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Effect of gravity in the Cassie-to-Wenzel transition on a micropatterned surface

Published online by Cambridge University Press:  13 December 2019

Arash Azimi  and
Ping He Open the ORCID record for Ping He [Opens in a new window]
Arash Azimi
Affiliation:
Department of Mechanical Engineering, Lamar University, Beaumont, TX77710, USA
Ping He*
Affiliation:
Department of Mechanical Engineering, Lamar University, Beaumont, TX77710, USA
*
Address all correspondence to Ping He at phe@lamar.edu
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Abstract

When the Cassie–Baxter and Wenzel states coexist for a liquid droplet on a micropatterned surface, the Cassie-to-Wenzel transition takes place if the energy barrier is overcome. Although multiple metastable states coexist due to the micropattern, this paper presents a simple Cassie-to-Wenzel transition of a 2 µL water droplet on a particular micropillared surface: When the droplet is gently deposited above the surface, it equalizes to the Cassie state at zero gravity; however, it transitions to the Wenzel state at the terrestrial gravity, in which the gravitational potential energy overcomes the energy barrier between the Cassie and Wenzel states.

Type
Research Letters
Information
MRS Communications , Volume 10 , Issue 1 , March 2020 , pp. 129 - 134
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Copyright
Copyright © Materials Research Society 2019

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