Passive sorting of emulsion droplets with different interfacial properties using laser-patterned surfaces

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68081731%3A_____%2F19%3A00504420" target="_blank" >RIV/68081731:_____/19:00504420 - isvavai.cz</a>

Result on the web

<a href="https://link.springer.com/article/10.1007%2Fs10404-019-2236-8" target="_blank" >https://link.springer.com/article/10.1007%2Fs10404-019-2236-8</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1007/s10404-019-2236-8" target="_blank" >10.1007/s10404-019-2236-8</a>

Result language

angličtina

Original language name

Passive sorting of emulsion droplets with different interfacial properties using laser-patterned surfaces

Original language description

We demonstrate passive sorting of emulsion microdroplets based on differences in their interfacial tension and contact angle. The sorted droplets are flowing inside a microfluidic channel featuring a shallow guiding track (depth similar to 0.6 mu m) defined by femtosecond laser micromachining in polydimethylsiloxane coating deposited on glass. Under these flow conditions, the droplets experience a confinement force that pulls them into the track. This force depends on the interfacial tension and the difference between the contact angles inside and outside the ablated track. The interplay between the confinement force, fluid drag, and wall friction then determines the trajectory of the droplet along the guiding track. We investigate experimentally the droplet trajectory as a function of droplet velocity and angle between the track and the channel axis and demonstrate precise control of droplet direction by adjusting the track angle. Moreover, we show that droplets of liquids with different interfacial tensions and contact angles travel different distances along the guiding track at a constant flow rate, which can be used for droplet sorting. We develop a theoretical model that incorporates the droplet position with respect to the ablated track, interfacial tension, and contact angles to predict the droplet trajectory under given experimental conditions. Thus, the dynamic behavior of the droplets leading to different guiding scenarios can be studied without the need of computationally expensive fluid dynamics simulations. The presented study paves the way for designing and optimizing new systems for advanced manipulation of droplets of different content using potentially reconfigurable guiding tracks.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

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OECD FORD branch

10305 - Fluids and plasma physics (including surface physics)

Project

—

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2019

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Microfluidics and Nanofluidics

ISSN

1613-4982

e-ISSN

—

Volume of the periodical

23

Issue of the periodical within the volume

5

Country of publishing house

DE - GERMANY

Number of pages

9

Pages from-to

65

UT code for WoS article

000463727700002

EID of the result in the Scopus database

2-s2.0-85064042775