Understanding Self-Propelled Droplet Jumping to Enhance Condensation Heat Transfer

Understanding Self-Propelled Droplet Jumping to Enhance Condensation Heat Transfer

Scientific Achievement
Top: Scanning electron micrographs of nanostructured surfaces with 400 nm or 700 nm tall pillars with diameters ranging from ~35 nm to ~350 nm. Bottom: High-speed microscopy of jumping droplet. (hi-res image)

The critical size of jumping droplets is directly correlated with the topography of the underlying nanostructure.

Significance and Impact

Self-propelled, out-of-plane jumping of micro-droplets reduces the size of dropwise condensate by three orders of magnitude, which maximizes condensation heat transfer.  

Research Details

- Superhydrophobic silicon nanopillars were fabricated using dewetted platinum films as non-lithographic etch masks.
- The critical (minimum) size of jumping-droplet condensation was observed using high-speed microscopy.
- A model accurately correlates this size to the underlying topography
- Scalable superhydrophobic surfaces also aid in meltwater removal in defrosting.
 

M.D. Mulroe, B.R. Srijanto, S. F. Ahmadi, C.P. Collier, and J.B. Boreyko, "Tuning superhydrophobic nanostructures to enhance jumping-droplet condensation," ACS Nano 11 (8), 8499-8510 (2017).  DOI: 10.1021/acsnano.7b04481

K.M. Murphy, W.T. McClintic, K.C. Lester, C.P. Collier, and J.B. Boreyko, "Dynamic defrosting on scalable superhydrophobic surfaces," ACS Appl. Mater. Interfaces (28), 24308-24317 (2017). DOI: 10.1021/acsami.7b05651

CNMS Researchers

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