These prosthetics break the mold with third thumbs, spikes, and superhero skins

Many mornings, Dani Clode wakes up, straps a robotic thumb to one of her hands, and gets to work, poring through reams of neuroscience data, sketching ideas for new prosthetic devices, and thinking about ways to augment the human body. Clode works as a specialist at the University of Cambridge's Plasticity Lab, which studies the neuroscience of assistive devices.

But she also creates prosthetics, ones that often fall outside the conventional bounds of functionality and aesthetics. Her designs include a clear acrylic forearm prosthetic with an internal metronome that beats in sync with the wearer's heart and an arm made with rearrangeable sections of resin, polished wood, moss, bronze, gold, rhodium, and cork.

Clode's current project, one that is also helping her get work done, is a third thumb" that anyone can use to augment their grip. The flexible device is powered by motors and controlled using pressure sensors in the wearer's shoes. Volunteers have learned to use it to unscrew a bottle, drink tea, and even play guitar. She hopes that one day the thumb (and devices like it) might help everyone from factory workers to surgeons perform tasks more efficiently, with less strain on their own bodies.

Traditionally, prosthetics designers have looked to the human body for inspiration. Prosthetics were seen as replacements for missing body parts; hyperrealistic bionic legs and arms were the holy grail. Thanks to sci-fi franchises like Star Wars, such devices still have a vise grip on our collective imagination. For better or worse, they've shaped how most people conceive of the future of prosthetics.

But Clode is part of a movement in alternative prosthetics, a form of assistive tech that bucks convention by making no attempt to blend in. Instead of making devices that mimic the appearance of a normal" arm or leg, she and her fellow designers are creating fantastical prosthetics that might wriggle like a tentacle, light up, or even shoot glitter. Other unconventional prosthetics, like the blade legs favored by runners, are designed for specific tasks. Designers believe that these devices can help prosthetics users wrest back control of their own image and feel more empowered, while simultaneously breaking down some of the stigma around disability and limb differences.

But even as alternative prosthetics gain visibility, they are shadowed by an uncomfortable fact: prosthetics are still accessible only to a small percentage of those who could benefit from them. In a world in which many people who want a prosthetic can't afford one, advocates are searching for a middle ground where accessibility, style, and substance overlap.

Prosthetic devices are old and deeply human. The earliest known artificial limbs are from ancient Egypt: two sculpted toes, one found strapped to the right foot of a mummy, which date back 2,500 to 3,000 years and bear unmistakable marks from corded sandals.

Ancient people crafted and wore prosthetics for myriad reasons-some practical, some spiritual, some tinged with ableist logic. Most were designed to blend in, but some intentionally stood out. When the Roman general Marcus Sergius Silus lost his hand in the Second Punic War, he reportedly ordered up an iron replacement. At least one medieval Italian man appears to have replaced his hand with a knife.

Instead of making devices that mimic the appearance of a normal" arm or leg, Clode and her fellow designers are creating fantastical prosthetics that might wriggle like a tentacle, light up, or even shoot glitter.

The impulse to customize one's prosthetic makes sense to Victoria Pitts-Taylor, a professor of gender studies at Wesleyan University who has researched body modification in culture, medicine, and science. Whatever we're doing to our bodies, we're not doing it to them in a social vacuum," she says. Veterans may want to express their identity with a physical tribute to their military service, while artists may want to experiment with color and pattern.

In Pitts-Taylor's view, everyone in society is expected to modify their body in some way-by getting certain haircuts, for example, and wearing particular clothes. When we are able to find ways to modify our bodies that reflect our sensibilities and our sense of ourselves, it feels really good," she says.

