Symmetry when wet: A student’s building material changes shape in the rain

When a pine cone gets wet, its scales swell and close to protect its seeds from dispersing during unfavorable conditions. Warm, dry weather is better for spreading the winged seeds far enough to give a new tree space to grow, so that’s when the pine cone opens up. Royal College of Art student Chao Chen noticed this phenomenon and decided to create a building material that imitates nature.

“Each pine cone has two layers,” Chen tells Co.Design. “When it gets wet, the outer layer elongates more than the inner layer and closes in on itself. As a designer, this was very important for me.” His laminate is made of fabric, thin film, and veneer. When wet, the veneer’s fibers swell and alter the shape of the material.

His project, Water Reaction, is made of three prototypes that employ his idea. First, he created a shelter with laminated tiles that open when it’s sunny then bend and close if it starts to rain. Chen’s second idea is a “water-reacting” architectural surface that is suited to rainy areas, like Portland. The tiles also bend when wet but instead open into a geometric shape, revealing the colored surface below, brightening up the dreary day.

The third project isn’t for buildings but works on the same principle. It’s a strip of material that offers gardeners an instant idea of how their plants are faring; the red side shows when the strip stands straight up, indicating the soil is dry, while the blue side shows when the strips bends, meaning there’s enough water.

Chen says he still has some work to do before any of his projects get out of the prototype phase. “The material needs to be more durable. I need to test how many times it can get wet, how it can deal with heavy winds.”