(Source: elenabsl – stock.adobe)
3D printing (aka additive manufacturing) is now being used for many applications across a wide range of industrial and consumer sectors. 3D printing has gone from being a small novel technique that can print plastic trinkets to one of the most versatile manufacturing methods today. While the lower-tech applications are still used by people on small printers, the development of large-scale plastic printing and metal 3D printing on a commercial level means that 3D printed parts are now in a range of high-tech sectors, including airplane jet engines.
But what about the medical sector? The medical industry is highly regulated. Parts, components, and devices need to meet medical standards. In addition, many processes, materials, and products must be certified before they are used in a clinical setting. Even though 3D printing of medical parts is a relatively recent development, many medical devices created through 3D printing been successfully used in clinical settings for personalized medical procedures where a specific part or device must be customized to fit the patient.
Several 3D printing methods are available, and they vary depending on the type of medical device being printed and the materials used. Some 3D printing methods are specifically used for printing polymer parts, whereas others are strictly for metal parts, while some methods are capable of printing both materials. All methods have their distinct advantages and challenges depending on what needs to be printed.
Sometimes, the cost of the material and processes drives a choice. Other times, it is driven by the ability to create a specific geometry or printed features with a particular material. Still, other times it is driven by the final performance of the printed part itself and which method will give the best properties and surface finish. Each method has advantages that enable medical professionals to achieve one or more of these factors.
Depending on the required device, the machine used, and the raw materials, the challenges could include the cost, roughly finished surfaces, poor mechanical properties—such as porosity and bad microstructure if the wrong technique is used—or a low throughput. However, because there are several specialized techniques, many of these factors can be avoided by choosing the method that offers the best advantages and finish for the least trade-off.
So, which methods are used? While there are some lesser-used methods—like stereolithography and fused filament fabrication (FFF)— three common methods—and the methods expected to have the greatest commercial developments and real-world use cases are:
LPBF is a laser-based process that is commonly used with polymers, but it is starting to gain use with metals and metal alloys, as well as being usable with ceramic materials.
Binder jet is a heated nozzle process that works well with polymers. This process has been expanding out to metals and ceramics recently, and while it has the highest throughput of all the methods, the properties and quality of the finished part is sometimes not as high as other methods. So, the use of binder jet typically comes down to cost vs. performance for the intended medical device and whether the extra finish and or properties are going to be of benefit to the device for the cost.
EBM uses an electron beam to melt and fuse the powder into a part. It is typically used with metals because it offers the best finish and material properties of all the techniques. As a result, EBM is often the go-to technique for metals and metal alloys, especially higher temperature alloys, even though the other methods are suitable for metals. Metal alloy medical devices are typically created for long-term use and to be resistant to wear, so often building for performance is the driving factor of these medical devices over cost.
3D printing is making waves in many industrial and consumer sectors, and it is starting to gain traction in the medical device space. Several 3D printing methods can now be used to create polymer, ceramic, and metal medical devices customized to a patient’s specific needs. Some 3D printing methods considered well-suited for medical devices include LPBF, binder jet, and EBM. Because each method has advantages and challenges, medical professionals often weigh several factors when employing 3D printing to customize a medical device for a patient such as:
Liam Critchley is a writer, journalist and communicator who specializes in chemistry and nanotechnology and how fundamental principles at the molecular level can be applied to many different application areas. Liam is perhaps best known for his informative approach and explaining complex scientific topics to both scientists and non-scientists. Liam has over 350 articles published across various scientific areas and industries that crossover with both chemistry and nanotechnology.
Liam is Senior Science Communications Officer at the Nanotechnology Industries Association (NIA) in Europe and has spent the past few years writing for companies, associations and media websites around the globe. Before becoming a writer, Liam completed master’s degrees in chemistry with nanotechnology and chemical engineering.
Aside from writing, Liam is also an advisory board member for the National Graphene Association (NGA) in the U.S., the global organization Nanotechnology World Network (NWN), and a Board of Trustees member for GlamSci–A UK-based science Charity. Liam is also a member of the British Society for Nanomedicine (BSNM) and the International Association of Advanced Materials (IAAM), as well as a peer-reviewer for multiple academic journals.