Biochip

Biochips are a part of all augmentations distributed in the world at the time of Deus Ex: Human Revolution. These chips control all augments in a person's body, from ocular implants to full-body augments.

Deus Ex: Human Revolution
In the game, Adam Jensen, and presumably anyone who has an augment has a biochip. The biochip seems to control all non-essential augments in the body, such as upgrades and systems like the Typhoon Explosive System.

Later in the game, biochips around the world suffer a glitch that causes pain in the augmented person. The World Health Organisation then broadcasts a message stating that the biochips are faulty and should be replaced at a LIMB Clinic. The player can then choose to have the biochip replaced, or leave it in and risk further "glitches".

Near the end game, inside Omega Ranch, Zhao Yun Ru reveals the proper purpose of the new biochips- they disable all the augments in a person's body at the push of a killswitch. She triggers this switch, and augments are disabled throughout the world- including Adam Jensen's, if you opted to have it replaced earlier in the game. However, Adam's augs controlling movement of his limbs are not disabled, allowing him to fight Jaron Namir, albeit at a huge disadvantage.