Topology optimization for polymeric stent.

The topological optimization technique is an effective way to provide the optimal design for the polymeric stents. Conventional topology optimization procedure for polymeric stent was all based on classical theory of elasticity and usually only used one layer of shell element in structural analysis. It will lead to that the simulated stent structural stiffness deviates from the real case. Thus, a novel 3D topology optimization procedure based on Cosserat theory is proposed to maximize the radial stiffness of polymeric stent by taking advantage of the size effect of polymer materials. The stent structural analysis is implemented by a proposed high-order Cosserat spectral element method, ensuring that the analysis and optimization results can achieve high accuracy with only one layer of element for the polymeric stent. Cosserat characteristic length of polymeric material is obtained by the three-point bending test, and a parametric analysis is conducted to identify the effect of Cosserat characteristic length, volume fraction, and unit cell size on the optimized stent structure, and the optimal results based on the Cosserat theory are compared with the conventional ones. It is found that the size effect has a significant impact on the topology optimization results of polymeric stent. Compared with conventional commercial stent, the optimal polymeric stent obtained by the Cosserat theory has lower volume fraction and higher radial stiffness. Our results provide an effective way to further improve the mechanical performance of the polymeric stent. [ABSTRACT FROM AUTHOR]