A video demonstration of a university project involving a researcher wearing a C-shaped gripping claw attached to his right hand while a nearby robotic arm mimicked his exact movements showed the promise of hydraulic technology designed to be low friction.

The researcher in the video lowered and raised his arm, swept it left and right, and bent it at the wrist, smooth actions that were copied in tandem by the robotic arm. What was not readily apparent was how the human operator was able to feel the same forces as the mechanical arm when it closed on an object, allowing the user to get a sense of textured surfaces.

The Northeastern project involves building remote-controlled robot arms that do not have heavy motors traditionally installed in the wrist joints. Instead, they are placed in the base of the machine.

"With no motors in the arm, they are much lighter than a traditional arm," says Peter Whitney, assistant professor of mechanical and industrial engineering at Northeastern. "So now if you have a lighter arm, it's much easier to move it around."