ERI: Development and Characterization of New Antimicrobial PEEK (Polyetheretherketone) Filaments for Material Extrusion-based Additive Manufacturing Technology

Additive manufacturing, or 3D printing, has great potential for making customized patient-specific implants and biodevices in complex shapes. Currently available raw materials used for printing polymer devices for these purposes are mostly not strong enough or do not possess antimicrobial characteristics, which make the implants and biodevices susceptible to microbial infection. Such biodevice-related infections burden the healthcare system and threaten patients’ lives. This Engineering Research Initiation (ERI) award supports fundamental research to provide the knowledge needed to make strong antimicrobial materials for 3D printing. A composite in filament form will be made from polymers in the PAEK (polyaryletherketone) family, which is known to be strong, and silver nanoparticles, which are known to have a broad spectrum of antimicrobial activities against bacteria, fungi, and viruses and low toxicity to living cells. The new materials will allow the fabrication of customized implants and biodevices that are strong and inherently antimicrobial. This research will contribute to knowledge in the areas of advanced manufacturing, biomedical engineering, materials science, and microbiology. The multi-disciplinary research will be incorporated in course content. The extrusion of antimicrobial filament of the PAEK family with incorporated silver nanoparticles presents two challenges: agglomeration of the nanoparticles within the polymeric matrix, which significantly reduces the antimicrobial efficacy, and variation of the filament diameter, which produces defective parts when extruded during additive manufacturing. This research investigates the hypothesis that adding a dispersion agent will prevent the agglomeration of the silver nanoparticles and improve the extrusion process. The research team will conduct experiments to determine the relations between silver nanoparticle and dispersion agent contents and antimicrobial efficacy, dispersion uniformity within the polymeric matrix, cytotoxicity, and fabricated part mechanical properties. An algorithm will be developed to optimize the extrusion process parameters for polymeric nanocomposites and will be validated using the experimental results. Characterization of 3D printed test specimens, including antimicrobial efficacy, cytotoxicity, thermal, morphological, and mechanical properties, will be performed to establish the relationship between process parameters and properties of the new antimicrobial PAEK nanocomposites. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.