-Carbon fibers
-Carbon fibers
Carbon fibers have been known at least since 1879. Carbon fibers often referred to as graphite fibers properties of these fibers are high tensile and compressive strength , stiffness, light weight , low coefficient of thermal expansion , good vibration damping , low abrasion and high fatigue resistance , biological compatibility and chemical inertness (70). Carbon fibers made from polyacrylonitrile precursor is successfully used in repairing damaged tendons and ligaments and in absorptive dressings .(71) Carbon fibers have good blood compatibility and are appropriate for applications with rigid structures ,but they are not suitable for structures that are thin or that require being flexed .Coating of polyamides , cellulose acetate ,silicone rubber ,and segmented polyetherurethane elastomers have been used for making composites of carbon , these composites make carbon more flexible .(4) Carbon fibers are successfully used as components of bone plats , hip join prostheses , ligaments and hydraulic for artificial heart implants. The use of carbon fiber reduces the weight of the limb to a level suitable for enfeebled geriatric patient and provides sufficient strength and durability to an active high weight amputee .(72) Carbon fiber reinforced ligament has been in clinical use for the treatment of interior cure for ligament damage and the resultant knee instability since braiding composite structure .(73)
