Tribological Characterisation of Biofluid Using Four Ball Experiment

This study presents the tribological characterisation of biofluid that uses plant-based oil namely sunflower oil and olive oil that has been blended with hyaluronic acid as an additive. Plant-based oil is a type fluid that is not harmful to humans and the hyaluronic acid helps the based fluid in absorption shock and distribution of forces. This project aims to measure the performance of this biofluid as an artificial synovial fluid in terms of its coefficient of friction, frictional torque and the wear scar diameter produced. Three different composition volumes of hyaluronic acid were used which are 0%, 5% and 10% in the fluid sample. This sample of biofluid is tested by using four ball tribological testing under one of the conditions which was wear preventive condition. To obtain the coefficient of friction and frictional torque for the biofluid by using the 3D Surface Measurement Systems, we measure the wear scar diameter produced at the ball bearings. The results acquired for this study are the average coefficient of friction and frictional torque that were directly proportional to the volume composition of additives. However, for the average wear scar diameter, it depends on the suitability of volume additives that have been added. Pure sunflower oil has the lowest coefficient of friction which is 0.065940. While, for average wear scar diameter, olive oil with 10% hyaluronic acid recorded the lowest value which is 0.64828mm. It shows that pure plant-based oil has the best lubricant ability which is producing lower coefficient of friction and frictional torque compared to it going to be blend with hyaluronic acid. This result of this project might give benefits to the medical engineering nowadays that related to the case that need the usage of artificial synovial fluid.