

Manufacturing in the aerospace and medical device industries appear to have little in common. The size and cost of aircraft and spacecraft differs drastically from nanoscale biology and disposable medical device components. Regardless, these two industries share one crucial facet: They are both at the forefront of additive manufacturing (AM).

The aerospace and medical device industries have been crucial in driving AM into the mainstream. Once thought to be only a tool for packaging and aesthetic prototypes, AM, through the use of advanced 3D printing, has become a legitimate manufacturing process. With a global market size of $8.44 billion in 2018, AM is expected to grow to $36.61 billion by 2027.

Aerospace

The aerospace industry has been an early adopter of transformative technology before. It was the first to adopt carbon fiber material and to employ computer-aided design (CAD) as a product design tool. With the implementation of AM, the industry is now undergoing significant disruption in manufacturing, with many improvements tied to weight reduction. Current aerospace applications for AM include lighter plane seats, helicopter components, fuel injection nozzles, fuselage panels, military drones, and turbines.

An example of the weight savings is a plane seat made by Autodesk, which boasts a 54% weight reduction over existing seats through 3D printing a seat mold. This technique was used to weight-optimize the final ceramic seat mold for production launch, offering significant fuel savings during flights.

Engineers at aerospace manufacturer Pratt & Whitney realized another weight reduction improvement. They 3D printed fuel injection nozzles, collectors and fasteners from nickel and titanium to reduce the total engine weight by 50%.

Aerospace engineers generally use AM techniques to improve performance in terms of reduced weight, fuel consumption or power. Limited by the size of commercially available printers, the technology currently enables product developers to rapidly produce and test new concepts, such as complex geometries that traditional manufacturing cannot produce and scale models of new aircraft cabin or automonous drone technology, albeit at a smaller scale than many full-size aircrafts.

The most likely niche for AM in this industry is as an augmentation to existing manufacturing methods, many of which are used to produce high-volume parts. AM is not yet advantaged at mass production when compared with tooled, mature processes.

Each industry began implementing AM for small-scale, complex parts with many integrated/included features. This approach progressed to customized production.

Medical devices

Medical device manufacturers already use AM to fabricate devices such as artificial hip joints, as well as spinal and dental implants. Like aerospace, this industry brought the technology into mainstream development by implementing it at the rapid prototype level. 3D printing primarily benefits the creation of orthopedic devices because of the complexity that the process can incorporate into a single component, such as single-step production of rotating joints in shoulders, knees and hips.

“The medical field is already well aware additive manufacturing is used to manufacture implants, with about 79% of those being titanium implants, according to a recent FDA analysis,” said Laura Gilmour, global medical business development manager for EOS. “Pioneers in the field are getting clearance of third or fourth implants such as reverse shoulder, spinal cages, or hip revision devices. In fact, titanium acetabular cups and patient-specific cutting guides recently achieved 10-year clinical histories.”

While the increase in additive manufacturing with metals has affected the supply chain, 3D printing has mainly affected the fabrication of plastic parts. While traditional metal manufacturing processes remain more cost competitive than AM at high volumes, AM is affecting the practicality of injection molding up to quantities in the tens of thousands.

For the healthcare industry, the ability to artificially create transplant organs offers nothing short of a miracle to patients who otherwise may never receive a compatible body part. AM also can fabricate layers of tissues. A 2017 Gartner study projected that the industry is five to ten years away from printing patient-specific transplant organs.

Gilmour also offered perspective on coming trends in AM for the medical device field: “Point-of-care manufacturing seems to be the next big question for the orthopedic field, with the FDA sharing some initial risk-based approaches at the RAPID conference [in 2019]. Additive manufacturing opens new considerations for a supply chain, which hospitals and providers seem to want to take advantage of in the near term,” she said.

In addition to some barriers to wide-scale adoption—which aerospace also experiences—the regulatory landscape lags in clarifying guardrails for medical device manufacturers. Class I devices are permitted to use AM without additional pre-screening, as long as it is similar in design and function to existing products. Class II products, conversely, must meet ISO or ASTM standards explicitly developed for AM due to the risk of the applications. These standards may not agree with each other, leading to manufacturer confusion.

Lessons from overlap

The use of AM to improve and optimize the efficiency of manufacturing has made it a legitimate tool for production fabrication in the aerospace and medical device industries. Each industry began implementing AM for small-scale, complex parts with many integrated/included features. This approach progressed to customized production, and both industries now are poised to continue the use of 3D printing for transformative innovation.

While the technology is no longer brand-new, the range of applications, the integration with existing processes, and the extension of equipment capability that AM offers are poised to continue to disrupt mass manufacturing.