Shapeshifting building material that reacts to rain

A study at the Royal College of Art, conducted by Chao Chen, designed a building material that changes shape in response to rain. Chen picked up a pine cone after walking through the park on a rainy day and noticed that pine cones react to water by closing the outer shell.  

“Each pine cone has two layers,” Chen says. “When it gets wet, the outer layer elongates more than the inner layer and closes on itself.” Inspired by the pine cone’s anatomy, Chen created a laminate, a thin film, and a veneer that reacts to water similar to the way a pine cone does. The fibers expand perpendicularly, elongating and curving the material. 

In a new project, Chen was able to test this material through a “water-reacting shelter” covered in these laminated tiles. The tiles stay open when the weather`s sunny, but close and stack on top of each other whenever it rains.  

Chen says that “users will feel like they’re standing under some sort of tree, enjoying the sunshine. When it rains, all the tiles will be closed to cover the whole surface of the shelter.” 

Inspired by the pine cone design, Chen also created a water detector. The water detector uses a strip of material with blue and red colouring on different sides to senses the amount of moisture in the soil. By either remaining limp and showing the blue side or stiffening up revealing the red side, Chen’s creation is able to indicate when it’s time to water your plant.  

The initial design was simply a prototype, however, Chen is working hard to test and perfect the material.