Peristome-mimetic curved surface for spontaneous and directional separation of micro water-in-oil drops

Chuxin Li, Lei Wu, Cunlong Yu, Zhichao Dong, Lei Jiang

Research output: Contribution to journalArticleResearchpeer-review

43 Citations (Scopus)


Separation of micro-scaled water-in-oil droplets is important in environmental protection, bioassays, and saving functional inks. So far, bulk oil–water separation has been achieved by membrane separation and sponge absorption, but micro-drop separation still remains a challenge. Herein we report that instead of the “plug-and-go” separation model, tiny water-in-oil droplets can be separated into pure water and oil droplets through “go-in-opposite ways” on curved peristome-mimetic surfaces, in milliseconds, without energy input. More importantly, this overflow controlled method can be applied to handle oil-in-oil droplets with surface tension differences as low as 14.7 mN m−1 and viscous liquids with viscosities as high as hundreds centipoises, which markedly increases the range of applicable liquids for micro-scaled separation. Furthermore, the curved peristome-mimetic surface guides the separated drops in different directions with high efficiency.

Original languageEnglish
Pages (from-to)13623-13628
Number of pages6
JournalAngewandte Chemie - International Edition
Issue number44
Publication statusPublished - 23 Oct 2017
Externally publishedYes


  • bio-mimetic surfaces
  • peristome surface
  • separation
  • uni-directional transportation
  • water-in-oil drop

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