In "Terminator 2: Judgment Day", what substance is the T-1000 made of?

In "Terminator 2: Judgment Day," the T-1000 is made of mimetic polyalloy, a fictional liquid-metal material that lets it reshape itself and imitate people or objects. "Liquid metal" describes its appearance, but mimetic polyalloy is the specific in-universe name.

The T-1000 is a more advanced design than the T-800. Instead of having a conventional metal endoskeleton covered by living tissue, it is portrayed as an entirely liquid-metal machine. It can flow through narrow spaces, repair damage, alter its face and clothing-like surface, and form blades from its arms.

Its mimicry has limits. The T-1000 cannot create complex mechanical devices with working parts, and its total mass restricts the size of forms it can copy. The film also shows that extreme cold can temporarily freeze and shatter it, while the heat of molten steel ultimately destroys it.

Robert Patrick played the T-1000, whose visual effects became one of the landmark achievements of early computer-generated cinema. Industrial Light & Magic combined CGI with practical effects and animatronics to create the character’s liquid transformations in the 1991 film.