T.E.C.H. is one of the Gear Box rewards that you receive throughout the game. These T.E.C.H. are assigned to D-PAD for quick use which can be done at the Teletraan station or in the character creation screen in escalation.
The fastest way to get this achievement is to stand in front of a Teletraan station and activate over and over until the achievement pops.
This achievement can be earned in either Campaign or Escalation, and you'll probably get it through natural progression if you keep remembering to assign new T.E.C.H. whenever you're at the Teletraan station.