A bionic arm is a prosthetic limb that uses advanced technology to simulate the form and function of a human arm. Equipped with sensors, motors, actuators and microprocessors, bionic arms give wearers the ability to control their movements through electrical signals generated by muscle contractions. They can be used to perform all kinds of daily tasks, whether that be carrying grocery bags or playing a musical instrument.
Bionic Arm Definition
A bionic arm is an artificial limb with electronically controlled moving parts. They are typically made out of materials like carbon fiber and silicone, and often include myoelectric sensors and motors.
Like any other prosthetic limb, bionic arms are designed to replace a missing body part lost to trauma, medical conditions or congenital defects. But they enable users to make more intuitive, precise movements, surpassing the capabilities of standard prostheses to enhance the quality of life for those who are missing a limb.
“Motor functions — even something as simple as grasping an object — are directly tied to a person’s independence and quality of life,” Inseung Kang, an assistant professor of mechanical engineering at Carnegie Mellon University and leader of the MetaMobility Lab, told Built In. “Developing more natural and intuitive systems, such as bionic limbs, can significantly enhance the lives of individuals with impairments, allowing them to perform everyday tasks with greater ease and confidence, ultimately improving their autonomy and overall well-being.”
What Is a Bionic Arm?
Bionic arms are devices that use a combination of sensors, actuators and microprocessors to convert muscle contractions into movement, providing users with capabilities similar to a natural human arm. Often constructed with materials like carbon fiber, titanium and silicone, these prosthetic limbs always include a hand, and can be customized with additional modular components — such as shoulders, elbows or wrists — to meet the specific needs of the wearer.
Bionic arms usually come with features like multiple grip styles, wrist rotation and fine motor functions that lets users perform tasks ranging from opening jars to handling fragile objects. Some of the most advanced models even incorporate sensory feedback systems, enabling users to feel pressure, temperature and texture. The goal is to restore as much natural functionality to the wearer as possible, helping them confidently engage in daily activities.
How Does a Bionic Arm Work?
For a bionic arm to work, myoelectric sensors are placed on the user’s residual limb, typically around the muscles. These sensors detect electrical signals produced by the user’s muscle contractions and transmit them to a microprocessor within the device, which interprets the information and moves the motors and actuators accordingly. From the gathered data, muscle patterns can be identified and programmed into a machine learning model, Kang explained, which then classifies the user’s intended actions. “Based on this classification, the bionic arm is controlled to carry out various manipulation tasks,” he said.
Users can control the movement of their bionic arm by flexing specific muscles or making subtle muscle contractions detected by electrodes placed on the skin. The arm may also feature other types of sensors, such as accelerometers and pressure sensors, to enable more precise control and provide feedback to the user.
“In some cases, force sensors are also placed on the fingertips of the bionic arm,” Kang said, allowing the artificial limb a better “feel” for objects by detecting the amount of force being applied. “This feature helps to regulate the force exerted, preventing damage to objects.”
While bionic arms aim to provide fluid, functional movements, each model will vary in its ability to recreate tasks like gripping, lifting and manipulating objects.
Bionic vs. Prosthetic Limbs: What’s the Difference?
Both bionic and prosthetic limbs are artificial devices designed to replace human appendages for those who have lost limbs due to an injury, disease or congenital condition — a challenge faced by nearly 2.3 million Americans.
Historically, prosthetic limbs, or prostheses, were simple, fixed devices often used for cosmetic purposes. The earliest known prostheses are wooden, leather and papier-mâché toes from Egypt that date back 2,000 to 3,400 years ago. Today, these devices are more functional, serving as body-powered mechanical appendages that move in sync with a user’s body.
Bionic limbs, on the other hand, are made up of electronic components aimed at restoring the natural, biological movements and capabilities of the lost appendage. These devices are often equipped with sensors, actuators and computer processors that collect sensory feedback from the wearer, while simultaneously responding to their surrounding environment. Essentially, bionic limbs are myoelectrically powered prostheses, or prosthetic limbs powered by the electrical impulses generated by muscles in the body.
In short: While all bionic limbs can be considered a form of prosthesis, not all prostheses are bionic.
What Can a Bionic Arm Do?
Bionic arms can perform a variety of tasks that closely mimic the natural movements of a human hand. These include:
Gripping and Holding
Most bionic arms come with a multi-grip feature that enables the user to switch from one grip or hold pattern to another just by flexing a different muscle. This allows users to easily transition from holding a cup or a bag to grasping a doorknob, for example.
Wrist Rotation
By mimicking the natural rotation of the human wrist, bionic arms enable users to perform a wider range of tasks with increased flexibility, whether it be stirring a pot, unlocking a door or adjusting the angle of a tool. Having a fully functional wrist also makes the arm more versatile, allowing for more fluid transitions between activities that require different hand positions.
Fine Motor Skills
Tasks like typing, writing, buttoning up a shirt and using handheld tools or electronic devices require precise, hand-eye coordinated movements with the small muscles in your hands, fingers and wrist. The mind-body connection involved in operating a bionic arm enables users to regain fine motor skills and complete such tasks with greater ease.
Sensory Feedback
Although most bionic arms do not have a sense of touch, some of the most advanced models have sensory feedback systems that allow users to feel pressure, temperature and texture through the prosthesis. This can help users gauge the force needed to grip particular items without damaging or dropping them, and enables them to distinguish between different objects.
Enhanced Social Interaction
Although it may seem like a small feat, bionic arms enable users to engage in social traditions, like shaking hands, giving high-fives or embracing someone. These capabilities contribute to a sense of normalcy and connection with others.
