4D printing of magneto-responsive shape memory nano-composite for stents

Abstract

This study focuses on the 4D printing simulation technique of magneto-responsive shape memory nanocomposite stents. A nanocomposite material was created by incorporating polycaprolactone, a shape memory material, with Fe₃O₄ to enhance magnetic responsiveness and stiffness. Tensile tests were conducted, and the material properties were applied to finite element analysis. Shape memory experiments were also performed to measure the temperature at which shape memory progression occurs due to magnetic response. In the 4D printing simulation, different coefficients of thermal expansion and the measured temperatures were reflected in the sections where shape memory is activated to implement shape memory behavior. The specimen simulation confirmed shape memory behavior progressing from 145 degrees to 3 degrees, while the stent simulation demonstrated satisfactory expansion to a radius of 3 mm. This study proposes a controllable method for implementing shape memory considering temperatures induced by magnetic response, showing potential for various medical device applications.