The prickly pear cactus is prevalent in deserts and chaparrals; to thrive in such arid environments, it has developed various structural adaptations, such as its signature pads. Those thick, spongy pads store large quantities of excess water to last throughout the extensive chaparral droughts. One of the many key biological components responsible for holding the water is mucilage, a gel-like substance composed of hydrophilic polysaccharides, keeping the water in the pads. By developing a synthetic gel based on the properties of mucilage, scientists can create a material capable of storing large quantities of water and other hydrophilic liquids. It may be employed in daily settings as a new type of highly absorbent sponge or napkin, and even in feminine hygiene products.

The spines of cacti are leaves modified to reduce water loss: white to reflect sunlight and the spine shape to maximize surface area while minimizing volume. Living in the chaparral region, where rainfall is a scanty blessing, prickly pear cacti have adapted to source much of their water from fog. The pattern of the spines condenses water and directs the droplets’ traverse down to the cactus base, where specialized hairs absorb them. University of Southern California professor Yong Chen led a research study involving a 3D-printed structure inspired by cactus spines. They successfully mimicked the function of fog harvesting, paving the groundworks for a future technology that helps combat droughts and the lack of access to clean water. Additionally, the bioinspired spines can also serve as dehumidifiers as they can absorb water vapor.