Liquid nitrogen: uses and applications (2025)

Liquid nitrogen has a significant role in the medical field. The cold liquid is regularly used for the following (operations):

• Cryopreservation: One of the most common medical procedures performed with liquid nitrogen is the cryopreservation of biological samples such as semen, egg cells, and embryos. The method allows these biological materials to be safely stored for an extended period of time.
• Cryosurgery: In dermatology and other medical specialities, liquid nitrogen is used for cryosurgery, a technique that freezes abnormal or unhealthy tissue for removal. The use of liquid nitrogen reduces the risk of infection and scarring.
• Cryosauna: Outside of surgical applications, liquid nitrogen is also used in cryosaunas with the purpose of repairing muscles and boosting the immune system. These treatments are popular for sports injuries.

There is virtually no industry in which refrigeration is as essential as in the food industry. It is, therefore, no surprise that liquid nitrogen is used here in many ways:

• Rapid freezing: Liquid nitrogen is often used to freeze food rapidly, for example, in cooling trays, cold rooms, or cryogenic freezing tunnels. The advantage? With fast freezing, the cellular structure of the food remains optimally preserved. This results in better quality and texture when the food is defrosted. Food producers also use the extreme cold of liquid nitrogen to instantly cool pre-cooked products to stop the cooking process from continuing.
• Packaging: Gaseous nitrogen is used to package products under a protective atmosphere. Liquid nitrogen is vaporized into a gas cloud, in which products can be hygienically packed.
• Special effects: In restaurants and bars, liquid nitrogen is used to make ice cream or provide dishes and drinks with a smoky effect. In this way, the cryogenic liquid contributes to the special effects of various culinary drinks and dishes.

A third sector in which liquid nitrogen is used is scientific research. Cooling is also important in science, to which end liquid nitrogen is used for the following purposes:

• Equipment cooling: Many experimental techniques require the cooling of samples or equipment to cryogenic temperatures to reduce thermal noise and increase resolution. This cooling is accomplished with cryogenic fluids such as liquid nitrogen, liquid argon, or liquid helium.
• Low-temperature research: Liquid nitrogen is also used in research into the unique properties of materials at extremely low temperatures. Examples include research into superconductivity and particle accelerators. In this field, liquid nitrogen is often used as a thermal shield, ensuring that liquid helium is less likely to evaporate and superconductivity is easier to maintain.

Finally, we find liquid nitrogen used in the production of various materials and products. To name a few well-known examples:

• Shrink fits: In the automotive industry, liquid nitrogen is used to temporarily shrink metal components, such as gears, axles, and engine parts, to fit them into another part. This so-called shrink fit ensures fewer expensive parts are needed to assemble a product. This makes the manufacturing process economic and more sustainable.
• Extrusion of aluminum profiles: Due to the internal cooling of the extruding mold, less material amalgamates with the mold during extrusion. This ensures a smoother surface of the finished product.
• Electronics: Liquid nitrogen is widely used to test electronic chips. By rapidly cooling sensitive electronic components to -40°C, their ability to withstand cold in everyday use is examined. In addition, liquid nitrogen is used as a cryopump in cooling shields to create an ultra-pure vacuum space in which chips can be produced by molecular layer building via MBE (Multi-Beam Epitaxi) systems.
• Infrastructure maintenance: Liquid nitrogen is used to temporarily freeze pipeline sections for repair. Freezing the pipeline prevents leakage during repairs or maintenance.
• Cold traps for maintaining vacuum: Cold traps protect vacuum pumps from moisture and condensable solvent vapors produced upstream in high vacuum systems.