Material: Thermochromic paint
Functions: Cooling, communicating helpful messages during heat stress; water exchange
Application: As paint on large areas in the city, e.g., public squares
Welcome to the »Thermochromic Sponge City«! This speculative idea came to life in a workshop group made up of researchers, artists, and city dwellers. They came up with the idea for a special asphalt that is permeable to water. In the future, this water-permeable asphalt would enable a constant exchange between surface water and groundwater: Rainwater could seep away and the local water balance would be sustainably supported. Additionally, this asphalt could be coated with thermochromic pigments, which change color at high temperatures. The color change could cool large areas (e.g., public squares). In addition to the cooling effect, heat stress warnings could be placed under the sealant to raise awareness of the health effects of heat stress.
»We finally decided on a proposal linked to asphalt. We expect that the city of the future in 2050 will already have been developed as a sponge city and will no longer retain so much heat. Nevertheless, there will probably still be asphalt – it won’t disappear in 30 years. And this asphalt will change color when it’s too hot. We call this the ›Thermochromic Sponge City‹. This function is particularly important for public squares. The color change then leads to a cooling effect. In this way, heat and water are stored.«