Stretchable material heat conduction has taken a major leap forward as engineers at MIT have developed a polymer that can rapidly and reversibly switch how it conducts heat simply by being stretched. The discovery opens new possibilities for adaptive cooling technologies in clothing, electronics, and building infrastructure.
Engineers at the Massachusetts Institute of Technology have developed a new polymer material that can rapidly and reversibly switch how it conducts heat—simply by being stretched.
The research shows that a commonly used soft polymer, known as an olefin block copolymer (OBC), can more than double its thermal conductivity when stretched, shifting from heat-handling behaviour similar to plastic to levels closer to marble. When the material relaxes back to its original form, its heat-conducting ability drops again, returning to its plastic-like state.
The transition happens extremely fast—within just 0.22 seconds—making it the fastest thermal switching ever observed in a material, according to the researchers.
The findings open up possibilities for adaptive materials that respond to temperature changes in real time, with potential applications ranging from cooling fabrics and wearable technology to electronics, buildings, and infrastructure.
The research team initially began studying the material while searching for more sustainable alternatives to spandex, a petroleum-based elastic fabric that is difficult to recycle. During mechanical testing, the researchers noticed unexpected changes in how the polymer handled heat as it was stretched and released.
A new direction for adaptive materials
“We need materials that are inexpensive, widely available, and able to adapt quickly to changing environmental temperatures,” said Svetlana Boriskina, principal research scientist in MIT’s Department of Mechanical Engineering, in a media statement. She explained that the discovery of rapid thermal switching in this polymer creates new opportunities to design materials that actively manage heat rather than passively resisting it.
The research team initially began studying the material while searching for more sustainable alternatives to spandex, a petroleum-based elastic fabric that is difficult to recycle. During mechanical testing, the researchers noticed unexpected changes in how the polymer handled heat as it was stretched and released.
“What caught our attention was that the material’s thermal conductivity increased when stretched and decreased again when relaxed, even after thousands of cycles,” said Duo Xu, a co-author of the study, in a media statement. He added that the effect was fully reversible and occurred while the material remained largely amorphous, which contradicted existing assumptions in polymer science.
The discovery demonstrates how stretchable material heat conduction can be actively controlled in real time, allowing materials to respond dynamically to temperature changes.
How stretching unlocks heat flow
At the microscopic level, most polymers consist of tangled chains of carbon atoms that block heat flow. The MIT team found that stretching the olefin block copolymer temporarily straightens these tangled chains and aligns small crystalline regions, creating clearer pathways for heat to travel through the material.
“This gives the material the ability to toggle its heat conduction thousands of times without degrading
Unlike earlier work on polyethylene—where similar alignment permanently increased thermal conductivity—the new material does not crystallise under strain. Instead, its internal structure switches back and forth between straightened and tangled states, allowing repeated and reversible thermal switching.
“This gives the material the ability to toggle its heat conduction thousands of times without degrading,” Xu said.
From smart clothing to cooler electronics
The researchers say the material could be engineered into fibres for clothing that normally retain heat but instantly dissipate excess warmth when stretched. Similar concepts could be applied to electronics, laptops, and buildings, where materials could respond dynamically to overheating without external cooling systems.
“The difference in heat dissipation is similar to the tactile difference between touching plastic and touching marble,” Boriskina said in a media statement, highlighting how noticeable the effect can be.
The team is now working on optimising the polymer’s internal structure and exploring related materials that could produce even larger thermal shifts.
“If we can further enhance this effect, the industrial and societal impact could be substantial,” Boriskina said.
Researchers say advances in stretchable material heat conduction could significantly influence future designs of smart textiles, electronics cooling, and energy-efficient buildings.
The study has been published in the journal Advanced Materials. The authors include researchers from MIT and the Southern University of Science and Technology in China.
Researchers say advances in stretchable material heat conduction could significantly influence future designs of smart textiles, electronics cooling, and energy-efficient buildings.