Printing parameter optimization of stent length accuracy by using response surface methodology (RSM)

The demand for coronary artery stents keeps rising every year with a higher quality, lower cost, faster and economical process. Due to its availability relatively low-cost price and adaptability, Polylactic-acid (PLA) has been identified as an ideal material for biodegradable stents. Previously, laser micromachining was widely used for processing coronary stent but this manufacturing process required high investment. Apart from that, this process was unpractical and unfeasible to be machined with certain material and complex design. Alternatively, FDM 3D printing emerges as a system for producing stent and gained attention for its low cost, high reliability, simple operation, flexibility and has shown potential as promising solutions in stents fabrication. Stent length is one of the key aspects in stents manufacturing. In this work, optical microscope is used to measure the stent characterizations while processing parameter optimization was performed by using Response Surface Methodology (RSM). Printing orientation affects the stent length dimensional accuracy. Both XY and ZX are capable to develop PLA stents but XY-orientation is the ideal printing orientation as it provides good dimensional precision for stent characterizations and a lower risk for the structure and geometry to be sagging.