Super cooler
Researchers at the Hong Kong University of Science and Technology have unveiled a new eco-friendly cooling device that could benefit industries reliant on refrigeration. The team has developed an elastocaloric cooling technology that boasts a 48% boost in efficiency compared to traditional methods.
Space cooling and heating account for 20% of the world's total electricity consumption and are projected to become the second-largest source of global electricity demand by 2050.
Solid-state elastocaloric refrigeration using shape memory alloys is greenhouse gas-free, fully recyclable, and energy-efficient. It therefore offers an eco-friendly alternative to traditional methods, which often use refrigerants that can contribute to global warming.
However, until now, the small temperature lift of 20 to 50 kelvin achieved using this technology has hindered its commercialisation.
To overcome these challenges, the team led by Professors Sun Qingping and Yao Shuhuai used nickel-titanium shape memory alloys (NiTi SMAs) in a multi-material cascading configuration, achieving a record-breaking temperature lift of 75 kelvin. This surpasses the previous world record and marks a significant step towards the commercialisation of elastocaloric refrigeration. By selecting NiTi alloys with varying phase transition temperatures, the researchers have expanded the device's operational temperature range and enhanced its efficiency.
The team aims to further enhance shape memory alloys for sub-zero cooling and heat pumping, optimising materials for efficient refrigeration systems to boost commercialisation. The team's research, published in the journal Nature Energy, with Dr Guoan Zhou as the first author, opens the way for next-generation green cooling solutions that may help mitigate global warming.