Definition - What does Cryogenics mean?
Cryogenics is the name given to the study of materials at extremely low temperatures. This includes both the production of these materials and the way they behave. Cryogenics are not to be confused with refrigeration, as cryogenics deal with temperatures lower than those in refrigeration. The point at which we cross over from refrigeration to cryogenics is not well defined, but it is, generally, accepted to be a point between -150°C and -180°C.
Safeopedia explains Cryogenics
Cryogenics has inputs from the three major disciplines: physics, chemical engineering and mechanical engineering. The extremely low temperatures involved in cryogenics make way for unusual applications in different fields due to the changes in physical properties of a material when at extremely low temperatures. There are several branches of studies from cryogenics including cryosurgery, cryobiology, cryoelectronics, cryonics, cryotronics, etc..