A team of researchers from the Hong Kong University of Science and Technology (HKUST) has developed a durable elastocaloric cooling system that uses a fatigue-resistant shape-memory alloy (SMA) to maintain stable cooling performance for one million operating cycles.

The solid-state refrigeration device addresses a key durability challenge in conventional cooling technologies, potentially offering a more reliable and environmentally friendly approach to refrigeration.

Source: Hong Kong University of Science and Technology

Elastocaloric cooling uses SMAs that heat and cool when mechanically stressed and released, thus offering a potential alternative to conventional refrigeration. However, existing systems often use nickel-titanium (NiTi) alloys that experience fatigue, causing cooling performance to decline over time.

As such, the team developed a zero-degradation elastocaloric cooling device using a new titanium-nickel-copper-cobalt (TiNiCuCo) SMA and a durable double-layer fin structure. The design improves heat transfer, resists mechanical fatigue and reduces the number of components by 50%.

Further, the prototype delivered 400 W of cooling power and a 41° C temperature span for one million cycles without performance loss. The refrigerant also showed no degradation after 100 million accelerated cycles and is expected to operate for more than a decade under real-world conditions, according to the team.

The researchers are now developing an air conditioner based on the technology, with the goal of improving efficiency and power density, and reducing cost.

An article detailing the material, “A zero-degradation elastocaloric cooling device using fatigue-resistant refrigerant,” appears in the journal Joule.