Astronauts repaired the arm's current hand - which was growing arthritic after 17 years of use - during a series of spacewalks in recent months.
All six crew members at the orbiting outpost can speak to CIMON, though it has been taught to work best with Gerst.
The spacecraft carries over 5,900 pounds of load, including experimentation and investigation equipment such as the Crew Interactive Mobile Companion, Micro-12 and Ecosystem Spaceborne Thermal Radiometer Experiment on Space Station.
The large, round, plastic robot head is part of SpaceX's latest supply delivery to the International Space Station.
CIMON will serve as Gerst's right-hand man during his Horizons mission, where the ESA astronaut will carry out an array of science experiments, like measuring muscle retention during spaceflight, testing astronauts' perception of time, and designing plasma devices that disinfect wounds.
The Falcon 9 rocket lifted off at its scheduled time of 5:42 a.m. Friday.
Researchers hope that with its face, voice and artificial intelligence, it will become a genuine "colleague" on board, helping astronauts with their daily routines, and warning of any impending problems - much like the HAL robot in Stanley Kubrick's 2001 was created to do.
The German Aerospace Center plans for CIMON to undergo three one-hour sessions to demonstrate how well the robot can help with experiments, like a crystal growth study, a test for its eight on-board cameras and an exercise to help Mr. Gerst solve a Rubiks cube.
Once back on, voice recordings are activated again.
The rocket, operated by Elon Musk's SpaceX corporation, was contracted to haul almost 6,000 pounds of cargo for NASA to the International Space Station.
Researchers say CIMON is not yet trained to respond to all possible emergencies and protocols on the space station. The dragon first went to the space station in July 2016, while the Falcon 9 was flying in April this year when it launched a new planet-hunting satellite for NASA called Tess.