Leidenfrost droplets can be considered as soft engines capable of directly transforming heat into mechanical energy. Despite remarkable advancements in understanding the propulsion of Leidenfrost droplets on asymmetric structures, the complex dynamics of droplets in enclosed structures is not fully understood. To address this fundamental gap, we investigated the dynamics of Leidenfrost droplets restricted by metal disks. The disk alters the accumulation and release of the vapour generated by the droplet, and substantially changes its dynamic characteristics. Our experiments reveal the formation of oscillating multi-lobed structures when restricting the droplet within a disk. In comparison, patterning offset radial grooves on the surface of the disk rectifies the vapour flow and facilitates the self-propulsion of the droplet along the edge of the disk. Our work offers opportunities for developing soft and short-living actuators, which can operate at high temperatures.
Bibliographical noteFunding Information:
E. P. acknowledges NHMRC for funding ‘The Australian Centre for Electromagnetic Bioeffects Research’ (NHMRC CRE APP1135076). K. K. acknowledges the Australian Research Council (ARC) ARC for Discovery Grants (DP170102138 and DP180102049).
E. P. acknowledges NHMRC for funding ?The Australian Centre for Electromagnetic Bioeffects Research? (NHMRC CRE APP1135076). K. K. acknowledges the Australian Research Council (ARC) ARC for Discovery Grants (DP170102138 and DP180102049).
© The Royal Society of Chemistry 2020.
ASJC Scopus subject areas
- Condensed Matter Physics