Innovative Biomechanical Design and Performance of Carbon Fiber-Thermoplastic Implants via Additive Manufacturing

Area of Science:

• Biomaterials Engineering
• Additive Manufacturing
• Orthopedic Implants

Background:

• Conventional metallic implants like Ti-6AL-4V titanium alloy face limitations in promoting bone healing.
• There is a need for advanced implantable materials with improved bio-mechanical properties.
• 3D printing offers potential for creating complex implant geometries and customized solutions.

Purpose of the Study:

• To evaluate 3D-printed carbon fiber-reinforced thermoplastic composites (Nylon, PEEK) as alternatives to titanium alloy for medical implants.
• To compare the mechanical performance and bone healing potential of novel composite designs against traditional titanium implants.
• To provide design guidelines for fused filament fabrication (FFF) 3D-printed composite implants.

Main Methods:

• Fused Filament Fabrication (FFF) was used to 3D print carbon fiber-reinforced Nylon and PEEK composites.
• Experimental analysis and Finite Element Method (FEM) simulations were employed for evaluation.
• Performance was assessed based on screw pull-out force, bio-elastic coupling strain energy density (SED), screw loosening, bone remodeling, and resorption.

Main Results:

• Novel discontinuous carbon fiber-PEEK and continuous carbon fiber-Nylon composites reduced screw pull-out force by nearly 50% compared to Ti-6AL-4V.
• Thermoplastic composites exhibited significantly higher bio-elastic coupling strain energy density (SED), suggesting enhanced bone healing potential.
• Multi-criteria evaluation showed 3D-printed composites outperformed titanium by 33%-65% in key performance metrics.

Conclusions:

• 3D-printed carbon fiber-reinforced thermoplastic composites demonstrate superior performance over titanium alloy for medical implants.
• These materials show significant potential for promoting bone healing and callus formation.
• The study provides valuable design guidelines for developing effective, customizable 3D-printed composite implants as alternatives to metal implants.