Migration of droplets on a conical fiber

In arid climates, nature has developed an efficient method of harvesting water from the air. Organisms, like cacti, are covered in a multitude of needle-like conical spines. Water droplets that condense on the tip of the fiber are spontaneously driven toward the base by Laplace pressure. The changing curvature of the conical shape is the mechanism responsible for the motion. We examine the effect of geometry on the droplet movement and compare the motion of multiple droplets on a conical glass fiber to that of a single droplet.