Future of Bionic Limbs: Will Prosthetic Singularity Create Superhumans

Over the last decade, we’ve witnessed a lot of small but continuously progressive innovations in developing high-tech prostheses. The best part of this incremental revolution is that it isn’t just restricted to the social elites who can afford it. Technologies such as 3D printing have also made complex bionic limbs available to the less economically fortunate, making the future of bionic limbs one to watch closely

But where do we go from here? Like every other technological marvel, the future of bionic limbs is never a straight path. It branches out into different disciplines, with each having an evolutionary path of its own.

… And perhaps some of these are destined to change society as we know it.

Most Promising Elements of The Future of Bionic Limbs

The mechanical design of artificial limbs, as well as the interfacing method with the human user, are equally important aspects of its advancement. As such, the most notable techniques and technologies for the future of bionic limbs are:

• Brain-computer Interfaces – as we go beyond myoelectric applications and into more and more advanced methods of wiring brains directly to electronic devices, there will eventually be a period where bionic limbs and BCI/BMI technologies meet. After all, the most natural way to signal an arm to move, artificial or not, is via electronic signals. With our current level of development and with certain commercial innovations like Neuralink, it is conceivable that a true prototype will appear before the end of the current decade.

• Recreating sensory stimulation – next to sending commands and signals directly from the brain, restoring one’s sense of touch for the bionic arm or leg (even with a rudimentary system) can go a very long way in providing very precise control and movement. After all, we can hold and move around an empty plastic bottle with perfect precision and without crushing it because we can feel the object. Many research institutions are already tackling this very challenge, and the approaches to reproducing the human skin’s natural sense of touch are very wide and varied.

• Machine learning – a much more near-term objective would be instead to hand over the analytical process of movement, coordination, and positioning to artificial intelligence. More critically, however, machine learning could help accurately analyze the complex data gathered from touch sensory input. There have been a couple of foundational research projects looking into the feasibility of the concept. But so far, most of the pilot experiments concentrate solely on the prosthetic design. Therefore, this is more within the realm of robotics research at the moment and will likely remain so for the next few years ahead.

• Targeted Muscle Reinnervation – this is a post-amputation medical procedure that involves rerouting severed or injured nerves to new muscle targets. When combined with custom-made prostheses, it forms the backbone of an easier, generally more intuitive interfacing method. The biggest hurdle for this method is the accuracy of the sensors and the training required before the user has full control over the bionic limb’s sensory input. Better worldwide standardization across medical facilities could catalyse a more universal prosthetic design system in less than a decade.

• Osseointegration – this is a rather old concept of directly grafting metallic rods into the bone for various purposes. In the field of prosthetics, especially for the future of bionic technology, this procedure becomes a preliminary step towards creating an instantly attachable/detachable artificial body part. Unfortunately, in terms of technological research, we can’t really expect any significant breakthroughs on this front. But hopefully, in the next decade, we should finally be able to get a better data set on the long-term effects of using bionic limbs developed with this procedure.

• Artificial muscles – though still highly impractical for any bionic limb experiment or application, artificial muscles remain very promising in terms of changing the core locomotive system of bionic limbs. It’s exactly what the name suggests: a composite, sometimes metallic fibre that, when strung together and given molecular stimulation, contracts like an actual human muscle. It may be in its very initial stages now, but we hope to see at least a basic bionic limb prototype that could showcase its potential in the next ten years.

When Can Bionic Limbs Perform Better than Natural Limbs?

Spoiler alert: bionic limbs are actually better than human limbs already! Okay, to be fair, at this point in time we are still very far from the imagined futures of science fiction. But, that doesn’t mean bionic limbs can’t provide significant enhancement compared to the original flesh and blood limbs right now.

In fact, there are already a few things that come to mind that can prove this, such as:

• The bionic limb doesn’t have to be a direct analogue of the lost body part. The user can still technically hook the same myoelectric sensors and input electrodes to control something else that might not be using hands or fingers. Jason Barnes, for example, uses controlled muscle twitches on an experimental robotic drumstick arm to execute programmed (pre-arranged) commands on two attached wooden drumsticks. He can pretty much perfectly recreate how the human finger uses drumsticks this way and has enhanced the experience even further.

• We already have the base standard for the perfect pair of bionic legs that are indistinguishable from regular limbs today. After all, the legs, feet, and toes have a much more predictable movement method and range than arms, hands, and fingers. Once again, we refer to Hugh Herr’s valuable research into programmable prosthetics as an example of what the future of bionic limbs looks like. Unlike older styles of design, his perfected artificial limbs allow users to walk or do leg-related tasks with an astonishingly accurate level of ability.

• Restoring the sensation of touch or creating a sort of “bionic skin” turns out to be a very important element for future bionic limbs. Using a natural hand, we can often simply estimate the right quantity of force and distance through touch and then focus our eyes on another target objective. Prosthetic users can’t do this and must manually observe the artificial hand know what it is doing. By just restoring the sense of touch alone and combining it with current sensory input methods, it is expected that we can immediately improve the dexterity of current bionic limbs. The only caveat right now is that the concept and disciplines to achieve this are so varied and scattered. 

Would You Willfully Replace Your Limbs with Bionic Ones?

The philosophical implications of bionic limbs being much better than natural ones are beyond the scope of this article. That said, we believe that it is just a matter of time before the inevitable question needs to be answered. At that point, which we shall call the “prosthetic singularity”, bionic limbs would have become much more powerful, useful, and reliable than their original counterparts. In a future like the setting of Cyberpunk 2077, how can you even resist? If the norm is to enhance yourself with various electronics and machinery, wouldn’t the normal ones be considered disabled?

But then again, there is always the old saying, “if it ain’t broke, don’t fix it.” Perhaps the simplest reason not to fall into the temptation of enhanced bionic limbs is that you still have perfectly functioning ones. A mundane, everyday blessing that millions of other people around the world have yet to normally enjoy again for the next few decades.

Featured image credit by Marvel Studios.