We then compared the performance of the star-shape polymeric photoinitiator to the commercial BAPO photoinitiator, phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, which is one of the most efficient molecular photoinitiators in DLP/SLA 3D printing. In this case, we prepared the resins with BAPO dissolved in NVP (8.0 wt%). The 3D printed objects exhibited similar tensile properties to those prepared with the "all-PEG" formulations (Figures and), which is likely because the semicrystalline PEG domains have much higher impact on the mechanical performance than the crosslinking sites due to the low amounts of photoinitiators and reactive diluents. tensile stress with Young's modulus of 3D printed specimens from different PEG macromonomers using BAPO (1.0 wt%) and NVP (8.0 wt%). The mechanical properties are expressed as mean ± s.d. (n = 5-7); e) The ETH logo and f) stent prototype printed with PEGDMA 8k and BAPO-PEG reverting to its original shape upon heating to ∼80 °C. The 3D printed objects (at 0 s) were deformed at ∼80 °C and fixed in that shape by cooling to -20 °C.