Scientific Reports (Sep 2021)

Water droplet can mitigate dust from hydrophobized micro-post array surfaces

  • Abba Abdulhamid Abubakar,
  • Bekir Sami Yilbas,
  • Al-Qahtani Hussain,
  • Ghassan Hassan,
  • Johnny Ebaika Adukwu

DOI
https://doi.org/10.1038/s41598-021-97847-7
Journal volume & issue
Vol. 11, no. 1
pp. 1 – 19

Abstract

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Abstract Water droplet rolling motion over the hydrophobized and optically transparent micro-post array surfaces is examined towards dust removal pertinent to self-cleaning applications. Micro-post arrays are replicated over the optically transparent polydimethylsiloxane (PDMS) surfaces. The influence of micro-post array spacing on droplet rolling dynamics is explored for clean and dusty surfaces. The droplet motions over clean and dusty micro-post array surfaces are monitored and quantified. Flow inside the rolling droplet is simulated adopting the experimental conditions. Findings reveal that micro-post gap spacing significantly influences droplet velocity on clean and dusty hydrophobized surfaces. Air trapped within the micro-post gaps acts like a cushion reducing the three-phase contact line and interfacial contact area of the rolling droplet. This gives rise to increased droplet velocity over the micro-post array surface. Droplet kinetic energy dissipation remains large for plain and micro-post arrays with small gap spacings. A Rolling droplet can pick up dust particles from micro-post array gaps; however, few dust residues are observed for large gap spacings. Nevertheless, dust residues are small in quantity over hydrophobized micro-post array surfaces.