Fig. 2: Analysis of water absorption-induced expansion behavior in porous elastomers and the changes in mass and dimension during the expansion process.
From: Bioinspired hydrophobic pseudo-hydrogel for programmable shape-morphing
a Schematic of pure elastomer and SEM (Scanning Electron Microscope) image of a smooth cross-section. b Schematic of a porous elastomer and SEM image of a smooth cross-section. c The Optical picture of a pure elastomer sample in its original state after water immersion. d The Optical picture of absorption-induced expansion behavior of a porous elastomer sample after immersion in water. e Schematic during the wetting stage with large amount of air stored in the pore structure of HPH. f Schematic during the wetting stage with rarefied air entrapped in the pore structure of HPH. g Schematic during the expansion stage with rarefied air entrapped in HPH. h The curves of mass and volume change versus time of porous elastomer after immersed in water. i The expansion ratio versus time curves of porous elastomer with an average pore size of approximately 60 μm. Results are expressed as the mean ± SD for independent replicates (n = 3).
