Researchers from the Universite de Sherbrooke have designed a robotic limb that can smash through walls while still being safe for human-robot interactions. Other wearable exoskeleton-like arms help with moving objects, stabilization, and other lightweight tasks, but none that have enough power to physically destroy objects but still be delicate enough to pick fruit and vegetables. The waist-mounted supernumerary robotic arm weighs around eight to nine pounds and is tethered to a hydraulic system via several hoses.
The team developed the 3DOF robotic arm using magnetorheological (MR) clutches and hydrostatic transmission lines. At the same time, the tethered configuration allows the power unit to sit on the ground, minimizing the weight for the user. Those MR clutches also minimize the actuation inertia, which provides fast dynamics and good back-drivability, enabling the wearer to remain upright while smashing walls.
According to its creators, the robotic arm has an experimental open-loop force-bandwidth of 18Hz at each joint, and the maximum reached by the end-effector is 3.4 meters per second, which helps offset human motions.
While there are a myriad of applications that could benefit from having an additional limb, the robotic arm still has a long way to go as it lacks mobility and autonomy. As it stands right now, the arm is controlled by another person via a smaller handheld model. That said, it can still be equipped with a robotic gripper and is agile enough to handle delicate objects, and quick enough to play badminton. There’s even a level of safety built-in to the arm to prevent injury while using it, as the arm is mechanically limited in its movements, and the joints are designed to reduce its force when it hits an object. It will be interesting to see how the researchers will evolve the arms design in the near future.