UPenn researchers copied elephant skin in porous cement tiles; a mockup home stayed near 32°C versus 42°C and 52°C with commercial stucco surfaces

An elephant standing under the African sun has no sweat glands, no air conditioners, and yet it manages to stay cool. Elephants face heat differently because they lack sweat glands and rely on other cooling mechanisms: a network of cracks in their skin that traps water and releases it slowly through evaporation. A group of architects and materials scientists at the University of Pennsylvania has now built that same mechanism into a cement tile. According to a study titled “Elephant-Skin-Inspired Porous Cementitious Tiles with Programmable Crack Networks for Passive Cooling,” published in the peer-reviewed journal Advanced Materials in April 2026, a team of researchers from Penn's Weitzman School of Design and School of Engineering developed a cement tile filled with strategically engineered cracks designed to trap and gradually evaporate water. In a benchtop model of a building roof, the tile held a temperature of approximately 32°C (about 90°F), while two commercial stucco controls, one with cracks and one without, rose to approximately 42°C and 52°C respectively under the same infrared heating and watering cycle

How the engineered cracks work

This is the harsh reality about most exterior buildings materials like stucco, bricks, vinyl siding, were never created with self-cooling in mind. They just soak up all the heat during the day and keep on emitting it even after the sun has gone down, which is one of the reasons why cities often feel hot even after dark. We have sealed our buildings tight and turned to air conditioning, but it only works as long as our power grids are functional and the electric bills do not explode.

As explained by a Penn Today coverage of the 2026 study, professors Dorit Aviv from architecture and Shu Yang from materials science began from the observation that elephants rely on the wrinkles and cracks in their skin to hold water and let it evaporate slowly, cooling them over time. The researchers describe their tile not as an imitation of sweating, but as an alternative evaporative-cooling strategy borrowed from an animal that, precisely because it cannot sweat, evolved a different way to manage heat through its skin. The question the team set out to answer was whether concrete could be engineered to do something similar.

Turning a flaw into a feature

Normally, any form of cracking is undesirable as it means failure in construction. However, Yang et al. applied a novel method of creating a crack structure. They blended regular Portland cement with diatomaceous earth, a porous material produced from fossilized algae, then dried it in a lab setting to form the cracks in a consistent honeycomb shape.

The cracks function as irrigation channels that guide the water sideways across the tile, and through capillary action, the same wicking effect that lets a paper towel or a sponge draw liquid upward against gravity, even somewhat uphill on sloped surfaces, while the micro-porosity of the material soaks up each droplet in less than 50 milliseconds before the water could bead up and drain. Through the hexagonal structure, water moves in zigzag patterns over the surface rather than draining vertically, and according to the scientists, this helps maintain the evaporation and cooling effect of the tile for up to 20 hours after each water application.

Heat, energy use, and why the timing matters

Extreme heat is one of the most dangerous weather threats right now in the United States.According to the CDC's most recent complete annual data, heat-related deaths reached 2,394 in 2024, following 2,415 in 2023, both well above the roughly 700-per-year average recorded from 2004 to 2018, reflecting a sharp rise over the past decade. Factor in that buildings account for 40 percent of the primary energy consumption in the US, a fair portion of which goes toward air conditioning, and the DE-cement that does not require electricity becomes more than a novelty; it’s a potential piece of infrastructure.

The researchers have shown that the diatomaceous-earth cement mixture can be applied to large panels using a standard hopper gun, and Yang has since founded a company, Minerava, to develop the material for commercial use. According to Minerava's own materials, the approach has so far been validated at the scale of meter-sized 3D-printed concrete components, with a longer-term production target, not yet reached, of 100,000 cubic meters of material supplied annually. It remains a laboratory- and prototype-stage material rather than a finished commercial product. Yet in an era where insurance premiums and energy bills keep going up whenever we break another temperature record, a passive cooling material validated in a peer-reviewed study represents a meaningful step, distinct from the many products marketed loosely as "space-grade" or climate-resilient without comparable evidence behind them.