Performance Evaluation of High-Density Polyethylene Micro/Nano Hydroxyapatite Composites for Biomedical Implants: An Experimental and Numerical Study.

Due to the increasing need for reconstructive surgeries, the use of medical implants has become more common. These implants are used to treat a variety of orthopedic diseases, defects, traumas, and congenital anomalies such as bone cancer, bone fracture, and osteoporosis. As a result, it is essential to develop biomaterials with specific properties to improve, substitute, repair, or enhance bone health. Synthetic biomaterials are becoming increasingly prevalent in the medical field, and polymers are among the most commonly used materials due to their widespread availability, ease of processing, low cost, and great biocompatibility. High-density polyethylene (HDPE) is a polymer that has been widely used in medical applications due to its mechanical strength, chemical and biological resistance, and ease of processing. However, its use in biomedical implants is limited due to its lack of bioactivity and inability to promote cell growth and differentiation. To overcome this limitation, HDPE can be reinforced with bioactive ceramics such as hydroxyapatite (HA), which is a natural mineral found in bone tissue and is known for its excellent biocompatibility and bioactivity. The main objective of this project is to develop HDPE composites reinforced with micro/nano-sized HA particles for biomedical implant applications. The project will focus on three main aspects: fabrication, characterization, and simulation. The first aspect is the fabrication of HDPE composites reinforced with micro/nano-sized HA particles. The fabrication process involves the use of a twin-screw extrusion machine to mix the HDPE and HA particles at different concentrations. The mixing process will be performed according to the standard used to manufacture these types of materials. The resulting composites will be characterized for their microstructural morphology and mechanical properties. The second aspect is the characterization of the HDPE composites. The characterization will involve studying the mechanical properties of the composites, such as tensile, flexural, compression, and impact properties. These properties are crucial to ensure that the composites meet the required mechanical standards for biomedical implants. The microstructural morphology of the composites will also be studied using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The third aspect is the simulation of the mechanical behavior of HDPE composites under different loading and boundary conditions for various configurations. Finite element analysis (FEA) will be used to simulate the mechanical behavior of the composites. The simulations will be used to predict the mechanical properties of the composites and optimize their design for specific biomedical implant applications. Finally, HDPE composites will be manufactured using the latest additive manufacturing techniques such as 3D printing with a pellet extruder. The composites will be manufactured in various configurations for the most commonly used biomedical implant applications, such as hip and knee replacements.