As global temperatures rise and water scarcity worsens, a nanoengineered paint developed by researchers in Australia aims to tackle both — with the stroke of a brush.
For University of Sydney scientists Chiara Neto and Ming Chiu, these growing pressures sparked an idea: a rooftop coating that could cool buildings and harvest water from the air, according to CNN.
That work evolved into startup Dewpoint Innovations, founded in 2022 with ambitions beyond cooling paint to a broader rethink of how infrastructure is designed: If rooftops across a city could reflect heat and collect water, they could become part of the climate solution.
In a warming world, cities are becoming heat traps. Concrete and rooftops absorb the sun’s energy, raising temperatures, leading to what’s known as the urban heat island effect — where cities experience higher temperatures.
That is the first challenge Dewpoint Innovations is targeting: “Our paint will significantly reduce the heat load the sun puts on cities,” said Chiu, co-inventor and chief technology officer at Dewpoint Innovations.
To achieve that effect, the specially engineered nanomaterials use a process called passive radiative cooling to reflect most of the sun’s energy and release heat back into the sky — allowing roof surfaces to stay cooler than the surrounding air without using energy.
Typical commercial white paint reflects around 70% to 80% of incoming sunlight, said Distinguished Professor Baohua Jia, a nanotech expert at RMIT University in Melbourne, Australia, who is unaffiliated with Dewpoint Innovations.
Dewpoint’s coating demonstrated solar reflectance of up to 96% in a six-month outdoor trial reported in 2025.
That higher reflectivity means less heat was absorbed, keeping roof surfaces up to 6 degrees Celsius cooler than the surrounding air and