3D printing is being used for all kinds of wonderful things in the medical industry. From 4D printed artificial muscles to 3D printed heart models, to tissues with blood vessels to low-cost prosthetic parts, 3D printing is opening up a whole new way for people to advance their fields and offer to patients genuinely useful alternatives to traditional medicine.
So when UK start-up Open Bionics won the James Dyson Award for their prototype 3D-printed robotic hand back in August, the world took notice.
Their prototype made waves for three key reasons:
1) It can be built for less than £1,000, versus the tens of thousands of pounds it costs to build a traditional robotic hand
2) Whereas it usually takes weeks to obtain just the parts needed to build a robotic hand, Open Bionics’ robotic hand can be made in less than two days, and
3) All designs are open source, so anybody can download and print their own hands.
And now, Open Bionics is going even further.
On October 7th, Open Bionics unveiled their latest range of robotic prosthetics offering the very same functionality as the original hand. But the key difference is this – the new prosthetic hands are child-sized, thus creating a new prosthetic solution for child amputees.

The 3D printer behind these new prosthetics is the Ultimaker 2 Extended, a seriously impressive 3D printer that’s speedy and reliable with a 20-micron definition and a 230 x 225 x 305mm build volume. The materials of choice are NinjaFlex (an ultra-flexible filament, patent pending) and your bog standard PLA. Together, these materials create the perfect blend of flexibility and strength that a prosthetic limb needs.
So how do they work?
The robotic hands have a network of internal strings that can be thought of as tendons. These strings are activated by myoelectric sensors attached to the forearm muscles to open, close and grip just like a living hand. Where 3D printing comes into play is actually making the parts of the hand – so the fingers, palm, wrist and arm are all 3D printed parts.
The parts themselves feel artificial. But hopefully, filaments will be released in the future that mimic the look and feel of human skin – we’ve already got filaments that replicate the look and feel of metals, such as BrassFill, so why not something organic?
Do they work?
It’s all well and good explaining how these limbs work, but do they work in the real world?
The short answer is yes, they do. Back in October 2014, Open Bionics performed a world’s first by fitting a person born without a hand with a 3D printed and 3D scanned robotic hand. It’s important for us to note that although 3D printing a prosthetic socket had been done before, this was the first time a 3D printer had been used to custom fit such a device.
In the end it came out incredibly well, and the patient was left gobsmacked.
The great thing about these prosthetics is that they can be custom made to the wearer so they feel – as far as is reasonably possible – like a natural extension of the body. Open Bionics is a business, and so while their designs are open source and anybody can print their hands in their own home, they’d rather you came to them for a custom job, which makes sense if you are indeed an amputee as this will ensure the best possible performance.
In addition, Open Bionics believes that while all prosthetics should be functional, they should be stylish too and that’s why their prototype was highly functional without looking like Bicentennial Man’s hand. And that’s the reason behind these new prosthetics being modelled after superheroes, and Disney’s Frozen.
The technology isn’t perfect just yet, but it’s being worked on
One thing that was strikingly obvious back in August when Open Bionics won the James Dyson Award for their prototype was that their prosthetics aren’t quite there yet in terms of offering the mobility that a real, living hand offers.
For instance, while you can pinch things, pick things up and do basic tasks like hold a mobile phone or a glass of water with one of these robotic hands, you can’t do more intricate things like tie your shoelaces or feed some thread through a needle. It’s this ability to perform intricate tasks that will really change an amputees way of life. We’ll give them the benefit of the doubt though, bearing in mind they’ve only really just started to ramp up development and research deeper into the world of myoelectric-controlled prosthesis.
Plus, Open Bionics say that they are working on that, and their launch of a new range of robotic prosthetics for children – which look absolutely fantastic – shows some significant progress on that front. All of which is to say there’s exciting times ahead for robotics fans, and the Ultimaker 2 Extended is proving to be an excellent 3D printer for medicine – we wonder what this 3D printer will be used for next?
Source: Open Bionics