To work safely alongside human workers, robot arms shouldn't be rigid. A new experimental robotic arm is modeled after the lithe trunks and tentacles of an octopus. The prototype of the device was developed by scientists from the EPFL Institute in Switzerland and the Delft University of Technology (TU Delft) in the Netherlands.
A series of electric actuators are arranged in a row along the core, connected end to end by flexible connectors. Surrounding the core is an open mesh structure in which the polymer elements are arranged in a helix (or "spiral").
By strategically trimming these elements at different parts of the structure, the degree to which they bend and deform in different directions can be adjusted. In this way, the team was able to make the outside of the arm soft enough not to injure someone it might hit, yet strong enough to protect the actuators and other internal electronics from impact.
The device is also much more flexible than traditional robotic arms that can only bend at the shoulder, elbow and wrist joints. Therefore, scientists believe that such arms would be ideal for fruit picking and other agricultural tasks, caring for the elderly, or assembly line work.
Project leader Professor Josie Hughes from EPFL said: "By inventing a new architectural structure - the pruning helix, we have designed a robotic arm that is excellent in terms of control, range of motion and safety. When the novel structure is combined with distributed execution (i.e. placing multiple actuators throughout the structure or device), this robotic arm has a large range of motion, high precision and is very safe during human-machine interaction."
The robotic arm technology is currently being commercialized through spin-off company Helix Robotics. A paper on the research was recently published in the journal NPJRobotics.