The top half of Dani Clode's Materialise" arm is made of rearrangeable segments composed of unconventional materials, including resin, polished wood, moss, bronze, gold, rhodium, and cork.COURTESY OF DANI CLODE

The disability rights movement, which took off in the United States alongside the civil rights and queer liberation movements of the 1960s, has been pushing for broader prosthetic acceptance for decades. Early activists took to the streets wearing minimal devices such as split hooks (or no devices at all), while later ones glued sparkling disco-ball mirrors to their prosthetics. The idea being: I'm not going to change my body to suit conventional standards," says David Serlin, a disability and design historian at the University of California, San Diego.

But the modern medical system is not set up to take things like self-expression or identity into account. Today, when big medical-device companies design assistive technology, they still often approach it from a curative" perspective, an approach known as biomedicalization.

The purpose of biomedicalization is to normalize bodies," says Pitts-Taylor. The aim is to produce a body as close to the ideal" as possible, and in Western medicine, that ideal is often white, gendered, and able-bodied.

These priorities have fed into a long legacy of ineffective or uncomfortable prosthetics that don't really meet individuals' needs (let alone align with their sense of self). For example, prosthetic hands typically come in just three sizes-male," female," and child." But a lot of people fall somewhere in between these measurement ranges or outside them altogether.

Such limited choice can create an awkward mismatch between their artificial and biological limbs. For people of color, selecting a device can be even more jarring, as some prosthetics manufacturers regularly distribute only a few skin-tone options to clinics and hospitals.

People missing an upper limb still face social pressure to wear a high-tech, five-fingered bionic device, whether or not it's a good fit.

Prosthetics users are also not a monolith, says Clode. Individuals have unique levels of touch sensitivity, based on things like the concentration of nerves in their residual limb and whether they experience phantom limb sensations. These factors can greatly affect their willingness and ability to tolerate a prosthetic, which must fit snugly over this sensitive area.

And a person born with a limb difference, for example, can have a vastly different experience from an amputee. Someone who loses a limb later in life may find comfort in wearing an assistive device. But many people who are born missing an arm are extremely proficient at performing everyday tasks with their residual limb, to the point where clunky prosthetics just get in the way.

A pioneer in the design of prosthetics aimed mostly at utility was Jules Amar, who crafted devices for soldiers who had lost limbs in World War I. His designs broke with the traditional approaches in that they were optimized for specific tasks. Amar gave his patients limbs that terminated in pliers, for example, with the goal of reintegrating the shell-shocked young men back into productive" society. By most accounts, his approach worked-many vets were able to find jobs on farms and factory floors, though some of Amar's contemporaries raised concerns about exploiting disabled workers.

Today, prosthetics users can get fitted with far more high-tech solutions, like myoelectric devices-motorized limbs that convert electric signals from muscles in a residual limb into movement. But many people choose to forgo these complex robot-like limbs in favor of more specialized devices like Amar's, such as athletic blade legs or body-powered activity arms" with a swappable end. I have one of those, which I mostly use for working out," says Britt H. Young, a tech writer and PhD candidate at the University of California, Berkeley. In many ways, people who use those have greater satisfaction."

For a long time, one assumption underlying the development of medical devices was that a prosthetic that lines up with the brain's expectations would be inherently easier to operate (or, in research terms, embody"). When we think about embodiment, we think about something that is close to our body template," says Tamar Makin, a professor of cognitive neuroscience at the University of Cambridge who works closely with Clode to investigate how the brain adjusts to interfacing with artificial limbs. Makin's research confirms what prosthetics users have long intuited: our brains are actually very flexible in their ability to adapt to new limbs.

Prosthetics appear to occupy a space between object" and self." In a 2020 paper published in PLOS Biology, Makin's lab scanned the brains of prosthetics users and non-prosthetics users in an fMRI machine to see how particular areas in the brain respond to the presence of an artificial limb. The researchers initially expected to see similar patterns whether people used an artificial arm, a flesh-and-blood hand, or a tool for daily tasks. But this was not the case.

