Robobrains were created before the Great War by General Atomics International both for the U.S. military and for the civilian sector. Official government records list only chimpanzee brains as being used in the robots, but at least some human brains were taken from the bodies of executed criminals. Many of these criminals were insane, so the resulting robobrains also tended to be unstable, despite complete reprogramming via the CODE technology. Some of these human-robobrains hybrids would try to kill themselves, apparently resenting being made into cyborgs.
A robobrain moves on a tracked chassis (using dual 40 hydro-processor motors), either on a fixed or flexible mount. This is attached to a sizable cylindrical torso with a reinforced glass dome on top, housing the central processing unit with the organic brain suspended inside. In addition, to use consoles, operate levers, or engage targets with weapons, they have two flexible manipulators, ending in three point claws, on the sides of their torsos.
Robobrains were going to be the next generation of robotic soldier in the war against China, but their production costs made it difficult to implement their introduction into the American military.
The robobrain's organic brain is suspended in pressurized bio med gel (which is the primary reason the brains can continue to function for several centuries). Any damage to the casing or the brain itself can disrupt the robot's brainwaves and damage its neural connection to the rest of the body, affecting the robot's performance. Feeding the organic brain information about its surroundings are special sensors (typically with software written in 2076 installed), called Sensors '76. Apart from providing a real-time high resolution feed of the robot's surroundings, they are also capable of switching to infrared mode, in case the main sensors, for one reason or another, become useless for operating in unlighted areas.
The manipulators in some robobrain models are designed to operate regular human weaponry (such as AK-112 assault rifles), while some others have integrated laser guns (wattage equivalent to AEP7 laser pistols), supported by integrated mesmetrons. In addition, all robobrains have a built-in voice synthesizer.
Unlike in previous Fallout games, the robobrain from Fallout 4 appears to have a built-in eye in front of the brain.
There is a slight inconsistency regarding robobrains in the Far Harbor and Automatron add-ons; the ones found on the Island are considerably shorter than their "cousins" encountered in the Commonwealth. This is especially evident if the Survivor enters Vault 118 with a robobrain companion made from the robot workbench. However, a likely explanation is that the robobrains of Vault 118 are custom models built specifically for the vault dwellers, and would thus differ from the mass-produced models seen elsewhere.