Theory 22/Interfacial Science
Adhesion Is a Capillary Ratio
The claim
The adhesion between a soft particle and a surface is set by the ratio of capillary length to elastic deformation length, so humidity changes adhesion only past a threshold.
01The mechanism
A capillary bridge adds a force, but its effect depends on whether the resulting deformation is large enough to grow the contact; the ratio sets that feedback.
02Predictions
- P1Adhesion should jump past a humidity threshold.
- P2Stiffer particles should be less sensitive.
03Refutation
Adhesion scaling smoothly with humidity would remove the ratio.