Researchers at the Hong Kong University of Science and Technology (HKUST) have developed a groundbreaking eco-friendly cooling device that could transform industries relying on refrigeration.
This new technology, known as elastocaloric cooling, boasts record-breaking efficiency, making it a promising alternative to traditional cooling methods and a potential game-changer in the fight against climate change.
Traditional refrigeration systems use vapor compression technology, which relies on refrigerants that contribute significantly to global warming.
In contrast, the new elastocaloric cooling technology developed by the HKUST team uses solid-state materials called shape memory alloys (SMAs) that are free from harmful greenhouse gases. These materials are not only energy-efficient but also 100% recyclable, making them a much greener option.
One of the main challenges with elastocaloric cooling has been its relatively low temperature lift—the device’s ability to move heat from a cold area to a warm one.
Until now, this technology could only achieve a temperature lift of 20 to 50 K (Kelvin), limiting its effectiveness and hindering its commercial use.
To overcome this, the HKUST research team, led by Professors Sun Qingping and Yao Shuhuai from the Department of Mechanical and Aerospace Engineering, developed a new approach.
They created a multi-material cascading elastocaloric cooling device using different types of nickel-titanium (NiTi) shape memory alloys.
Each of these alloys has a unique phase transition temperature, which the team matched to different parts of the cooling device—one for the cold end, one for the intermediate end, and one for the hot end.
By aligning the working temperatures of each part of the device with the appropriate phase transition temperatures, the researchers expanded the overall temperature range that the device could handle.
This allowed the device to operate much more efficiently, achieving a temperature lift of 75 K—shattering the previous world record of 50.6 K.
Their research, titled “A Multi-Material Cascade Elastocaloric Cooling Device for Large Temperature Lift,” was published in the prestigious journal Nature Energy. This breakthrough could have significant implications for the future of cooling technology.
Looking ahead, the team plans to continue refining their elastocaloric cooling technology. They aim to develop even more efficient shape memory alloys and improve the system’s performance for both sub-zero cooling and high-temperature heating applications. These advancements could make elastocaloric cooling a viable alternative for a wide range of uses, from home refrigeration to industrial cooling.
Cooling and heating account for about 20% of global electricity consumption, and this number is expected to grow significantly by 2050. As such, the development of energy-efficient and eco-friendly cooling solutions is crucial.
Prof. Sun is optimistic about the future, stating, “With continued advancements in materials science and engineering, we believe elastocaloric refrigeration can become the next generation of green, energy-efficient cooling and heating solutions, helping to reduce global carbon emissions and combat climate change.”
