We investigated the organization of micrometric hydrophilic beads (glass or basalt) immersed in Leidenfrost drops. Starting from a large volume of water compared to the volume of the beads, while the liquid evaporates, we observed that the grains are eventually trapped at the interface of the droplet and accumulate. At a moment, the grains entirely cover the droplet. A liquid marble is obtained using hydrophilic grains! Leidenfrost droplet allows to obtain perfect non-wetting conditions which can be used to organise particles.
L.Maquet, P.Colinet and S.Dorbolo, Organization of microbeads in Leidenfrost drops, Soft Matter 10, 4061-4066 (2014) – PDF