Difference Between Bionic and Prosthetic: Supercharge replacements Limbs with More than Just Sensors

Bionic and Prosthetic in the context of replacements of human limbs can sometimes be misunderstood as being the same thing. Bionics incorporate natural movements, whereas prosthetics simply restore the physical portion of a lost body part. In other words, bionic limbs are the “smarter” prosthetics and are therefore considered a subcategory.

Along with technology, there are other fundamental attributes that make the two terms distinct. After all, there are just as many disciplines within bionics as there are priorities and objectives with designing prosthetics in general. Some of them may even be completely unrelated to bionics altogether.

Comparative Pros and Cons of Bionics and Prosthetics

(One is a field, the other is an object)

1. Complexity level

Bionics is inherently the more complex concept. Standard prosthetics do not require sensors or any type of multi-stage calibration to coordinate the artificial body part’s movement, and as a result, are typically made simpler. That said, depending on the objective of the prosthetic, the mechanical design can still be just as intricate as any current generation bionics. This is especially true when one-for-one human limb design is no longer necessary, something that bionic limbs strictly need to adhere to (both because of design principle and ‘natural’ use).

2. Ease of use

The difference between bionic and prosthetic in this case requires assessing relative simplicity. On the one hand, bionics should win the category because it aims to restore normal use of a lost body part. But as a counterargument, prosthetics can also be easy to use if they are designed with mechanical innovations in mind (tailor-made for the specific individual, of course). One notable example is Mr. Ian Davis, who has been documenting his prosthetic hand design online. It doesn’t have sensors, and it’s not infused with the latest robotics tech. But his simple mechanical set of fingers can still do what a natural hand should do with (somewhat) minimal effort.

3. Availability

By definition alone, prosthetics wins this one, hands down. Bionics is technically a subcategory of prosthetics, after all. Moreover, unlike the typical replacement prosthetic, the commercialization of bionics isn’t really that prevalent yet. The industry definitely exists, but it is pretty much on a made-to-order basis. Other innovations such as 3D printing cannot really be applied directly to bionics either, as the level of technology required is usually much higher. You either have to be a specialist in making prosthetics already or be part of a larger institution (business or academic) that caters to disability-related medical needs.

4. Practicality

This depends on the type of limb you are trying to restore. For less articulate body parts, such as legs and feet (that also have a predetermined range and type of moment), bionics have a strategic edge. But for arms and hands, practical usage of prosthetics and bionics are… well they’re actually kind of the same. Bionics may have the upper hand with its natural-like use, but dexterity isn’t really that much different from a cleverly designed regular prosthetic. So in this criterion, we’re still pretty far away from the full optimization of movement for individual artificial limb components.

5. Overall cost

Prosthetic limbs are simply cheaper and faster to adopt than bionic limbs. If complexity level and ease of use are to be completely ignored, technically the simplest of any body-powered artificial appendage-like tool can be included in this category. Even for highly crafted prosthetics, the procedures involved, calibration, custom-design of sensors, and the potential for servicing the bionic limb for several months leave bionics at a high-cost disadvantage. However, this can be mitigated at least with the use of other technologies such as 3D printing, which is the main objective of companies like Open Bionics.

Where Bionics Matter

(Function restoration, intuitive use, medical forefront)

Despite the deployment and availability issues of bionics, they are still invaluable to the overall field of physical disability medicine. For one thing, their technologies are capable of catering to more and more specific disability cases, for which the solutions developed can then be used as a template for future similar cases. It also allows amputees to get on their lives and continue their work or careers with relatively little change.

One example of this is the common “digital rehabilitation” strategy employed by companies like Esper Bionics. On paper, at least, they focus on training the user with an ever-evolving level of signal detection and movement prediction algorithms to increase their effective use over time. It may not have the exact dexterity of the previous human hand right now, but it will soon improve to be as close as its mechatronic design possibly could. And in the case of our never-ending reference to Hugh Herr, this can even transcend eventually into a “superpower”.

Then again, some patients with better access to more advanced medical options would simply choose the current best methods, which by default points directly to the use of current generation bionics. In that case, pushing boundaries defaults to be a matter of time and research (to hopefully become cheaper and more available in the future).

Where (Simpler) Prosthetics Matter

(Deployment, ease-of-use, lower cost)

For those simply looking for a quick, cheap replacement for a lost limb, regular prosthetics are still a practical enough option. In fact, given how the quality of materials, methods of production, and basic construction technology have changed, it’s probably safe to say that has never been a better time for simple, but completely functional prosthetics.

Because let’s face it – as amazing as some of the latest bionics breakthroughs are, none of them is anywhere near close to being economically viable for most social classes. Of course, there are institutions such as Open Bionics that are actively changing this. But for the most part, the lower levels of society might as well be completely restricted from the wonders of current-generation bionic limbs.

Also, depending on the level of function that is still available with the damaged body part, bionic limbs may not really be a reasonable option at all. Again, Mr Ian Davis is a good example of this, proving that if the design is smart enough, the additional work/effort required for body-powered prosthetics is good enough. Perhaps the only thing that would turn this argument around is if the current research towards touch sense restoration becomes good enough for practical applications.

A Future Where You Don’t Have to Choose

Smartphones were first introduced in the early 1990s. However, this did not kickstart the smartphone revolution well until the 2010s because the technology simply wasn’t affordable enough to transcend societal limits.

We’d like to think that bionics, and prosthetics in general, are also treading the same path, despite still being in the early stages. To the average layperson, the difference between bionic and prosthetic simply lies in cost. If you can’t afford it, it might as well not exist and is kept as a science fiction dream within your sphere of influence. If you can afford it, then all the benefits of its latest research are right within your grasp. The lucky ones then get to be at the forefront of its development as willing test subjects.

Hopefully, as more and more innovations bring down the inherently huge costs of custom-made bionic limbs, generations after our own will welcome a future where that question isn’t even relevant anymore.

Featured image credit by This is Engineering via Flickr.