Prosthetics were not represented like hands," says Makin, but they were also not represented like tools." Instead, they seemed to trigger a unique neural signature-neither hand nor tool but a previously unknown thing. These patterns were consistent across different users, suggesting that most people can readily adapt to a wide variety of artificial-limb configurations, provided the device remains useful in their daily lives.

COURTESY OF NICHOLAS HARRIER

Lower-body prosthetics that don't look like conventional limbs are slowly gaining broader cultural acceptance, especially in the sports arena, where high-profile athletes like Aimee Mullins and Blake Leeper have helped catapult running blades into the spotlight. But people missing an upper limb still face social pressure to wear a high-tech, five-fingered bionic device, whether or not it's a good fit.

Jason Barnes wanted an upper-limb prosthetic of a very different kind. Barnes, a music producer and musician in Atlanta, grew up with a passion for drums. But in 2012, a work accident sent 22,000 volts of electricity surging through his right arm, and the limb was amputated below the elbow.

A few weeks after he got home from the hospital, he taped a drumstick to the end of his bandages and began relearning how to play. It wasn't long before he started building his own prosthetic arm from scratch with a drumstick built in. That was a lot of trial and error, because I had no idea what I was doing," he says. He ultimately found an approach that worked-a drumstick arm rigged with counterweights that he could manipulate using his shoulder and elbow, not dissimilar from Jules Amar's designs. Not long after, he enrolled in the percussion program at the Atlanta Institute of Music and Media.

But Barnes was still occasionally frustrated. In order to play in different styles-switching, for example, between complex jazz and swing rhythms-he had to stop to tighten or loosen his prosthetic. He wanted more seamless control.

Jason Barnes plays the keyboard while wearing a new myoelectric prosthetic, which he co-designed with Gil Weinberg's lab at Georgia Tech.ROB FELT / COURTESY OF GIL WEINBERG

He was introduced to Gil Weinberg, a music technology professor at Georgia Tech, whose group collaborated with Barnes to engineer a new myoelectric drumming arm capable of reading his muscle movements and executing much more subtle hits.

Then they took the design a step further, adding a second drumstick that could use machine-learning software to pick up on the rhythms of other musicians in the band. The idea was that the second stick sometimes would play something that's not under Jason's control," says Weinberg. That creates a kind of strange, intimate connection" between the musicians.

The new arm turned Barnes into a drumming superhero, enabling him to push beyond the limits of the human body with rhythms that no one else on the planet could touch. He even set a Guinness World Record for drumming speed in 2019. But after a while, he realized that it was easier to use a single stick.

Technologically, [the two-stick arm] is a great idea," Barnes says. But looking at it from a drummer standpoint, it kind of didn't make a whole lot of sense."

Barnes hasn't entirely given up on high-tech drumming assistance. He and Weinberg are currently designing a new myoelectric arm, one that combines the subtlety of the two-stick prosthetic with the creative autonomy offered by Barnes's body-powered arm. Which prosthetic he uses depends on the day and what he's trying to play.

Not every nontraditional prosthetic is designed strictly for function; some are high fashion. Viktoria Modesta, a Latvian-born artist, has long been fascinated by science fiction and retro-futurist aesthetics. When she began wearing a prosthetic, she decided to dispense with the traditional mold entirely. For me, it was a kind of taking back control and changing the narrative," she says.

Modesta's left leg was injured at birth, leading to years of surgery and medical complications. She underwent an elective amputation at age 20 and says the relief was almost instant.

Before the surgery even took place, she started imagining her prosthetics. After the operation, she collaborated with Tom Wickerson and Sophie de Oliveira Barata of a design initiative called the Alternative Limb Project (of which Clode is also a member) to make one of her visions a reality: a gem-encrusted lower limb inspired by Hans Christian Andersen's classic fairytale The Snow Queen." My leg went from life sentence to an object of love and desire," she recalls.

You should be able to experiment with not just your wardrobe but your limbs, your power, your everything."

