An experimental investigation on shape memory polymer and metallic stents under bending and radial compression

Abstract

In this paper, shape memory polymers (SMPs) are fabricated by blending Polyurethane (PU) and Polycaprolactone (PCL). A novel method is used to make tubular stents using this blend. The solution coating method is applied to fabricate the SMP stent samples with a non-groove structure. Some metallic commercial stents made of the platinum-chromium alloy are used to compare SMP stents’ the mechanical properties with metal ones. According to the stents’ functionality, two mechanical tests, i.e., radial compression and three-point bending, are conducted in a range of body temperature. According to the mechanical test results, the tubular polymer stent shows a lower strength under the radial forces and a higher strength under the bending forces than to their metal counterparts. However, the mechanical properties of the SMP stents are in the range of metal stents. Thus, the PU/PCL SMP blend can be a promising candidate to be used as the coronary artery stents.

Development of an Actuator for Translatory Movement by Means of a Detented Switching Shaft Based on a Shape Memory Alloy Wire for Repeatable Mechanical Positioning

“…Shape memory actuators are well known and used in several fields such as automotive, aviation, robotics and medicine. In the field of medical technology, shape memory alloys (SMAs) are primarily used in form of stents as a medical implant for keeping vessels or hollow organs open [1,2]. For several application fields, SMA actuators have drawn attention as a possible alternative to state-of-the-art actuator systems due to their high energy density and their potential for miniaturization of actuator systems [3][4][5][6][7].…”