A device fixed to the skull of every inmate of an Akritirian prison, which irritates the nervous system until the prisoners become violent and paranoid and eventually kill one another.
The clamp is an implant attached to the back of the head of each prisoner held in the Akritirian maximum security detention facility. It appears in the Voyager episode The Chute.
The prisoners believe it is a tracking or restraint device. In fact it stimulates the production of a neurotransmitter that drives aggression, so that the inmates grow steadily more irritable and murderous. The authorities supply little food and simply let the population destroy itself. One inmate, Zio, has written a manifesto arguing that the clamp is an experiment.
Harry Kim and Tom Paris are thrown into the prison after being wrongly convicted of a bombing. As Paris lies wounded, the clamp pushes Kim close to killing his friend. Kim also discovers that the chute leads not to the surface but into space; the prison is a station in orbit.