Fabrication of Biomedical Implants using Laser Engineered Net Shaping (LENS™)

Abstract

There has been significant research, understanding of musculoskeletal disorders, but the development of suitable bone replacement materials for load-bearing applications is still lacking. Commercially available load-bearing implants/materials differ significantly from the natural host tissues in several aspects such as macro/microstructures, mechanical, physical and chemical properties. These differences limit the effectiveness of implants’ biological repair capability and longevity. One approach to enhance the cellular response and tissue integration of metal implants is to design and fabricate novel porous biomaterials that closely resemble the architecture and properties of natural bone tissue.

In this article, we review application of Laser Engineered Net Shaping (LENS™) - an additive manufacturing process developed at Sandia National Laboratories, in developing materials/structures for load bearing implant application to enhance their in vivo life time. It has been established that LENS™ process is capable of fabricating near net shaped metallic implants with tailored porosity that can eliminate stress shielding issue associated with fully dense implants. Similarly, LENS™ is a potential technique to create compositionally and/or structurally graded implants. Further, functionally graded hard coatings have been developed via LENS™ to minimize the wear induced osteolysis. Finally, mono-block or unitized structures such as functionally graded CoCrMo or TiB-TiN coating on porous Ti6Al4V can also be fabricated using LENS™. In summary, the combination of novel designs and freeform fabrication capability of LENS process might have significant effect on development of novel implants/structures using varieties of metallic/ceramic biomaterials with tailored mechanical and biological properties.

Keywords:

• Rapid prototyping
• Laser processing
• Biomaterials
• Coating
• LENS