What specific properties does the 12% or 20% carbon fibre content bring to the PEEK filament and how does this influence its adaptability to the requirements of implants?
Engel: Carbon fibre-reinforced PEEK is particularly interesting when unfilled PEEK is too elastic for an application. This is often the case with bone plates. Another example is the replacement of larger bone parts that have to bear a high load, such as entire vertebral bodies. Metals such as titanium are still often used in medical technology, but they are too rigid and can lead to high stress on the bones. They also create strong X-ray artefacts. Carbon fibre-reinforced PEEK offers an alternative with greater rigidity and more physiological mechanical properties.
The various carbon fibre components and the processing of the filament using 3D printing provide customers with unprecedented flexibility and a wide range of applications. Other processing methods with carbon fibre PEEK are often unsuitable for patient-specific solutions, but by varying the printing strategy and the fibre content, a wide range of properties can be achieved. Carbon fibre reinforced PEEK can therefore be used in many different areas and offers a better alternative to the use of metals.
How do you see the future of smart biomaterials in medical technology and what further developments can we expect from Evonik in this area?
Engel: For us, it's always about understanding the requirements and unmet needs of our customers in order to further develop our material in a targeted manner. By "smart" we always mean the combination of different properties in a product, which in turn drives performance. Examples of this include our VESTAKEEP® Fusion, a PEEK material that combines the advantages of PEEK (biocompatibility, elasticity and radiopacity) with rapid bone integration.
Many other things are conceivable, such as the combination of our PEEK materials with other biomaterials from the Evonik portfolio, such as resorbable RESOMER® or our recombinant collagen VECOLLAN®. Many customised solutions can be developed here.