The contact between liquid drops and hot solid surfaces is of practical importance for industrial processes, such as thermal spraying and spray cooling. The contact and bouncing of solid spheres is also an important event encountered in ball milling, powder processing, and everyday activities, such as ball sports. Using high speed video microscopy, we demonstrate that hydrogel drops, initially at rest on a surface, spontaneously jump upon rapid heating and continue to bounce with increasing amplitudes. Jumping is governed by the surface wettability, surface temperature, hydrogel elasticity, and adhesion. A combination of low-adhesion impact behavior and fast water vapor formation supports continuous bouncing and trampolining. Our results illustrate how the interplay between solid and liquid characteristics of hydrogels results in intriguing dynamics, as reflected by spontaneous jumping, bouncing, trampolining, and extremely short contact times.
Digital Object Identifier (DOI)
This work was supported by an Alexander von Humboldt postdoctoral fellowship (J.T.P.), the EU’s Horizon 2020 research and innovation program No. 722497—LubISS (D.V.), and the ERC advanced grant SUPRO 340391 and ITN COWET (H.-J.B.).
The data obtained and analyzed that support the findings of this study are available upon reasonable request. Supplementary Information accompanies this paper at doi:10.1038/s41467-017-01010-8.
Pham, Jonathan T.; Paven, Maxime; Wooh, Sanghyuk; Kajiya, Tadashi; Butt, Hans-Jürgen; and Vollmer, Doris, "Spontaneous Jumping, Bouncing and Trampolining of Hydrogel Drops on a Heated Plate" (2017). Chemical and Materials Engineering Faculty Publications. 38.
41467_2017_1010_MOESM2_ESM.pdf (95 kB)
Description of Additional Supplementary Files
41467_2017_1010_MOESM3_ESM.mp4 (474 kB)
Supplementary Movie 1
41467_2017_1010_MOESM4_ESM.mp4 (2642 kB)
Supplementary Movie 2
41467_2017_1010_MOESM5_ESM.mp4 (1883 kB)
Supplementary Movie 3
41467_2017_1010_MOESM6_ESM.mp4 (4198 kB)
Supplementary Movie 4
41467_2017_1010_MOESM7_ESM.mp4 (1426 kB)
Supplementary Movie 5
41467_2017_1010_MOESM8_ESM.mp4 (2002 kB)
Supplementary Movie 6
41467_2017_1010_MOESM9_ESM.mp4 (2156 kB)
Supplementary Movie 7
41467_2017_1010_MOESM10_ESM.mp4 (3273 kB)
Supplementary Movie 8
41467_2017_1010_MOESM11_ESM.mp4 (245 kB)
Supplementary Movie 9
41467_2017_1010_MOESM12_ESM.mp4 (2783 kB)
Supplementary Movie 10