Viktoria Modesta

Since then, Modesta, a musician, model, and self-described bionic pop artist, has helped bring scores of futuristic limbs to life. You can see her featured in a promotion for Rolls-Royce with a leg that houses a Jacob's ladder, arcs of electricity zinging up her shin; walking the runway with a chrome-plated femur; floating in microgravity with a leg like a metallic tentacle. In her viral 2014 music video Prototype," she sports one of her most iconic looks: the Spike leg, an obsidian dagger whose design, she says, came to her in a dream.

Controlling the look of her prosthetic has helped Modesta fully embrace her body, a kind of self-expression that she believes should be available to everyone. You should be able to experiment with not just your wardrobe but your limbs, your power, your everything," she says. But while accessibility is slowly improving, she recognizes that for many people across the globe, custom prosthetics simply aren't an option yet.

Viktoria Modesta models the Spike leg, whose design came to her in a dream.COURTESY OF VIKTORIA MODESTA

Artificial limbs are pricey. Even with great insurance, a prosthetic leg can cost anywhere from $5,000 to upwards of $80,000, depending on its complexity. What's more, the limb's parts have to be replaced as they wear out, which costs thousands of additional dollars-some knee joints alone can run $30,000. Some insurance will cover part of it," says Young. But most providers will not cover a significant part."

And that's without any sort of aesthetic customization. Prosthetics manufacturer Ottobock's online store, for example, offers a significantly wider range of skin tones than it provides to clinics. The options are appealingly presented to the user like designer paint swatches-but the online-only shades have to be custom ordered and typically aren't covered by insurance, says Nicholas Harrier, a certified prosthetic technician based in Michigan.

Harrier, who lost a leg in his mid-20s from an infection following childhood cancer, aims to crack open the doors and make aesthetically customized devices just a little more accessible. He started flexing his creative muscles about a decade ago, when he came across some of the designs that the Alternative Limb Project helped create for Viktoria Modesta. Intrigued, Harrier reached out to the project but never heard back. So he decided to try making custom covers himself, beginning with one for his own prosthetic leg.

He created one that was like something out of a William Gibson novel, complete with futuristic wiring and a multihued circle of LEDs glowing in its center. Almost as soon as Harrier put the finishing touches on it, he started building custom covers for others. He has since crafted dozens of them, using acrylic and silicone, metal and resin, paint and light.

These two prosthetic covers were designed by Nicholas Harrier.

Each piece is totally unique and tailored to the individual. One is studded with steampunk clockwork; another replicates the look of Cyborg from DC Comics. Harrier's work does not change how a prosthetic functions, just how it looks. He has one rule: all of his covers are 100% free, built from materials he buys and enabled by the flexible schedule that his boss grants him. I will not charge a person for this," Harrier says. In the future, he hopes, services like his will be standard practice for any prosthetics clinic: It needs to become normal. So giving them away is crucial."

A few larger businesses are working to make cosmetic prosthetic covers more accessible as well. Companies like the UK's Open Bionics are creating affordable 3D-printed options, such as the hero arm," whose patterns are pulled straight from Marvel movies. Many are marketed toward kids as a way to build self-esteem.

Only around 10% of folks living with limb loss worldwide have access to a prosthetic device, according to the World Health Organization. And need isn't the same for every demographic. In the United States, for example, Black people are nearly four times more likely to undergo amputation.

Young believes that people who want a prosthetic device of any kind should be able to buy and maintain one without breaking the bank. The biggest impact we can have on prosthetics is not a new approach to design, but medical-device reform," she says. At the same time, she adds, we shouldn't shy away from trying to improve the design possibilities of prosthetics. People need to feel comfortable in their own bodies as a human right," she says.

Reforming the prosthetics industry is a multifaceted undertaking that involves improving access, developing devices that work well for whoever wants them, and affirming basic dignity. It's not only function or only aesthetics," says Serlin. It can be, ideally, both."

Joanna Thompson is a freelance science writer based in New York.