In today's world of rapid technological development, many people may be unfamiliar with the concepts of "low temperature" and "superconductivity". Yet these insect-like liquids, such as liquid nitrogen and liquid helium, remain at the forefront of science and engineering, driving major changes in industry.
According to the definition of the International Society of Refrigeration, when the temperature is below 120 K (about −153°C), we call it "ultra-low temperature". Applications of this technology range from the creation of cooling materials to understanding their doping behavior at low temperatures, and are an important part of modern physics and engineering.
Liquid nitrogen is one of the most widely used ultra-low temperature liquids. Whether it is cryopreservation in the biomedical field or food cryopreservation, its footprints are everywhere. And through liquid helium, we can reach even lower temperatures, which is crucial for superconductivity and high-efficiency devices.
"The use of liquid nitrogen has become the standard in various industries because it is low-cost and easy to obtain."
The discovery of superconductors has brought unprecedented attention to ultra-low temperature technology. After being cooled by liquid nitrogen, these materials can exhibit zero resistance characteristics, so that the power transmission efficiency soars. Among them, the most representative example is the demand for liquid helium in some scientific instruments.
In the industrial world, ultra-low temperature processing technology is widely used in metal processing and improving the durability of materials. According to research, the wear resistance of metal parts treated with liquid nitrogen can be improved by 200% to 400%. This makes ultra-low temperature processing a hot topic in materials science, with excellent results achieved in industries such as automobiles and aerospace.
"The rise of the commercial cold treatment industry in 1966 marked the commercialization of ultra-low temperature technology."
In the biomedical field, the uses of liquid nitrogen and liquid helium are equally eye-catching, especially in the preservation of vaccines. For example, some COVID-19 vaccines need to be placed in an environment of −90°C to −60°C. This huge cold chain demand has prompted companies to urgently seek efficient cooling solutions.
“An effective cold chain is not only related to the safety of vaccines, but also affects the health of millions of people.”
With the continuous progress of space exploration, the use of liquid hydrogen and liquid oxygen has become a standard configuration for rocket launches. In NASA's space shuttle program, these cooling properties of hydrogen combined with liquid oxygen not only improve the efficiency of transportation, but also reduce the impact on the environment.
In addition to the above functions, there are many potential applications that are gradually emerging. For example, the new possibilities of refrigeration technology in food processing, transportation and safe storage will have a profound impact on solving the global food crisis.
From liquid nitrogen to liquid helium, these magical liquids are constantly changing the way we live and industrially produce. In the future, with the continuous advancement of science and technology, will more novel cooling technologies emerge to promote the convenient life we envision?