Additive Manufacturing for Medical Applications – What Materials can I use?Posted on: 14th October, 2020. Filed Under: Case Studies
AM Materials for Medical Applications
Additive Manufacturing (AM) equipment and materials were first developed in the 1980s. The technology was first used for medical purposes as dental implants and custom prosthetics in the 1990s.
In recent years 3D printing for medical applications is expanding at a rapid pace and is revolutionizing healthcare as we know it.
While the benefits and the technological innovations derived from using Additive Manufacturing are outstanding, there remains some confusion when it comes to choosing the most suitable materials for your medical applications. Below we have outlined the most common materials and their usage in medical applications.
Watershed XC 11122
Applications include: Anatomical models, medical devices, field trials.
WaterShed® XC 11122 is a low viscosity liquid photopolymer that produces strong, tough, water-resistant, ABS-like properties with good temperature resistance. Specially formulated to include outstanding water resistance and high dimensional stability.
WaterShed® XC 11122 is the clear solution for designers looking for ABS and PBT-like properties for stereolithography technology. Its near-colourless appearance is like that of clear engineered plastic. This material is cleared for use for biomedical and on skin contact applications at the prototype/development stage. It is also suitable for prototyping clear medical device housings and fluid flow analysis as well as dental product applications.
Laser Prototypes Europe is ISO13485 approved to supply models to this standard.
Figure 4 MED-AMB 10
Applications include: Surgical drill guides and splints. Visualisation and fluid flow models. Medical devices that require biocompatibility, sterilisation and/or thermal resistance.
A rigid amber material for applications requiring biocompatibility, translucency and/or thermal resistance. It provides parts with fine features, that can be sterilised and tested at temperatures over 100 °C.
This material is capable of meeting ISO 10993-5 & 10 standards for biocompatibility. The crisp feature detail offers excellent visualisation for parts requiring evaluation of internal features and their performance.
SLS nylon (PA 2200)
Applications include: Prosthetic limbs, medical trials.
Laser sintered parts made from PA 2200 have excellent material properties with high strength and rigidity, good chemical resistance and finishing possibilities. It is a tough, functional material with high temperature resistance, designed for strong end user parts. Due to its excellent mechanical properties, users can substitute injection moulding for simplified, high-spec 3D printing. Its biocompatibility under EN ISO 10993-1 and USP/level VI/121°C means that it is medically approved for on skin applications.
Titanium Ti64 Eli Grade 23
Applications include: Orthopaedic implants, orthopaedic pins and screws, ligature clips, surgical staples, springs, orthodontic appliances, bone and joint replacement, dental root implants, surgical clips and cryogenic vessels.
This is one of the more commonly used titanium alloys, as it is corrosion-resistant, high strength, tough and lightweight. Usually referred to as Ti 6Al-4V, ELI (Extra Low Interstitial) grade it has lower impurity limits, especially oxygen and iron.
This material is regularly used in medical technology because of its good biocompatible, excellent fracture toughness and crack propagation behaviour. Even maintaining good fracture toughness at low temperatures. These properties as well as low elastic modules and good fatigue strength are due to the alloys low ELI.
Stainless steel (CL 20ES and CL92PH)
Applications include: Highly detailed precision mould tools, medical implants, surgical tools
Metal materials are at the first step toward high-quality results, producing very tough heat resistant components. Parts can be manufactured in high resolution facilitating the production of very fine details.
CL 20ES is an austenitic stainless steel for the production of functional parts or components for pre-production moulds. This material is used for manufacturing acid and corrosion-resistant parts. CL 92 PH is a precipitation hardening stainless steel and can be used for manufacturing functional components or medical instruments.
This detailed chart of Rapid Prototyping materials and their properties may also prove helpful to you. If you have further queries, please feel free to get in touch with us.
The Benefits of AM
A 2017 report by research company Markets and Markets indicated that the 3D printing medical devices market is projected to grow from an estimated USD 0.84 billion in 2017 to USD 1.88 billion by 2022! The report states that the Additive Manufacturing Medical Devices market is “primarily driven by factors such as technological advancements, increasing public-private funding, easy development of customized medical products, and growing applications in the healthcare industry.”
The benefits of such technology in the medical sector include:
Flexibility in the creation of complex designs that are not possible using other techniques.
Eliminates part assembly by producing the required product or component in a single piece rather than several parts.
Reduces lead-time and time to market: AM speeds up the manufacturing process, making it ideal for mass customization.
Cost-Effectiveness: AM allows for lower labour and material costs as well as lowered supply chain and production costs.
Reduction in material waste and energy: there is a significant reduction in waste materials as AM adds materials layer by layer as required, in turn reducing manufacturing and assembly to one or two steps.
“Today, it’s extremely difficult to make and assemble complex parts containing a lot of pieces or unique geometries using traditional injection molding or machining technologies,” says Forbes. “With additive manufacturing, however, there’s limitless flexibility to design complex parts, as well as combine components to streamline manufacturing and assembly of final parts while reducing supply chain costs.”
Additive Manufacturing Today
While Additive Manufacturing (AM) equipment and materials were first developed in the 1980s, the technology was first used for medical purposes as dental implants and custom prosthetics in the 1990s. Today AM plays a fundamental role not only in the MedTech sector but across all industries. In recent years 3D printing for medical applications is expanding at a rapid pace and is revolutionising healthcare as we know it. More recently, Additive manufacturing is helping save lives and prevent complete outages of key medical equipment during the Covid-19 pandemic:
COVID Case Studies
The production of a precision 1:1 scale model of a Covid-19 patient’s lungs who had been battling the virus for 14 days. This 3D model enabled doctors to better visualise how much of an impact the virus has on the lungs, giving them a better understanding of why so many people were having lasting breathing effects after they had overcome the virus.
A working ventilator was built using 3D printers and off-the-shelf components. It provided the security needed that there would be additional ventilators readily available should Irish hospitals reach capacity. Italy was one of the worst affected countries, suppliers were not able to keep up with the demand for key medical supplies. They began to run out of valves for patients on ventilators. A local innovator was able to source a 3D printer and begin manufacturing valves within 6 hours of his local hospital’s cry for help.
PPE equipment was also in short supply. An advanced manufacturing research facility based in University College Dublin (UCD) was able to design and begin manufacture of face shields for medical staff within a week.
At LPE, Belfast engineers and modelmakers have been busy helping with COVID-19 projects including ventilator manufacturing, PPE supply and hospital bed equipment. Jigs and fixtures needed quickly to cope with high levels of production required during the pandemic and even low volume 3d printed production runs to help meet impossibly tight leadtimes!
None of these innovative solutions would have been achieved so efficiently or effectively using traditional manufacturing methods. The ability to design and develop prototypes quickly, allowed time for validation and approval from relevant bodies before full-scale manufacturing began.
No doubt helping to save lives during a global pandemic!
Recommended reading: A report by Deloitte titled: “3D opportunity in medical technology: Additive manufacturing comes to life” provides some great insights into AM for the MedTech market.
“Stereolithography models allow us to do production intents within days. On one project alone it saved us £100,000 in tooling costs and reduced the lead time from 7 months to 7 days”