If The Addams Family was a science fiction show, “Thing” might look something like this.
Researchers have developed a robotic hand that can not only skitter about on its fingertips, it can also bend its fingers backward, connect and disconnect from a robotic arm and pick up and carry one or more objects at a time, researchers report January 20 in nature Communications. With its unusual agility, it could navigate and retrieve objects in spaces too confined for human hands.
“It’s been a dream of mine for many, many years to design a new hand which departs from anthropomorphic hands,” says Aude Billard, a robotics and artificial intelligence researcher at the Swiss Federal Institute of Technology in Lausanne. “It’s allowing people to think out of the box, to rethink what it is to have a hand or finger.”
Billard and her colleagues used a type of machine learning tool called a genetic algorithm, which simulated how different combinations of robot traits would work together.That allowed the team to gradually optimize the design and come up with several blueprints for roughly hand-shaped bots that could crawl, grasp and carry objects. The researchers then built a five-fingered and a six-fingered version in the lab.
When attached to the mechanical arm, the robotic hand could pick up objects much like a human hand. the bot pinched a ball between two fingers, wrapped four fingers around a metal rod and held a flat disc between fingers and palm.
But the bot isn’t constrained by human anatomy. The fingers bend backward just as easily as forward, allowing the robot to hold objects against both sides of its palm simultaneously. It can even unscrew the cap off a mustard bottle while holding the bottle in place.
The study “is a beautiful example of what you can achieve if you approach robotic design without being weighed down by all the constraints of the human factor,” says Matei Ciocarlie, a mechanical engineer at Columbia University who wasn’t involved in the research.
When the robot was separated from the arm, it was most stable walking on four or five fingers and using one or two fingers for grabbing and carrying things, the team found. In one set of trials with both bots, the hand detached from the robotic arm and used its fingers as legs to skitter over to a wooden block. Once ther, it picked up the block with one finger and carried it back to the arm.
The crawling bot could one day aid in industrial inspections of pipes and equipment too small for a human or larger robot to access, says Xiao Gao, a roboticist now at Wuhan University in China. It might retrieve objects in a warehouse or navigate confined spaces in disaster response efforts. It might even work as a prosthetic hand — though Billard says further research is needed to understand how human brains would control and respond to limbs that don’t match human anatomy.
