Researchers at Harvard University have unveiled a novel robotics innovation that mimics the rolling motion of human joints, potentially paving the way for robots that move more fluidly, safely, and efficiently than current designs allow. Unlike traditional rigid or pivoting joints, this “rolling joint” mechanism promises enhanced maneuverability in applications ranging from prosthetics to agile mobile robots.
Traditional robotic joints typically operate like hinges or sliders, using motors and gears that restrict movement to predefined axes. While effective for many industrial tasks, the fixed-axis approach limits adaptability and natural motion, especially in environments designed for human activity. The new mechanism, inspired by biomechanics, allows a continuous rolling contact between surfaces, enabling smoother angle transitions and improved torque distribution.
“Whenever you have some robot, and you have an idea of what it needs to do – maybe it’s a walking robot – you can start to think about the best places to output force,” said Colter Decker, a Ph.D. student at SEAS and first author of the study.
The rolling joint concept replaces rigid pivot points with surfaces that roll against each other, similar to how a wheel rolls across the ground rather than sliding. This design reduces friction, distributes stress more evenly, and allows for greater flexibility in movement without the need for complex control systems.
In prototype tests, robots equipped with rolling joints were able to perform tasks that require high dexterity, such as climbing uneven terrain, adjusting posture autonomously, and stabilizing themselves in response to disturbances. It is also a prime breakthrough product due to less energy consumption than traditional actuators.
“We aim to offload as much motion control as possible to the mechanics and materials of the robot, so that the control system can focus on task-level goals. Colter’s methods do exactly that, and in a very elegant way, both mathematically and mechanically,” said Robert J. Wood, senior author of the paper.
The team says that the concept originated from attempts to enhance soft robotic grippers, which need to gently wrap around objects while still exerting a strong grip. The team explored the idea of using rigid links paired with flexible joints, studying rolling contact joints to replicate the function of bones and cartilage in human limbs.
Experts say this approach marks a shift from treating robots as stiff machines toward creating systems that better integrate into environments built for humans. In fields like elder care, physical therapy, and collaborative automation, the ability to move with finesse can mean the difference between practical assistance and awkward interaction.
While still in the research phase, Harvard’s rolling joint design points to a future where robots are not just stronger or faster, but physically more adaptable and safe around people.
You can read the complete research paper here.