Fig. 2
From: Spontaneous jumping, bouncing and trampolining of hydrogel drops on a heated plate
Hydrogel drop jumping due to vaporization of the meniscus. a Time snapshots of the jumping of a 25 kPa hydrogel drop (Supplementary Movie 3). The meniscus is clearly visible in the first image and is completely gone 0.5 ms later after meniscus explosion. The 1.5 ms image illustrates the upward motion of the hydrogel. Scale bar: 0.5 mm. b Evolution of a 2 kPa hydrogel drop jumping after burning. Bubbles first form underneath the drop (Supplementary Movie 4). The hydrogel drop attempts to jump (664 ms), but adhesion by fibrils holds it back. The drop remains on the surface and rapid vibrations are observed (1133–1139 ms). The polymer fibrils start to burn away and the drop is released from the surface (2020 ms). Scale bar: 1 mm. Illustrations for the proposed mechanism of (c) jumping of the 25 kPa hydrogel in part (a) and (d) cavity formation and burning of the 2 kPa hydrogel in part (b)
