World’s smallest refrigerator (at 25 X 15 micrometers)

Scientists have developed the world’s tiniest refrigerator – and it’s pretty cold too. Even smaller than a college dorm fridge, the microchip sized fridge can cool objects down to -459 degrees Fahrenheit.

The National Institute of Standards and Technology-designed refrigerators, each 25 by 15 micrometers, are sandwiches of a normal metal, an insulator and a superconducting metal. When a voltage is applied across the sandwich, the hottest electrons “tunnel” from the normal metal through the insulator to the superconductor. The temperature in the normal metal drops dramatically and drains extra heat energy from the objects being cooled.

I could use few of those now in Kolkata.

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