The increasing development and application of ‘smart’ materials in other industries is opening up new possibilities in building design. ‘Digital Matter Intelligent Constructions’, undertaken by students at the Institute of Advanced Architecture of Catalonia, explores responsive materials such as hydrogel with the aim of improving building performance and embedding ‘intelligence’ into the built environment.

This project speculates on the thermodynamic processes that occur in a building and how these can be tackled passively with a class of materials called ‘hydrogel’. The term ‘hydrogel’ refers to a class of substances that absorb and retain 500 times their weight in water. Chemically, they are insoluble polymers of hydroxyethyl acrylate, acrylamide, polyethylene oxide, and others. As a cooling aid, they work by exposing absorbed water to a large surface area. Since the heat of vaporization of water is about 0.6 kilocalories per gram, a cooling effect occurs.

Taking this phenomenon as a starting point, they developed a ‘Hydroceramic’ building element. Their prototype – which works as an evaporative cooling device – reduces temperatures, increases humidity and is capable of lowering the temperature of the indoor environment by about 5 to 6 degrees. Its passive embedded intelligence makes its performance directly proportional to the heat in the outdoor environment – i.e. it cools more when it is more hot and doesn’t cool when no evaporation is occurring. These results were determined by an experiment set up to test the effect of hydrogel in reducing the temperature of a closed environment. At the same time, they established that clay is the best material to house hydrogel in the prototype. Clay, aluminum and acrylic were tested against a control, which helped determine that it is the porous nature of clay that aids the cooling properties of hydrogel in the best way.

The team estimate that this Hydroceramic could help save up to 28% of overall electricity consumption caused by the traditional air-conditioning and can be used as an low-cost alternative building technology as both clay and hydrogel are realtively inexpensive materials.