Fig. 3.

Force and energy for the three experiments reported in Fig. 2. The force F exerted by the liquid on its substrate is measured with a force sensor and it is plotted as a function of the gap z normalized by the drop radius R₀. The interfacial energy U of the deformed drop is deduced from image analysis and it is also plotted as a function of z/R₀. Force and energy are normalized by 2πR₀γ and 4πR₀²γ, respectively. Data are full and black in the pressing stage, and empty and red in the lifting stage. (A) Force and energy for water on OTS-coated pillars, corresponding to the experiments in Fig. 2 A and B. (B) Force and energy for mercury on OTS-coated pillars (experiments in Fig. 2 C and D). Vertical dashed lines mark the boundaries of the mixed WC state observed during the W2C transition. (C) Force and energy for water on Glaco-coated pillars (experiments in Fig. 2 E and F).