Researchers from the University of Chicago’s Pritzker School of Molecular Engineering have published details of a new material that can auto-regulate its environment by changing its infrared colors and liquid-solid state. In the future, the ultra-thin material film could be added to a building’s thermal facade in order to reduce the need for HVAC systems.

“Nearly 30% of the energy consumption and 10% of the greenhouse gas come from buildings,” says Chenxi Sui, a member of the research team whose findings have recently been published in the journal Nature. “Looking for diverse approaches to maintain a comfortable building temperature becomes a key point to creating a sustainable and carbon-negative future. Instead of controlling the indoor temperature in conventional ways, we keep wondering: Can we treat the building like the human body?”

The behavioral pattern of the new material has been likened to that of a chameleon that changes the color of its skin to regulate its temperature. Similarly, the 0.5mm-thick film made from the new material controls its thermal properties by changing its infrared color. In a solid copper state, the material can retain its heat to become an insulating blanket for the internal environment, before converting to a liquid solution to absorb internal heat to be emitted outwards, thus cooling the internal environment.

The change in state between liquid and solid is triggered by an electrical current, a process known as electrochromism. In one plausible future use of the material, an electrical current could be automatically triggered when a room’s temperature becomes uncomfortably hot or cold, causing the film to change state and bring the temperature back into regulation.

“Our flexible electrochromic thermal emissivity tuning system is compatible with a wide range of buildings (historic and new construction) and offers a non-destructive way to enhance the sustainability of the buildings,” Sui continues. However, in addition to the relatively short lifespan of the material (currently three years if used twice daily), Sui notes that the materials associated with the process remain expensive and complicated to fabricate, impeding its scalability.

News of the research comes weeks after scientists from MIT and Harvard uncovered the key ingredient behind ancient Rome’s ‘self-healing’ concrete. In late 2022, meanwhile, MIT researchers developed a new method of 3D printing wood, while Penn State announced the launch of a study into how fungal biomaterials can help reduce construction waste.