Video: Water droplets pop like popcorn off geckos’ skin

Condensation? Like water off a gecko’s back (Image: Kristian Bell/Getty)

They are famed for being able to effortlessly stick to walls and ceilings, but geckos have now been found to perform another cool trick. Slow-motion video footage has shown naturally formed water droplets launching themselves away from a gecko’s body like popping popcorn.

The phenomenon has been seen previously on some insects and artificial surfaces, but never on geckos. Dubbed “geckovescence”, it is caused by a dense array of minuscule, hair-like structures called spinules, which cover the bodies of many geckos. This scaly microstructure is thought to be unique to these animals and seems to help them shed water.


Gregory and Jolanta Watson at the University of the Sunshine Coast in Queensland, Australia, and their colleagues observed small water droplets condensing on the scales of the gecko Lucasium steindachneri in humid conditions. Instead of forming a thin film on the skin, the drops grew and clumped together, aided by the spinule architecture. When they became large enough, they self-propelled off the surface as a result of energy changes during the clumping process.

Water cannon

Most drops are launched far enough away for them to be removed from the vicinity of the skin by external forces, such as gravity or wind. Any drops that do not initially escape return to the skin and can combine with other drops to promote the jumping process. Jolanta Watson reckons that this phenomenon might have evolved to prevent moisture-loving microbes from thriving on the lizard’s skin, and it might also work as a self-cleaning mechanism.

In future, the effect could be harnessed for developing novel water- and bacteria-repellent surfaces, or water-harnessing surfaces. “We are now focusing on other interesting properties of the skin nanostructuring which, combined with the jumping droplets phenomena, may find applications in the health and other materials industries,” says Jolanta Watson.

Journal reference: Journal of the Royal Society Interface, DOI: 10.1098/rsif.2014.1396