Exploring the behaviour of water nanodroplet on a coplanar electrowetting-on-dielectric: a molecular dynamics approach

Hoi Kei Chan; Pui In Mak; Shirley W.I. Siu

Exploring the behaviour of water nanodroplet on a coplanar electrowetting-on-dielectric: a molecular dynamics approach

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Author(s): Hoi Kei Chan ¹ ; Pui In Mak ^{1, 2} ; Shirley W.I. Siu ¹
- Affiliations: 1: Department of Computer and Information Science, University of Macau, Avenida da Universidade, Taipa, Macau, People's Republic of China ;
  2: State-Key Laboratory of Analog and Mixed-Signal VLSI, Department of Electrical and Computer Engineering, University of Macau, Avenida da Universidade, Taipa, Macau, People's Republic of China
Source: Volume 12, Issue 7, July 2017, p. 486 – 489
DOI: 10.1049/mnl.2016.0824 , Online ISSN 1750-0443

This is an open access article published by the IET under the Creative Commons Attribution-NonCommercial License (http://creativecommons.org/licenses/by-nc/3.0/)

Received 04/01/2017, Accepted 01/03/2017, Revised 28/02/2017, Published 01/07/2017

Molecular dynamics simulation has been used to investigate the behaviour of a water nanodroplet on a hydrophobic surface under an applied electric field. The model system mimics a typical electrowetting-on-dielectric experiment of an open-plate coplanar electrodes system. Given the various strengths of the electrode-induced field, variations in contact angle of the droplet, hydrogen bonding and diffusion coefficient of the water molecules are disclosed. Their main findings are: (i) nanodroplet displays asymmetric electrowetting in contact angle measurement; (ii) water molecules and the entire droplet are slightly positively biased; (iii) more water hydrogen bonds are maintained in the positive side, in both the first and the second hydration layer to the surface; and (iv) water diffusion is higher in parallel to the surface than the normal direction.

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Exploring the behaviour of water nanodroplet on a coplanar electrowetting-on-dielectric: a molecular dynamics approach

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