This is far more complicated than it sounds. Engineers have to account for physical malfunctions, software bugs, sensor glitches and more. Even if the robot arms are functioning normally, human missteps can result in accidents--say you just happen to walk into one as its swinging around to hand a Pepsi to a co-work across the aisle. So researchers are also examining the special arm coverings and even allowing motors to decouple so that the force of the movement is not entirely transferred back to the heaviest part of the arm--which then might transfer it right back to your face. Another key area of study is proprioception, which could give the robots a human-like awareness of their surroundings and of when someone is particularly close to them.

If they successfully develop such an arm, it could lead to a full-blown, harmless robot and safer "physical human-robot interactions" (pHRI). I might handicap the plan a little better if the acronym hadn't led Pisa's Faculty of Engineering to call the whole project Phriends.