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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.

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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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