Mechanical arm
Other robotic arms were invented in 1961 by Unimate, evolving to the PUMA arm. In 1963, the Rancho arm was designed, along with many others in the future. Even though Joseph Engelberger marketed Unimate, George Devol invented the robotic arm. It focused on using Unimate for tasks that are harmful to humans. In 1959, a 2700 pound Unimate prototype was installed at the General Motors die-casting plant in Trenton, New Jersey. The Unimate 1900 series became the very first produced robotic arm for die-casting. During a very short period of time, it had produced at least 450 robotic arms were being used. It still remains one of the most significant contributions in the last one hundred years. As years went by, technology seemed to evolve, helping to build better robotic arms. Not only companies invented different robotic arms, but so did colleges. In 1969, Victor Scheinman from Stanford University invented the Stanford arm, where it had electronically powered arms that could move through six axes. Marvin Minsky, from MIT, built a robotic arm for the office of Naval Research, possibly for underwater explorations. This arm had twelve single degree freedom joints in this electric- hydraulic- high dexterity arm. Robots were initially created to perform a series of tasks that humans found boring, harmful, and tedious.
Robot
Possibly the most prolific author of the twentieth century was Isaac Asimov (1920–1992) who published over five-hundred books. Asimov is probably best remembered for his science-fiction stories and especially those about robots, where he placed robots and their interaction with society at the center of many of his works. Asimov carefully considered the problem of the ideal set of instructions robots might be given in order to lower the risk to humans, and arrived at his Three Laws of Robotics: a robot may not injure a human being or, through inaction, allow a human being to come to harm; a robot must obey orders given it by human beings, except where such orders would conflict with the First Law; and a robot must protect its own existence as long as such protection does not conflict with the First or Second Law. These were introduced in his 1942 short story "Runaround", although foreshadowed in a few earlier stories. Later, Asimov added the Zeroth Law: "A robot may not harm humanity, or, by inaction, allow humanity to come to harm"; the rest of the laws are modified sequentially to acknowledge this.