Pellet extrusion additive manufacturing of carbon nanotube reinforced peekbased composites for biomedical applications

Spinal implants are prosthetic structures used to alleviate the negative effects of vertebral fractures, back pain, scoliosis, and degenerative disc disorders. Metallic alloys are frequently utilized in the production of implants within the healthcare industry. However, challenges encountered in the manufacturing process, the occurrence of certain allergic reactions within the human body, and medical imaging artifacts prompted researchers to develop medical implants using polymers. This study focuses on the development of carbon nanotube (CNT)-reinforced composites based on polyether ether ketone (PEEK) for the production of spinal implants. In this study, PEEK and CNTs were blended utilizing twin-screw extrusion to fabricate the composite pellets employed in pellet extrusion additive manufacturing. As the spine is primarily subjected to compressive loadings, compression test specimens were printed and tests were conducted. Following experimental characterizations, structural analysis of a pellet extruded spinal implant through the finite element method (FEM) was performed considering the loading cases mimicking daily human body motions.