The Future of 3D Printing Assistive Devices

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ROMA AGRAWAL

3D printing is one of the most exciting new technologies to emerge in the last 30 years. And its arrival promised a revolution in our everyday lives. Every home will soon have a 3D printer. We'll all be engineers, manufacturing for the people!

Well, it didn't quite happen like that. 3D printer sales didn't go through the roof. But 3D printing is revolutionising everyday life for a large group of people.

ENZO ROMERO

People like ourselves, I'm wearing a prosthesis, you guys are wearing a pair of glasses, and we are wearing assistive technology every day in every activity. So everyone eventually is going to need an assistive technology device.

You're listening to Create the Future, and in this episode, we're going to explore why 3D printing is a game changer for assistive technology for disabled people.

WILLY ALLÈGRE

Only 1 in 10 people who need assistive devices worldwide currently have access to them. 3D printing is a very significant tool that can help solve by enabling affordable small-scale production of personalised devices.

ENZO ROMERO

it is quicker, it is not as expensive and you get to create complex geometries around it.

ROMA AGRAWAL

I'll be chatting to Willy Allègre, the founder of the Rehab Lab Network, which empowers disabled people to design and 3D print their own assistive devices, and Enzo Romero, an inventor, engineer, and researcher who's developing affordable, personalised, 3D printed prosthesis.

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ROMA AGRAWAL

Thank you so much for being here, Enzo and Willy. It's such a joy to have both of you. So, Enzo, could I ask you to just introduce yourself for our listeners, please?

ENZO ROMERO

My name is Enzo Romero. I am a mechatronics engineer here in Peru. I was formed at the Pontifical Catholic University of Peru. I work here too at the Biomechanics and Applied Robotics Laboratory. And also, I'm the founder of an organisation called LatBionics, where we develop upper limb prosthesis for people of low income in my country and across the region.

ROMA AGRAWAL

Fantastic. And Willy, could you tell us about yourself, please?

WILLY ALLÈGRE

My name is Willy Allègre. I'm an engineer working in France with a PhD. And I work in both a rehabilitation centre and in an innovation centre. So on one hand, I'm the head of the Assistive Technology Lab of Kerpape Rehabilitation Center in the West part of France, Brittany region. I'm working on assistive technologies, so considering IT accessibility, augmentative and alternative communication with speech synthesis for people who can't speak, like I do right now. And for example, home automation to adapt living environments for various disabilities .

ROMA AGRAWAL

Willy, what inspired you to get into this area of engineering?

WILLY ALLÈGRE

I was first an intern in the Kerpape Rehabilitation Center. It helped me a lot to see that disability can be a field of application of my technical skills I learned at school. Just after this, I decided to develop one PhD thesis on software, so on home automation software design for occupational therapists. And then I worked as an engineer in this rehab centre.

ROMA AGRAWAL

And Enzo, I understand that you had a slightly more Hollywood inspiration into this world.

ENZO ROMERO

Indeed, indeed. At the beginning, it wasn't about engineering at all. It was, you guys have watched Star Wars number five, where Luke's hand gets cut off? Well, that was my situation. I was born without my right hand. Watching that movie as a kid, watching the main character of the movie, then after his hand gets cut off, being replaced by a hand by the robotic droids, and not only a hand that could move and feel, because when they pinch it, he has some reflex moves… that moment changed my mind. From that instant, I never wanted more a prosthesis like Lucas Skywalker. And I didn't even know that I was going to make it or going to buy it. But that idea kept on my mind from when I was seven years old. So that led me eventually when I was 16 to study mechatronics engineering, just to develop a prosthesis for myself.

ROMA AGRAWAL

I love that story. Willy and Enzo, before we get into the details of both of your work and specifics, I want to understand a little bit more about the world of assistive technology. My first question is, why is 3D printing in particular such a key innovation? Enzo, you sort of showed me your right hand. Could you tell me a little bit about how 3D printing is involved in this?

ENZO ROMERO

Yes, of course, of course. So right now I'm wearing one of our body powered prostheses. Since the level of my amputation is over my wrist on my right hand, I could move a little bit my wrist and the prosthesis will activate. When I do some flexion, all of the fingers will close, and when I do some extension, all of the fingers will open again. 3D printing helps us in this way because no matter the complexity of the amputation of the user, we can create a prosthesis socket, and we can adapt the size of the fingers, the size of the palm, and adequate the prosthesis socket regarding if, for example, the accident just passed like three months ago, or have passed 20 years ago, we take all of those points in order to create a personalised prosthesis. That is one way to look at it. But then when you are going to produce a prosthesis, traditional methods of producing an upper limb prosthesis will tend to lead to two to three months of production process because you need to cast it, then to produce a matrix, and then eventually elaborate on all of the parts. With 3D printing, we create a design, and in just two to three days, we have already printed all of those pieces. And right now, the cost of materials that are biocompatible like PLA on orders, they are not as expensive as it used to be like 10 years ago. So it is quicker, it is not as expensive and you get to create complex geometries around it. So it helps nations like mine to have the most quantity of prothesis for people of low income.

