Figure 4. Evaporation rates at the final stages.

Evaporation dynamics of water capillary bridges whose volumes gradually decrease with time from characteristic volumes of v₀ ~ 240 fL. The volume changes are described as v^2/3 = v₀^2/3 – (⅔) k_wt and v → 0 as t → t_f, where k_w is a constant and is experimentally set as ~ 248 fL^2/3/s for water. The evaporation rate expression of −dv/dt = k_wv^1/3 is similar to the sessile drop evaporation law²⁰,²⁴, but the evaporation rate for a bridge is slower than that for a hemisphere sessile drop with identical surface area. The error bars were determined by the repetition of measurements for each sample.