Cambridge University scientists have developed a new electronic solid device for reducing CO2 emissions in cooling systems.
The device – which is based on layers of a material composed of oxygen and three metallic elements known as PST – offers to replace toxic and flammable greenhouse gases widely used in refrigerators and air conditioners.
According to the scientists, the electronic solid has so far displayed the largest electrocaloric effect observed in a body large enough for cooling applications.
It can thus be used in highly-efficient solid-state refrigerators and air conditioners, mitigating the need for bulky and expensive magnets.
Refrigeration and air conditioning systems currently consume a fifth of all energy produced worldwide, and as global temperatures continue to rise, demand is only going to keep going up.
Moreover, the gases used in these refrigerators and air conditioners are toxic, highly flammable greenhouse gases, and they only add to the problem of global warming when leaked into the air.
Researchers have been trying to improve cooling technology by replacing these gases with solid magnetic materials such as gadolinium.
Nevertheless, the performance of prototype devices has been limited to date, as the thermal changes are driven by limited magnetic fields from permanent magnets.
The Cambridge team has been hoping to remedy this ever since they identified an inexpensive, widely available solid earlier this year.
They believe the new solid could effectively compete with conventional coolants when put under pressure.
However, developing this material for cooling applications will involve a lot of new design work – which the Cambridge team is presently pursuing.
In the current work, the thermal changes are driven by voltage, explains study co-author Dr Xavier Moya.
“Using voltage instead of pressure to drive cooling is simpler from an engineering standpoint, and allows existing design principles to be repurposed without the need for magnets,” notes Moya.
The Cambridge team, working along with colleagues in Costa Rica and Japan, used high-quality layers of PST with metallic electrodes sandwiched in between.
This assured that the PST can withstand much larger voltages, and produce much better cooling over a much larger range of temperatures.
According to study co-author Professor Neil Mathur, replacing the heart of prototype magnetic fridges with a material that performs better, represents a major game-changer for those currently trying to improve cooling technology.
Image credits and content: Andy Shell-ShutterStock/University of Cambridge