Optimization of Design Parameters of Biodegradable Magnesium-Based Alloy AZ31 Stent Using Response Surface Method

Recent years, biodegradable stents are becoming a trend. The development of stent with materials of biodegradable metal is concerned and the important thing to be analyzed is the stent's mechanical strength. This research is aimed to obtain optimal design parameters of a stent to meet ideal stent criteria such as von mises within the safe limit, minimum radial recoil, minimum longitudinal recoil, minimum foreshortening, and maximum inflated diameter. The expansion test of BT S<< parallel strut) stent made from magnesium alloy AZ31 is conducted by using finite element analysis (FEA) with Abaqus software in order to find the value of mechanical performance aspects such as von mises, radial recoil, longitudinal recoil, foreshortening, and inflated diameter. Simulations are conducted on stents with various thicknesses of 70μ m, 110μ m and 150 μ \mathrmm by using expansion pressures of 0.4 MPa, 0.6 MPa, dan 0.8 MPa. The simulation results are then optimized by using the response surface method. The design parameters of this research are stent thickness and an expansion pressure. The result shows that the optimal stent design is stent with a thickness of 116.06 μ \mathrmm and expansion pressure of 0.51 MPa. These optimal design parameters show von mises value of 411.56 MPa, radial recoil of 7.30, longitudinal recoil of-9.70, foreshortening of 43.50, and an inflated diameter of 3.34 mm. The results are considered acceptable as they meet the criteria of the ideal stent.