Researchers at Saarland University in the Netherlands, working with colleagues from Italy, have built what is being described by Robaid, as the most humanlike robot hand ever devised. According to the website for the project, called DEXMART, the scientists achieved a new level of dexterity for the Dexmart Hand, by employing strings to manipulate the fingers, much like that which is done with marionettes. It can be seen in action in a video posted by the team on YouTube.
Up to now, the model for robot hands, Robaid explains has been to use electric motors or pneumatics (using water or air pressure) to cause robot finger to move where researchers want them to. The problem with that is such hands are typically only useful in a single application. A strong claw-like hand, for example is really good at strong gripping and holding heavy objects, while those built with small electric motors are capable of very subtle movements. This new design, the team says, allows the robot hand to work in both environments, much as the human hand does. In addition to being able to mimic the way human hands work, the design also allowed for the hand to be built to the size of the average human hand, another stumbling block to prior efforts.
In the human hand, thin tendons, much like strings, are pulled to cause the fingers to curl in, when pressure is release, they uncurl. But tendons alone can’t allow a hand to grasp and hold a heavy object, that requires muscles. In the new robot hand, the researchers circumvented that problem by using string that is many times stronger than human tendons, allowing them to be used as ropes over pulleys when lifting heavy objects. The rest is a hand that is able to easily manipulate an egg that has had its inside removed and decorated for Easter, yet is strong enough to allow for picking up brick or heavy piece of machinery.
Robaid says the researchers used the human hand as their model from start to finish, attempting to replicate not only what it is capable of doing, but how it looks. The result is by far the most human looking and acting robot hand ever built. Watching it in action, people might be foregiven for forgetting it’s not connected to a live human being. The team says they’re not done yet, as they want to make movements of the hand and fingers even smoother, blurring the line between what human and robot hands can do.