From UPSC perspective, the following things are important :
Prelims level : Elastocaloric effect
Mains level : Elastocaloric effect and its applications
- When rubbers bands are twisted and untwisted, it produces a cooling effect.
- This is called the “elastocaloric” effect, and researchers have suggested that it can be used in a very relevant context today.
- Researchers have found that the elastocaloric effect, if harnessed, may be able to do away with the need of fluid refrigerants used in fridges and air-conditioners.
- These fluids are susceptible to leakages, and can contribute to global warming.
How it works?
- In the elastocaloric effect, the transfer of heat works much the same way as when fluid refrigerants are compressed and expanded.
- When a rubber band is stretched, it absorbs heat from its environment, and when it is released, it gradually cools down.
- In order to figure out how the twisting mechanism might be able to enable a fridge, the researchers compared the cooling power of rubber fibres, nylon and polyethylene fishing lines and nickel-titanium wires.
- They observed high cooling from twist changes in twisted, coiled and supercoiled fibres.
- The level of efficiency of the heat exchange in rubber bands “is comparable to that of standard refrigerants and twice as high as stretching the same materials without twisting”.
- To demonstrate this setup, the researchers developed a fridge the size of a ballpoint pen cartridge that was able to bring down the temperature of a small volume of water by 8°C in a few seconds.
- They suggested that their findings may lead to the development of greener, higher-efficiency and low-cost cooling technology.