October 9, 2014 – Roboticists have long been trying to build robot arms that are light, nimble, and safe to operate near people. Some designs rely on compliant actuators, artificial muscles, or sensors and software to keep the arms from smashing into things that they’re not supposed to. The challenge, however, is that most robot arms are stuffed full of electric motors and gears, and these are relatively big and heavy, adding to the size and weight of the arms.