Getting a grip on robotic grasp



“This is a completely intuitive and natural way to move your robotic fingers,” says Harry Asada, the Ford Professor of Engineering in MIT’s Department of Mechanical Engineering. “You do not need to command the robot, but simply move your fingers naturally. Then the robotic fingers react and assist your fingers.”


Biomechanical synergy

The robot, which the researchers have dubbed “supernumerary robotic fingers,” consists of actuators linked together to exert forces as strong as those of human fingers during a grasping motion.




The researchers used this information to develop a control algorithm to correlate the postures of the two robotic fingers with those of the five human fingers. Asada explains that the algorithm essentially “teaches” the robot to assume a certain posture that the human expects the robot to take.

Bringing robots closer to humans

For now, the robot mimics the grasping of a hand, closing in and spreading apart in response to a human’s fingers. But Wu would like to take the robot one step further, controlling not just position, but also force.

“Right now we’re looking at posture, but it’s not the whole story,” Wu says. “There are other things that make a good, stable grasp. With an object that looks small but is heavy, or is slippery, the posture would be the same, but the force would be different, so how would it adapt to that? That’s the next thing we’ll look at.”


“After you’ve been using it for a while, it gets used to your pronunciation so it can tune to your particular accent,” Wu says. “Long-term, our technology can be similar, where the robot can adjust and adapt to you.”


“This is breaking new ground on the question of how humans and robots interact,” says Matthew Mason, director of the Robotics Institute at Carnegie Mellon University, who was not involved in the research. “It is a novel vision, and adds to the many ways that robotics can change our perceptions of ourselves."


“This is a prototype, but we can shrink it down to one-third its size, and make it foldable,” Asada says. “We could make this into a watch or a bracelet where the fingers pop up, and when the job is done, they come back into the watch. Wearable robots are a way to bring the robot closer to our daily life.”