Poly-Ether-Ether-Ketone (PEEK) Biomaterials and Composites: Challenges, Progress, and Opportunities

Polyetheretherketone (PEEK) is a lightweight, bioinert, high-performance thermoplastic that is beginning to see clinical use in orthopedic applications. PEEK outperforms conventional metallic counterparts in terms of reduced stress shielding and improved chemical resistance, making it highly suitable for implantable applications. However, despite its excellent mechanical properties, the elevated melting point (343 °C) presents significant challenges during manufacturing. Furthermore, PEEK requires surface modifications to enhance antibacterial, bioactive, and osseointegration properties suitable for invivo applications. In this context, the present manuscript highlights current manufacturing challenges for implantable PEEK biomaterials and typical fiber reinforced PEEK composites. Emphasis is placed on reinforcements such as carbon fiber (CF), hydroxyapatite (HA) and titanium dioxide (TiO2), along with multi-material PEEK composites and their applications. Opportunities are identified to address these challenges, contributing toward the development of synergetic, multi-functional PEEK biomaterials suitable for long-term implantable applications.