How does a bionic arm work?

How does a bionic arm work?

Bionic arms such as the Hero Arm are worn by people with upper limb differences, like Kate, Dan and Raimi. Bionic arms work by picking up signals from a user’s muscles. When a user puts on their bionic arm and flexes muscles in their residual limb just below their elbow; special sensors detect tiny naturally generated electric signals, and convert these into intuitive and proportional bionic hand movement. The bionic hand is controlled by tensing the same muscles which are used to open and close a biological hand. To close the Hero Arm’s hand, and perform the selected grip, imagine flexing the wrist inwards while pulling the fingers into the heel of the hand. To open the hand, imagine extending the wrist with an outstretched palm.

Cool, so what’s the technology?

Most Hero Arm users tell us that they’re able to control their bionic hand within just ten minutes, whereas some require a little more rehabilitation to strengthen their muscle sites. The technology is known scientifically as electromyography, and the special sensors in bionic arms are electromyographical, or EMG, electrodes. Myoelectric bionic arms are plug and play, meaning users can take their bionic arm on and off with ease. The Hero Arm has an adjustable dynamic socket for maximum comfort. No surgery is required; we simply identify a user’s strongest muscle sites and take a 3D scan or cast of their residual limb before custom building a Hero Arm.

Raimi picks up tile, wearing Iron Man Hero Arm Cover

Getting to grips with bionic arms

Grab, pinch, high five! Bionic arms like the Hero Arm give users proportional control and multiple grip modes. The bionic hand will move more slowly when your muscles are tensed gently, and will move more quickly with a firmer tense. This control can be useful for manipulating small or delicate objects, such as eggs or ball bearings. The Hero Arm has up to six different grips, and these are grouped together in pairs to make switching between them quick and easy. To switch between the different groups, users press the button on the back of the hand. The groups are ‘fist and hook’, ‘tripod’ and ‘pinch’. To toggle between two grips in a group, users hold an open signal for more than one second. Prosthetists are also able to customise grips for a users through an app. 

Star Wars BB8-themed prosthetic arm using a catapult

Discover the Hero Arm

The Hero Arm is now available through prosthetic clinics in the UK, USA and Europe. If you're a below-elbow amputee and interested in getting a Hero Arm, register your interest and we'll reach out to you with information about your nearest prosthetics clinic. Your bionic journey begins here.