Carbon Nano Tubes-Incorporated Smart Stents to Improve Mechanical Strength and Sensor Reliability

Atherosclerosis, a primary manifestation, involves the accumulation of plaques within artery walls, gradually constricting them. To address such constriction, a common intervention involves the insertion of various stent into the affected blood vessels. In addition, the material properties of the stent are very important because the stent inserted into the human body is a foreign substance. Ideally, substances that are absorbed into the body over time are desirable. However, the bioabsorbable polymer stents developed to date have limitations due to their low mechanical elasticity of the materials. Furthermore, if the stents inserted into the blood vessel have a function to detect the restenosis at an early stage, a simple drug treatment can solve the blockage. In this paper, we propose a 3D-printed polymer stent with high radial strength integrated with an LC-type sensor to monitor pressure changes in blood vessels in real time. The wireless pressure sensor is fabricated using the photosensitive polymer SU-8, with a supporting micro-pillar at the center of the capacitor to improve sensor performance, while the 3D-printed stent is mixed with CNT to enhance mechanical strength. The connection and operational principles of the wireless pressure sensor are assessed through an inductance-capacitance coupling circuit. This method aims to enhance early detection of restenosis, offering a promising solution in cardiovascular care.