Unlocking the Full Potential of Jumping Condensation on Microstructured Surfaces.

Water condensation on superhydrophobic surfaces can generate spontaneous droplet jumping, enabling rapid condensate removal and improved thermal and mass transfer. Although this effect has been extensively demonstrated on densely packed nanostructures, the capability of microscale textures to support jumping condensation remains poorly understood. By systematically varying cone pitch within a series of microcone arrays with comparable cone geometries, we observe previously unreported spacing-dependent transition between jumping and non-jumping regimes. In the jumping regime, we identify a geometric threshold below which sub-10 µm droplets are rapidly removed, and above which jumping is suppressed, resulting in slower dynamics and larger departing droplets. In situ optical and environmental scanning electron microscopies provide evidence supporting a mechanistic interpretation of this transition: dense arrays favor full Cassie droplets, which depart cleanly, while wider spacing favors partial Cassie droplets that retain a localized wet region initiating new nucleation. Our findings establish a mechanistic link between the morphology of condensing microdroplets and the macroscopic jumping dynamics that govern performance in anti-fogging, water harvesting, and heat-transfer applications.