Trending Science: Researchers develop robotic hand that can feel things

Until now, robotic prosthesis had one hurdle it couldn’t overcome: the sense of touch. Enter the LUKE Arm, a Star Wars-inspired prototype version of a robotic arm that can be linked up to the wearer’s nerves.

In a new study published in the journal ‘Science Robotics’, American biomedical engineers at the University of Utah report that the arm can now also produce an ability to feel. They explain how the arm revived the sensation of touch for Keven Walgamott, a real estate agent from Utah who lost his left hand and part of his arm in an electrical accident 17 years ago. He was one of seven subjects who tried the arm during clinical tests.

Helping amputees feel again

The prosthetic arm was in development for 15 years. Thanks to modelling and mathematics, it’s now considered a success. The LUKE Arm uses wires implanted under the arm that connect to a computer to signal the arm to move. Sensors on the hand send signals to the wires that replicate the feeling of clasping an object. The LUKE Arm has 100 microelectrodes that are connected to the upper arm’s nerves.

“A lot of people think of touch as one sense, but touch is actually comprised of many different senses,” Jacob George, a biomedical engineering doctoral student who led the study, told ‘Scientific American’. “There are sensors in your hand for pain, for temperature, for vibration, for pressure—and so what we’re doing is identifying each one of those little sensors.”

Walgamott was able to handle grapes, hold an egg without cracking it, text on his phone, and even feel his wife’s hand in his. The hand moves with his thoughts. For example, when picking up the egg, Walgamott’s brain could tell it not to squeeze too hard. The technology mimics the way his human hand feels objects by sending the appropriate signals to his brain.

“It almost put me to tears,” Walgamott said in a University of Utah news release after using the LUKE Arm for the first time in 2017. “It was really amazing. I never thought I would be able to feel in that hand again.”

Bionic hand that feels more natural

“We changed the way we are sending that information to the brain so that it matches the human body. And by matching the human body, we were able to see improved benefits,” George told ‘CNN’. “We’re making more biologically realistic signals.”

“Just providing sensation is a big deal, but the way you send that information is also critically important, and if you make it more biologically realistic, the brain will understand it better and the performance of this sensation will also be better,” said Gregory Clark, study team leader and associate professor at the university’s Department of Biomedical Engineering. “One of the first things [Walgamott] wanted to do was put on his wedding ring. That’s hard to do with one hand,” Prof. Clark added. “It was very moving.”

A fully portable version of the prototype that doesn’t need a computer connection is being developed. The team hopes that by 2021, three study participants will be able to take their LUKE Arm home.