Perillos of Athens
Of all the inventors on this list, this guy may be the one who most deserved to die at the hand of his own invention. Perillos was a bronze worker who designed a device called the Brazen Bull to be used to painfully execute criminals. The Brazen Bull was a hollow bull. Prisoners were locked inside and roasted to death by a fire underneath. The device was even designed to channel the screams of the burning prisoner out of its nose to sound like a bull. Perillos pitched his invention to Phalaris, a tyrant lord of Acragas in Sicily. After Perillos showed Phalaris the bull, the inventor was put inside and a fire was lit underneath him. History isn't clear about if Perillos was pulled out before dying, only to be thrown off a cliff by Phalaris' men, or if he expired within the bull. Either way, the bull did him in.