Drop Retention Force as a Function of Drop Size

The force, f, required to slide a drop on a surface, is often considered to be a function of the drop size, V^1/3. Recent studies showed experimentally that f/V^1/3 is a decaying function of V [1]. However, these studies do not agree with Dussan's theory which predicts constant f/V^1/3 with V. Recent experiments that we performed using the novel Centrifugal Adhesive Balance [2], which allows maintaining constant the normal force for different lateral forces, reconcile (c.f. [3]) this apparent paradox and give a new and fascinating insight into the role of the surface rigidity to the drop retention force.

1. Yadav, P., Bahadur, P., Tadmor, R., Chaurasia, K., & Leh, A., Langmuir 2008, 24, 3181-3184
2. Tadmor, R., Bahadur, B., Leh, A., N'guessan, H. E., Jaini, R., & Dang, L., Phys. Rev. Lett. 2009, 103, 266101
3. Shanahan, M. E. R. & de Gennes, P-G., C. R. Acad. Sci. Paris 1986, 302, 517
Tadmor, R., Surface Science 2008, 602, L108–L111