Additive manufactured cardiovascular scaffold integrated with SU-8 based wireless pressure sensor

Abstract

Herein, we proposed a SU-8 based wireless pressure sensor integrated with a polycaprolactone (PCL) based bioresorbable scaffold (BRS) for the detection of biological cues. The PCL-based BRS and pressure sensor are fabricated using a custom-designed additive manufacturing method and a modified photolithography technique. Firstly, we optimized the additive manufacturing fabrication parameters to realize the highly reliable scaffold with uniform strut width and thickness. Then, utilizing the optimized additive manufacturing conditions, we fabricated three distinct types of scaffolds, namely scaffold A, scaffold B, and scaffold C, each with a unique architecture. The preliminary characteristics of the fabricated scaffolds demonstrated that the scaffold A architecture exhibited superior properties, including 0.048 N mm-1 radial force, 1.64% foreshortening, and 14.1% recoil compared to the scaffolds B and C. The LC-pressure sensor is integrated into the PCL-based BRS using a water-soluble polyvinyl alcohol (PVA) adhesive layer. The reliability of the fabricated LC-pressure sensor is confirmed by measuring its change capacitance and resonance frequency at different applied pressures. The proposed LC-pressure sensor integrated PCL-based BRS is evaluated in a pressure range of 0 to 280 mmHg. The resonant frequency of the fabricated smart scaffold changed linearly according to the pressure change indicating the high reliability of the proposed smart scaffold. We anticipate that the proposed pressure sensor integrated with the biodegradable PCL-based BRS would be used for biomedical applications owing to their facile fabrication process and excellent sensitivity.