Laboratory layered latte.

TitleLaboratory layered latte.
Publication TypeJournal Article
Year of Publication2017
AuthorsXue, N, Khodaparast, S, Zhu, L, Nunes, JK, Kim, H, Stone, HA
JournalNat Commun
Date Published2017 Dec 12

Inducing thermal gradients in fluid systems with initial, well-defined density gradients results in the formation of distinct layered patterns, such as those observed in the ocean due to double-diffusive convection. In contrast, layered composite fluids are sometimes observed in confined systems of rather chaotic initial states, for example, lattes formed by pouring espresso into a glass of warm milk. Here, we report controlled experiments injecting a fluid into a miscible phase and show that, above a critical injection velocity, layering emerges over a time scale of minutes. We identify critical conditions to produce the layering, and relate the results quantitatively to double-diffusive convection. Based on this understanding, we show how to employ this single-step process to produce layered structures in soft materials, where the local elastic properties vary step-wise along the length of the material.

Alternate JournalNat Commun
PubMed ID29234036
PubMed Central IDPMC5727143