Three-dimensional printing

Management of bone diseases such as arthritis, trauma and fractures frequently requires the implantation of prostheses, internal fixation devices including fixation plates, rods and screws. Issues raised from the medical implants which limit the long term success of orthopaedic surgery are inaccurate sizes of implants, non-personalized design of implants, weak adhesion strength of coating material on the surface of implant, and wear debris accumulation caused by imprecisely fitted de-vice around the bone surface.

The 3D printing technology provides a promising way to solve these problems through personalized and procession medical devices. The advancement of additive manufacturing (AM) technique with laser power has been offering an ideal way for personalized and precision manufacturing, which caters the requirement of bone implant fabrication owing to its tailored made solution. Furthermore, powder based techniques of AM technology have the unique ability to build metal items with precise surface and inner structure. Therefore, we hypothesize that a 3D printable personalized medical implant model for precise orthopaedic device can be reverse modelled and improved via miro-CT reconstruction from clinical images, and multiple manufacturing processes will be applied on one implant using different manufacturing methods, which possess superior biocompatibility and biofunctions by different materials.

This research targets on better applying the powder based AM technology in orthopaedic industry based on following four main objectives:

  1. Advance laser based AM technique with multiple manufacturing process compatibly achieve a single implant establishment process. Material limitation on a single 3D printer is one of the most significant barriers to 3D laser printing development. The proposed system will be designed and prototyped to be capable of applying different manufacturing pro-cesses into one to better utilize correspondent advantages. More than one material can be used to produce parts with specific requirements which cannot be met by a single material, such as graded composition, coating systems, and locally controlled properties.
  2. Produce medical implement coating with high degree of adhesion. Current medical implement coating is a separated process to the fabrication of the implant substrate, by which the risk of coated layer detaching from the implant always exists. This research integrates the coating process to the implement fabrication process via the proposed AM technique, which enables the coating entangles to the substrate to form strong mechanical bond between two dissimilar materials.
  3. New surface polishing technique for the improvement of wear resistant. Combining AM process with polishing process leads not only simpler and faster procedure but also the component with denser interior and smoother surface.
  4. Standardizing the performance and biocompatibility testing of the AM implants for the guide of the development of medical implant industry.