Solid-state salt and pressure cooling drops temperatures by several degrees Celsius almost instantly, reaching sub-zero levels in seconds

https://interestingengineering.com/innovation/chinas-cooling-touch-sub-zero-in-seconds

"when pressure applied, ammonium thiocyanate salt remains solid/ hydrated... when pressure released, salt rapidly dissolves into water absorbing massive heat almost instantly... 30°C (50 in high-heat environments) drop from ambient in seconds... relies on salt solution's physical state change, not hydrofluorocarbons... energy efficient... enables data centers to move away from energy-intensive fans and compressors toward this rapid chemical-physical cooling loop"

Related: Electronic cooling and energy harvesting using ferroelectric polymer composites
https://www.nature.com/articles/s41467-024-51147-6