Restored Functionality for Everyday Tasks
Perhaps the most important function of a bionic limb is restoring a sense of “normalcy.” Users want to be able to do the things they used to do and move through the world effortlessly, without having to think twice, find a workaround or avoid an activity entirely. Bionic arms enable users to independently perform essential daily activities like eating, dressing and grooming, as well as pursue hobbies such as playing an instrument or exercising, in a way traditional prostheses can’t.
Examples of Bionic Arms
Below are some of the foremost bionic arms currently in development.
The Hero Arm by Open Bionics
The Hero Arm is a lightweight, 3D-printed bionic arm made for those with below-elbow limb loss. With six grip patterns, 180-degree wrist rotation and customizable aesthetics, the Hero Arm is widely recognized as one of the leading bionic arms — not just for its features, but for its affordability and accessibility, as it is one of the few options available to both adults and children as young as eight. Plus, the device is fabricated with a rugged thermoplastic material known as Nylon 12, so it’s able to lift about 17 and a half pounds while weighing just 12 ounces.
Ottobock’s Myoelectric Prostheses
The Bebionic Hand, DynamicArm Plus and Michelangelo Hand from Ottobock are advanced, upper-limb myoelectric prostheses, which means these battery-powered devices are controlled by the user’s own muscle signals. For this to work, electrodes placed on their residual limb pick up nerve impulses, then use them to control the motors in the prosthetic hand. The Bebionic Hand, for example, is a lifelike bionic arm and hand with 14 grip patterns that allow users to carry out everyday tasks like handling utensils to eat a meal, carrying grocery bags in from the car and switching on lights.
The LUKE Arm by Mobius Bionics
The LUKE Arm is the only commercially available bionic arm with a shoulder configuration, according to its maker’s website, meaning it is designed for those with little to no residual limb. Powered by lithium-ion batteries, the prosthesis is controlled by several standard input methods — EMG electrodes, pressure switches and rocker switches — as well as Mobius Bionics’ inertial measurement unit device worn on the user’s shoe. Its modularity makes the LUKE Arm suitable for those with partial or full upper limb amputations or congenital defects.
i-Limb Quantum by Össur
The i-Limb Quantum is a multi-articulating myoelectric hand that allows users to switch between 36 different grips through a gesture. Its carbon-fiber-based body is lightweight and durable, while its five, independently motorized fingers are built out of titanium. It also features electronically powered thumb rotation, which gives the bionic arm enough dexterity and coordination to handle activities like typing on a keyboard, preparing food and playing musical instruments.
The Future of Bionic Arms
Bionic arms are giving those with limb-loss the ability to perform everyday tasks, but their movements and tactile capabilities are still not as fluid as a natural limb. The next wave of bionics will incorporate emerging technologies from fields like robotics, artificial intelligence and neuroscience to optimize control, making dynamic movement “as simple and intuitive as possible for the user,” Michaela Buhl, a team lead of upper limb prosthetics at Ottobock, told Built In.
Some approaches involve embedding sensors directly in the brain, like Neuralink’s brainchip, while others, such as Silicon Valley startup Atom Limbs, focus on non-invasive neural interface techniques to create mind-controlled robotic arms. And some researchers suggest that achieving more natural movement in bionic arms could actually reduce the mental effort required by the user. This means putting a greater focus on components like haptic feedback systems, as seen with the headset-enabled Zero Arm, and making efforts to mechanize the body’s ability to sense itself — a function known as proprioception. Researchers at the Cleveland Clinic are now integrating this into bionic arms to make them respond more intuitively to stimuli.
But there are significant obstacles in the way. Aside from the inevitable regulatory hurdles and public funding setbacks, Buhl noted that battery technology is quite literally weighing down what wireless electronic devices can do. And achieving the proper fit remains a challenge, as prosthetics need to be both comfortable and functional for users to want to wear them.
“For good control of a bionic arm, the fit of the socket is crucial,” Buhl said, noting that a universal socket standard that suits the incongruous nature of stump surfaces has yet to be developed. She predicts that 3D printing will play a major role in developing highly customizable, lightweight bionic limbs in the near future. “Take shoes as an example. If a shoe doesn't fit me properly or pinches me, then I won't wear it — it’s the same with a prosthesis.”
Still, perhaps the most pressing issue is affordability. As Britt Young, a writer and bionic arm user herself, pointed out in a 2022 article, the “well-intentioned engineers” that make up the bionics industry seem to be so occupied with building high-tech, superhuman limbs that they’ve lost sight of creating devices that are actually accessible to the people who need them. The average myoelectric limb costs more than $20,000, with prices ranging from $8,000 to as much as $100,000 or more.
“It’s time to ask who prostheses are really for,” she wrote, “and what we hope they will actually accomplish.”
Frequently Asked Questions
How much does a bionic arm cost?
The cost of a bionic arm varies depending on its features and level of customization. The Hero Arm by Open Bionics is considered to be one of the most affordable bionic arm products on the market today, with prices ranging from $10,000 to $20,000, depending on a user’s location and warranty package. However, other bionic arms can cost upwards of $100,000.
Is it possible to have a bionic arm?
Yes — there are dozens of bionic arms commercially available today.
Can people with bionic arms feel?
Sort of. More advanced bionic arms are equipped with haptic feedback systems that give users a sense of touch or pressure. However, the experience is quite limited in comparison to a natural limb, though researchers are working to improve this.
How long do bionic arms last?
An upper limb prosthesis will last several years with regular maintenance. The average lifespan ranges from three to five years, according to the Orthotic and Prosthetic Centers of Florida.
