We present experimental evidence that drop breakup is caused by thermal noise in a system with a surface tension that is more than 106 times smaller than that of water. We observe that at very small scales classical hydrodynamics breaks down and the characteristic signatures of pinch-off due to thermal noise are observed. Surprisingly, the noise makes the drop size distribution more uniform, by suppressing the formation of satellite droplets of the smallest sizes. The crossover between deterministic hydrodynamic motion and stochastic thermally driven motion has repercussions for our understanding of small-scale hydrodynamics, important in many problems such as micro- or nanofluidics and interfacial singularities. © 2006 The American Physical Society.
Materials by design for sustainable solutions in the energy, medical, transport, and engineering sectors
