Novel Solid-State Alternative to Commerical CoolingKrishna Amin (St Catharine’s). October 16, 2019.
Material science researchers at the University of Cambridge have recently reported in Nature the development of a new design of electrocaloric (EC) cooling devices (which can change in temperature when an electric field is applied) which works over a wider and more usable temperature range and a larger effect than previous proposals.
The new designs make use of multi-layer capacitors (MLCs) made of an assembly of films of the well-known EC material PST. Their highly-ordered PST was able to ‘access large EC effects’ while representing a potential macroscopic option. Recorded temperature changes peaked at 5.5°C near room temperature, and showed changes of 3°C over temperatures ranging from 21°C – 197°C. Compared to current macroscopic cooling devices – ones that make use of magnetocaloric (MC, which change in temperature when a magnetic field is applied) cooling using bulky, permanent magnets and gadolinium (Gd – a lanthanide metal) – these data fare well, suggesting that EC cooling using MLCs of highly ordered PST could provide a cost-effective alternative to current MC designs.
This has exciting implications for cooling consumer electronics and solar cells and can be used to reduce below room temperature using doped PST. Furthermore, the new design could lead to alternatives to current methods of air conditioning, which are relatively energy-intensive.
Nair, B., Usui, T., Crossley, S. et al. Large electrocaloric effects in oxide multilayer capacitors over a wide temperature range. Nature 575, 468–472 (2019).