This Two-Armed Robot Throws a Baseball at 67 MPH
Robot arms as light as yours could soon work safely beside you.
Engineers built a two-armed robot called AthenaZero designed to minimize inertia without compromising control authority. Using quasi-direct drive actuation and transmission remotization, it achieves an effective endpoint mass comparable to that of a human — about an order of magnitude less than conventional robot manipulators — and its inherent torque transparency makes it well-suited for dynamic manipulation. The robot threw at speeds in excess of 30 m/s (about 67 mph), and caught and batted at speeds in excess of 14 m/s (about 31 mph) over a short 7.3 m distance. Batting practice and a game of catch were then performed in both robot-to-robot and human-to-robot variations. The work is described as the cover article to the September 2026 issue of Science Robotics.
- AthenaZero has two arms whose hands weigh about as much as a human's — roughly 10 times lighter than normal robot arms of similar strength.
- It threw balls faster than 67 mph and caught and batted balls at over 31 mph across a 24-foot gap, including playing catch with a person.
- Light, fast arms are the key to robots that can safely work next to people instead of behind safety cages.
Why It Matters
Faster, lighter robot arms could mean safer robots working beside people and quicker, cheaper package handling.