Transport of a micro liquid plug in a gas-phase flow in a microchannel

Yutaka Kazoe, Takumi Matsuno, Ippei Yamashiro, Kazuma Mawatari, Takehiko Kitamori

Research output: Contribution to journalArticlepeer-review

5 Citations (Scopus)


Micro liquid droplets and plugs in the gas-phase in microchannels have been utilized in microfluidics for chemical analysis and synthesis. While higher velocities of droplets and plugs are expected to enable chemical processing at higher efficiency and higher throughput, we recently reported that there is a limit of the liquid plug velocity owing to splitting caused by unstable wetting to the channel wall. This study expands our experimental work to examine the dynamics of a micro liquid plug in the gas phase in a microchannel. The motion of a single liquid plug, 0.4-58 nL in volume, with precise size control in 39- to 116-m-diameter hydrophobic microchannels was investigated. The maximum velocity of the liquid plug was 1.5 m/s, and increased to 5 m/s with splitting. The plug velocity was 20% of that calculated using the Hagen-Poiseuille equation. It was found that the liquid plug starts splitting when the inertial force exerted by the fluid overcomes the surface tension, i.e., the Weber number (ratio of the inertial force to the surface tension) is higher than 1. The results can be applied in the design of microfluidic devices for various applications that utilize liquid droplets and plugs in the gas phase.

Original languageEnglish
Article number423
Issue number9
Publication statusPublished - 2018
Externally publishedYes


  • Droplet
  • Microchannel
  • Microfluidics

ASJC Scopus subject areas

  • Control and Systems Engineering
  • Mechanical Engineering
  • Electrical and Electronic Engineering


Dive into the research topics of 'Transport of a micro liquid plug in a gas-phase flow in a microchannel'. Together they form a unique fingerprint.

Cite this