Vascular phantoms are artificial vessel models that provide controlled and repeatable environments for medical research, imaging validation, device testing, surgical planning, and training. To improve their physiological relevance, these phantoms should not only reproduce vascular geometry, but also show mechanical behaviour that is representative of blood vessels. In particular, small-scale compliant vascular phantoms should be able to deform under pressure-driven flow. However, fabricating small open channels from soft materials while maintaining geometrical accuracy, tunable stiffness, and measurable compliance remains challenging.

This thesis investigates the fabrication and experimental characterization of small-scale flexible vascular phantoms created using masked stereolithography 3D printing. Straight cylindrical channels were printed using Elastomer-X resin with different lumen diameters and wall thicknesses to determine a printable geometry range. The geometrical accuracy of the printed channels was evaluated using microscopy, while the internal lumen geometry was further inspected using ink-filled channels. Tensile tests were performed to determine the Young's modulus of the printed material under different exposure and post-curing conditions. By varying the printer exposure time and UV post-curing duration, different stiffness configurations were obtained.

The pressure-flow behaviour of the printed channels was investigated using water as the working fluid. Baseline measurements were used to correct for pressure losses in the setup, after which the channel-only hydraulic resistance was calculated. The effective diameter was then estimated from the hydraulic resistance using the Hagen--Poiseuille relation. The results showed that a lumen diameter of 0.7~mm with a wall thickness of 0.25~mm could be printed as the smallest consistently open channel suitable for flow experiments. Tensile testing showed that the Young's modulus could be tuned between approximately 1.05 and 1.25~MPa by changing the fabrication conditions. Pressure-flow measurements showed a decrease in hydraulic resistance with increasing mean pressure for several channels, corresponding to an increase in effective diameter. The softer channels generally showed a larger relative effective diameter increase than the slightly stiffer channels.

These results demonstrate that masked stereolithography can be used to fabricate small-scale flexible vascular phantoms with tunable stiffness and measurable pressure-dependent behaviour. Although the effective diameter was determined indirectly and uncertainties remain due to local lumen narrowing, measurement noise, and baseline correction, the study provides an important experimental validation step towards compliant 3D printed vascular phantoms for pressure-flow applications.