Elastocaloric effect

Mains Paper 3 : Awareness In The Fields Of It, Space, Computers, Robotics, Nano-Technology, Bio-Technology |

From UPSC perspective, the following things are important :

Prelims level : Elastocaloric effect

Mains level : Elastocaloric effect and its applications

Elastocaloric effect

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.

Efficiency

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.

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