What is Cryogenics?

by Cryonos Project on October 06, 2021

Cryogenics is the production and behaviour of materials at extremely low temperatures. The chemical properties of materials have been a key area of interest for researchers. The transition to liquid from gas has encouraged the development of new technologies and industries. Additionally, this has improved people’s understanding of new materials.


The temperature of a material is proportional to the measure of its energy. Cryogenic temperatures range from -150 degrees Celsius to -273 degrees Celsius, with -273 being the lowest attainable temperature. At this point, the actions of the molecules stop allowing them to be at the lowest state of energy.


A cryogenic environment typically materializes when gas begins to condense. Some of the common gases that liquefy cryogenics include oxygen, helium, nitrogen, and hydrogen. Liquid gases which are at or below -150 degrees Celsius usually help in the freezing of other materials.


The History Of Cryogenics

The name, Cryogenics, originates from the Greek word “Kyros” meaning cold. Cryogenics comprises a combination of Kyros or cold with the English word “to generate”, which forms the word cryogenics. Kelvin (K) is the measurement unit of very cold temperatures. The term Kelvin originates from the name, Baron Kelvin. According to Baron Kelvin, a new scale was necessary for very low temperatures that were impossible to measure using water’s material state change like Celsius or Fahrenheit. The theoretically coldest temperature is zero degrees, Kelvin.


In 1877, Louis Cailletet and Rasul Pictet used different methods to liquefy oxygen. This was the first time oxygen was liquefied. Progressively, another method was discovered and liquefying oxygen was possible to 90K. Later, nitrogen was able to be liquefied at 77K. This made scientists around the world compete in a bid to lower the temperature of materials to absolute zero. 


In 1898, hydrogen was liquefied at 20K by James DeWar. With every new invention and discovery comes difficulty. The prevailing challenge was how gases at such temperatures could be managed and stored effectively. The creation of the DeWar flasks made this possible, and has since then, continued to be applied.


The previous major improvement in the cryogenics industry was realized when Heike Kamerling Onnes was able to liquefy Helium at 4.2K and 3.2K. The discoveries after this development have been smaller because of the thermodynamic law. This law states that absolute zero cannot actually be reached, but, instead, be approached. The continued technological advancement after the previous major discovery allows us to freeze things extremely closer to absolute zero.

Uses Of Cryogenics

Cryogenics helps in the storage of large quantities of food. It is also applicable in MRI machines using liquid helium and requiring cryogenic cooling. Cryogenics helps in the freezing of blood and tissue samples, recycling, and the storage of large quantities of food. This product also helps cool superconductors.

Application Of Cryogenics


Cryogenics fluids can provide ultra-frozen temperatures, which allows electrons in various materials to move with little resistance. The ultra-frozen temperatures are ideal in spacecraft design and superconductors.


This type of surgery allows the use of cryogenic temperatures to eliminate unwanted tissue or tumors. This works effectively by freezing the targeted cells. Ice crystals form on the cells and eventually tear them apart.

Preserving food

Spraying food items with liquid nitrogen can help absorb the heat, consequently preserving the packaged foods. The liquid nitrogen applied on food items usually evaporates before consumption. As a result, this does not pose any chemical threat.


CryotherapCryotherapy is a state in which the human body undergoes treatment at extremely cold temperatures. This is beneficial as it reduces inflammation, manages pain, and increases energy. Cryotherapy research is still new, with its benefits not clearly understood and researched.

Using Liquids

Cryogen liquids should only be handled by persons who are aware of their properties and possible hazards. Carefully select the materials to use with cryogen liquids, as many common materials such as plastic, rubber, and steel become brittle at cryogenic temperatures.


When submersing materials in cryogen liquids, do so slowly to avoid any unwanted splashes. Always use tongs. Also do not wear any watches, jewelry, or such, as they may freeze if in contact with the liquids on exposed skin.

Transferring Liquids

When transferring to a new dewar flask, take care that the receiving container is already cool. Then fill slowly, so that the cryogen liquid may further cool the new flask. Always use the proper filling device and the correct containers for the specific cryogen liquid.

Personal Protection

 Always be sure to wear proper protection as per the procedure and be cautious that the liquids do not make skin contact. Wear a non-porous laboratory coat with long sleeves, as cryogen liquids pass through the porous material.

Always wear glasses, and a full-face shield or mask to protect your face also, take care not to breathe harmful gasses. The task may require that you use a respirator.


If contact does occur, immediately rinse the place with warm water.


Now you know the basic rules of safely handling cryogenic liquids.

Work with care.

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