Mechanical Properties of Selective Laser Sintering (SLS) Additive Manufactured Chiral Auxetic Cylindrical Stent

The mechanical properties of the stent are of key importance to the mechanical integrity and performance reliability of stent-plaque-artery system, and an ideal stent should have good bending compliance, axial deformation stability, hoop strength and stiffness, larger radial expandable ability, etc. In this paper, innovative chiral stent designs with auxetic properties are proposed, and amplified stent sample is fabricated with SLS additive manufacturing technique. Firstly, through combining micro-CT tomography and image-based finite element analysis, the mechanical properties of as fabricated SLS stent are explored; Secondly, two series of stent samples are fabricated with SLS additive manufacturing techniques, and in-situ compression experiments are performed for studying the deformation mechanisms and auxetic mechanical behaviors of stents. Finally, effects of geometrical parameters on the tensile mechanical performance of these stents are studied with finite element analysis. The proposed chiral stent exhibits auxetic behaviors, and can be tailored through adjusting the unit cell design parameters, such as: struct numbers along circumferential directions, ligament lengths, and node radius.