While only referred to in dialog as "the cube", the script for "Ship in a Bottle" used the term "tech cube".
The prop used to represent this device was designed by Makeup & Effects Laboratories. Prop fabrication supervisor Don Coleman later said of the prop, "It was machined up and silk-screened to get the pattern on the pieces before it was assembled. There was a light in the bottom so it would light up when you flipped a switch." (Star Trek: The Next Generation 365, p. 289)