## 3 Results
### Support Structure Optimization  
As shown in Figure 4a, the standard geometry of an aortic stent investigated in this study is a filigree structure (periodic lattice) composed of struts with parabolic and inverted parabolic shapes. A small portion was picked and highlighted (Figure 4b) using the approximate measurements specified within the black box for clarification on the fundamental strut design. Struts of two different thicknesses, 0.5 mm and 1 mm, were also investigated to further extend the potential of the current study into real-world applications. If the build direction (BD) is 0 degrees or vertical, the L-PBF of an aortic stent with such a  
Figure 3: Particle size distribution of the as-received SS316L powder. Figure 2: (**a**) Standard tensile testing setup and (**b**) modified test setup, used for measuring the breaking load requirements of support structure designs. design necessitates a substantial amount of support structures [35]. The support structure needs for any other design direction with respect to BD can increase significantly [23; 35]. The manufacturing of a whole stent is thus unnecessary to determine an effective support structure configuration for the overhanging elements involved in this geometry, since it would require a large amount of time and material. It is worth noting that the component geometry for the inverted parabolic form, which is not an overhanging feature, does not demand a support structure. This is consistent with a study published by [PERSON] et al. [36], which demonstrated that the chosen geometry is an excellent illustration of a coronary stent. As a result, in the optimization process, only a single repeating strut indicative of the entire stent is required. The support structure design alone was considered inadequate for orienting the part with regard to the build platform during L-PBF. Hence, an additional cage structure (to enhance the manufacturability and avoiding distortion) as shown in Figure 4c,d was also integrated with all the support structure designs and was removed before further testing. For the stable manufacturing of the representative stent geometry using the cross support structure considered in the present study, minimization of the distance between the base plate was essential as well. Therefore, an additional support between the base plate and specimen bottom, as shown in Figure 4d, was also incorporated. This means that the total length of the cross support was much smaller in comparison with that of the line support. More details regarding the different support structure designs are given in the subsequent sections. Initially, four designs were explored in order to ascertain the best support structure. The four support structures were chosen based on the changes in the cross-section area exposed to the laser beam (melted layer), as shown in Figure 5. Figure 5 also includes additional information, such as the complete support structure design and the naming system followed for identifying the type of support. Based on the cross-section, the support structures are designated as rectangular, filled circle, cross, and line in the subsequent sections. The manufacturability of the parts was investigated for all four support structures as a preliminary assessment in the design and optimization process. The representative stent geometry with the filled circle and rectangular supports had good manufacturability. However, in comparison with the cross and line supports, both of these supports had higher material consumption and, as a result, longer production times. Even with the inclusion of a cage structure, as illustrated in Figure 6, the rectangular support structure  
Figure 4: (**a**) The representative geometry of an aortic stent: (**b**) the location of support structures highlighted using a black circle; initial design of the representative stent geometry and the associated support structure designs including the cage structure for (**c**) line support, (**d**) cross support.