Drops pushing by Marangoni forces

Numerical simulations and laboratory experiments show that Marangoni effect s are responsible for a pushing force on a droplet interacting with a solid wall in the presence of a temperature gradient. The results clarify questi ons of interest in the field of material science, in particular, they may p rovide some explanation for the minority phase separation observed during s olidification processes under microgravity conditions. (C) 2001 American In stitute of Physics.