"A lie detector."
"The lie detector, Agent Coulson. This baby measures galvanic skin response, oxygen consumption, microexpressions, biofeedback, brainwaves, pupil dilation, voice biometrics. Ninety-six variables in all. Fury designed this himself. He wanted a lie detector Romanoff couldn't beat."
Phil Coulson and Eric Koenig[src]

The Lie Detector was a machine designed by S.H.I.E.L.D. Director Nick Fury to detect lies. A new updated version of the machine was introduced in the second incarnation of S.H.I.E.L.D. by the new director Jeffrey Mace.



Ward being subjected to the lie detector

The Lie Detector was designed by S.H.I.E.L.D. Director Nick Fury to measure galvanic skin response, oxygen consumption, pupil dilation, microexpressions, biofeedback, brainwaves, voice biometrics and other variables up to 96 as a way to determine if a subject is telling the truth about the questions he is asked. It is said that Nick Fury wanted a lie detector that Agent Romanoff could not beat, though he did not reveal if he was successful.

When Phil Coulson wanted to leave Providence with his team in order to pursue Fridge escapees, Agent Eric Koenig insisted that they use the Lie Detector first. During the tests, Grant Ward barely passed, on account of telling the half-truth that he was coming there for Skye, and the cable wire he implanted in his fingers to make the readings erratic.[1]

The Lie Detector was also used in Jeffrey Mace's S.H.I.E.L.D., with Agent Harlan controlling the machine. Jemma Simmons was often interrogated by Harlan. At her last test she received alarming results, however Mace told Harlan she would not be interrogated anymore.[2]