This is the device responsible for shifting a TARDIS into and out of the Vortex. The Molecular Dematerialization Codes are needed to activate the laser trigger found inside the circuit. The Symbiotic Relationship Circuits automatically input these codes if the operator is a Time Lord. Minor errors in the code will probably result in poor accuracy in navigation. It might be possible to bypass the codes and activate the laser trigger using a Light Accelerator. Once the circuit is activated Dematerialization begins.

Components of the circuit include a laser trigger, directional memory wafers, and stabilizing dio-nodes connected to transceiving telo-circuits. The Dematerialization casing is attached to artron filaments using a steady-state micro-welding technique, first pioneered by the Lamadines. On the Mark I Console, the dematerialization Circuit is located beneath the Main Door Control.

With the right technical knowledge it is possible to convert a Demat Circuit into a temporal bomb that would spread a TARDIS across 1000 years of time - destroying any solar system that happens to occupy that time zone. A circuit fitted with a Dematerialization Cut-Out or a Return Circuit might be more susceptible to this sabotage. It should be noted that a dematerialization circuit designed for a Mark II console won't work with a Mark I console and vice versa. It would be necessary to upgrade the entire TARDIS console to make a newer circuit compatible.