fig3

Figure 3. Expansion performance of the phase-change balloon. (A) Schematic illustration comparing the inflating behavior of the balloon with and without axial pre-stretching. Pre-stretching eliminates undesired axial expansion while enhancing radial expansion during inflation; (B) Radial and axial expansion as a function of internal pressures under various pre-stretch. At a pre-stretch of 1.6, the balloon achieves optimal radial expansion; (C) Quantitative comparison of radial expansion and axial expansion of the balloon at 20 kPa internal pressure; (D) The maximum radial expansion and the retained mass during a heating-cooling cycle; (E) Output pressure exerted on surrounding vessels as a function of normalized vessel diameter, showing strong output pressure for angioplasty in small vessels; (F) Sequential images of the balloon’s expansion within a simulated silicone vessel with a modulus comparable to that of real blood vessels. For quantitative experimental data, error bars represent the standard deviation (SD), with n = 3 independent replicates.