Method for forming artificial vascular stent through 4D printing

Abstract

The invention discloses a method for forming an artificial vascular stent through 4D printing. The method comprises the following steps that (1) shape memory polymers or shape memory alloy serves as a transformable material unit, polymer materials or metal materials serve as a base body material unit, and an initial vascular stent configuration is designed; (2) the transformable material unit and the base body material unit are printed into a needed original 3D configuration with a direct fusion forming method, or a laser area selective fusion forming mode or a micro jet molten drip electromagnetic constraint forming mode is selected as a shape memory alloy printing forming mode to manufacture the vascular stent; (3) heat preservation and slow cooling are conducted on the original 3D configuration or the vascular stent obtained in the step (2); (4) performance tests are conducted on the formed vascular stent so that the vascular stent can meet using requirements, and thus the 4D printing forming of the artificial vascular stent is completed, wherein the performance tests include the mechanics performance test, the incentive transformation test and the medical performance test.

Description

【Technical field】 [0001] The invention belongs to the technical field of additive molding manufacturing, and in particular relates to a method for 4D printing and molding artificial vascular stents. 【Background technique】 [0002] Vascular stent refers to the placement of internal stents in the diseased segment on the basis of lumen balloon expansion to achieve the purpose of supporting the stenotic and occluded segment of the vessel, reducing the elastic retraction and reshaping of the vessel, and maintaining the smooth blood flow in the lumen. The internal stent also has the effect of preventing restenosis. The manufacture of vascular stents is a complex and delicate project. The size of the vascular stent itself is generally only 2mm-4mm in diameter, and the diameter of the metal wire is about 0.15mm-0.20mm. The diameter of the metal wire is required to be 0.05-0.09mm or even thinner for micro blood vessels. Artificial blood stents are difficult to process and manufactur...

AI Technical Summary

Problems solved by technology

However, due to severe work hardening and pseudoelasticity, conventional machining of shape memory alloys causes severe tool wear, time-consuming, and low-dimensional distortion

Traditional methods such as laser machining, water jet machining (WJM) and electrochemical machining (ECM) for machining, but these methods are limited by the complexity and mechanical properties of the material

Electric discharge machining (EDM) and wire cutting (WEDM) can process shape memory alloys with complex shapes and precise dimensions, but they cannot be processed for small-sized thin-walled components due to the difficulty in clamping

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