Figure 8.

Water collection rates per unit surface area for single cylinder and cone, ungrooved and grooved, with homogeneous wettability at 0° and 45° inclinations. Objects at higher inclination have higher water collection rates, because gravity is facilitating movement of the droplets. There seem to be no difference between the water collection rates of the cylinders and cones, because gravitational force on the droplets seems to dominate Laplace pressure gradient in movement of the droplets. Grooves seem to add friction force to the movements of the droplets leading to lower water collection rate. However, grooves could be designed to minimize the friction effect.