Fig. 5: Vertical adhesion force measurements.
From: Probing surface wetting across multiple force, length and time scales
a Schematic of the scanning droplet adhesion microscope (SDAM). b Force curve on a superhydrophobic surface during (i) approach, (ii) contact, (iii) maximum compression force, (iv) retraction, and (v) detachment. c Plot showing snap-in and adhesion forces as a function of advancing and receding contact angles, respectively, for various samples measured with SDAM42,43,97,98 and force tensiometers96. The error bars for contact angles are due to uncertainty in the baseline location, while the error bars for force measurements are due to sensor noise in SDAM and tensiometer. d Adhesion force can alternatively be measured with an elastic cantilever. e Force curve for an oil droplet (submerged in water) on a hydrated polymer brush surface. f Plot of normalized adhesion force vs. normalized velocity for oil droplets on hydrated polymer brushes (submerged in water)33 and for water droplets on a superhydrophobic surface (in air). SDAM wetting force maps for (g) biological samples42, (h) flat coated silicon, and (i) bottom of a 3D-printed bowl98.
