Researchers from the University of Utah are developing a system that allows amputees to control a bionic arm using just their thoughts. What’s more, the hand portion of the limb enables them to ‘feel’ objects that are being touched or grasped. Known as the Luke Arm (a tribute to Luke Skywalker’s prosthetic limb), the robotic arm mimics the way a human hand feels different objects by sending signals to the brain. An amputee wearing the arm can sense how hard or soft an object is, letting them understand how best to handle said objects.
The Luke Arm itself has been in development for over a decade and is made of servo motors, actuators, rotors, flexors, and other parts, all wrapped in a silicone skin. It gets its power from an external li-ion battery and is wired to a PC to translate nerve impulses into actions.
To control the arm, a bundled array of 100 microelectrodes are surgically implanted into the wearer’s nerves in the forearm or shoulder, which are then wired to a PC. The array passes the signals from nerve impulses to the PC that translates them into digital signals that move the hand and limb.
The sense of touch is provided by a series of sensors housed in the robotic hand, which send signals to the microelectrode array, then on to the computer, where algorithms modeled after how the human brain perceives impulses from touching or grasping objects. Those signal patterns are then introduced back into the system that gives the user a clear sense of touch.
The team is already working on a way to make the Luke Arm portable, where it doesn’t need to be wired to a computer. Moreover, they are looking at ways to incorporate other senses, such as perceiving different temperatures and even pain.