WILLY ALLÈGRE

At the global level, 3D printing provides a way to create custom-made assistive devices, not only prostheses, but also more general objects that enhance disability situations. Disability often requires tailored solutions for small groups of people, which makes traditional production methods costly and also unattractive to large companies. This is a global overview of the situation. According to the World Health Organization, over one billion people live with a disability worldwide. And by 2030, it will be more than two billion people. We will need at least one assistive product, one assistive device. Also, only one in 10 people who need assistive devices worldwide currently have access to them. So 3D printing is a very significant tool that can help solve by enabling, like Enzo said, affordable small scale production of personalised devices. So 3D printing empowers individuals directly. I think probably Enzo’s story is the best way to give an example, but I can also give other examples for assistive devices generally.

ROMA AGRAWAL

So it sounds like 3D printing really helps in terms of customization, inspiring people, I guess, to get something that really actually fits and works for them. And then also the idea that mass manufacture doesn't really work. That makes a lot of sense. So I'd like to now speak to each of you and learn a bit more detail about your work. So if I start with you, Willy, on the assistive devices. So could you give me a few examples of the sort of things that you're creating and that people are using?

WILLY ALLÈGRE

To give a concrete example, one of our first patients or users from our rehab centre, Jean Christophe, who is tetraplegic and also a DJ. So he only can move his head. And so the challenge was to work with him to install and configure head tracking so he can use his head to control his personal computer. So that was the first step for us. With occupational therapists of course. But Jean Christophe wanted also as a DJ to control his physical mix table. So he proposed himself, back in 2016, to design his own custom button switches so that he controls with a mouse stick to mix music autonomously. This example is a very extreme one of how 3D printing can enhance disability situations and empower people with a high level of disability. Maybe I can give another example, a more classic one. Another user co-designed a glass holder. A very simple object that allows him to drink independently, using his right arm despite his tetraplegia also. This story shows the impact of co-creation because this person was able to choose the colour, the shape, the design of his own glass holder. So yes, this is just two examples out of hundreds and thousands of objects available on web platforms today.

ROMA AGRAWAL

And you said this incredible kind of mind blowing statistic that 40% of assistive devices are abandoned during the first year. So what is happening there?

WILLY ALLÈGRE

Yes, you're right. 30 to 40% of assistive devices worldwide are abandoned one year after their first use. We can work on specific actions. The first one is to consider how to reuse those assistive devices that are abandoned. But we also think that involving users in the design process can enhance the usability of the device in the long term.

ROMA AGRAWAL

Enzo do you see a similar sort of statistic in prosthetics about people abandoning their prosthetics quite quickly?

ENZO ROMERO

Totally, totally. Yeah. We have here something called the belonging sensation, which is when your expectation levels were so high because you were going to have a prosthesis, that the fingers would move independently, and the look of the prosthesis would be the same as your other hand. That's more common in users that have come to us because of an accidental reason, a traumatic reason. In those that comes from a congenital origin, it doesn't matter that much. But when it's because of an accident, they wanted the prosthesis to look exactly like their other hand, and because the expectations levels are so high, when they are fitted a prosthesis, even the most advanced of all, that it is not going to be enough. So after one year or two years, they are not using the prosthesis at all. So in order to try to avoid that situation, we're trying to develop an aspect like Willy has been doing in his organisation, which is to collaborate with the user into the design and implementation of their prosthesis. That is fundamental. Does he want to have a prosthesis just to look like a human hand or does he want to use it as a tool in order to get back to work? And if it's at work, if it's a robust prosthesis or if it's for more delicate operations. So that is very, important. In Peru or in the region, according to UNOPS, four out of five people with upper limb amputation lives in developing countries. And here, one of the main problematics is that you have don’t companies that are formal. And if they are not formal, they're not going to give you an insurance to afford most of the basic prosthesis that you can handle, like a hook type prosthesis or a static hand. And if you want to buy it for yourself, here in Peru, a robotic prosthesis hand could cost around $25,000. So the people that tend to suffer from an accident in my country is because we are working in metal mechanics, agriculture, or even manufacturing. Accidents are on the tip of the hand, right? So you're going to expend at least seven years of savings just to buy a robotic prosthesis. So that is not a situation that we can handle anymore in the region.

ROMA AGRAWAL

Absolutely. I'm going to come back to you as well. I want to know, maybe I'll start with you, Willy. Can you describe to me what happens if somebody comes to you or into one of your labs and says, I need XYZ? What's that journey like for them?

WILLY ALLÈGRE

So maybe I can talk about the Rehab Lab project I put in place in 2016. So the basic idea behind it was to create a dedicated space for patients with digital fabrication tools, one computer, one 3D printer, and so to let them build by themselves their own assistive devices. They are helped by an occupational therapist and also a technical referent, engineers, but a lot of different people can access this role. And then the patient can start from scratch with the ID. Talk with healthcare professional about the project. They talked about technical specification, functional specification, and then he can design by a CAD tool their own object. Of course, it is an iterative process because once you have the first version, you print it, so you test, you evaluate it with a healthcare professional, and then this is it. Now we have launched what we call the Rehab Lab Community. So it is a network of health care organisations through Europe, but it is also worldwide right now, to let each patient from rehab centres and hospitals do the same, so create their own assistive devices.

ROMA AGRAWAL

You've gone from 1 lab to 61 across Europe in just eight years?

WILLY ALLÈGRE

That's it from 2016.

ENZO ROMERO

That's amazing.

ROMA AGRAWAL

I mean, that's absolutely incredible. And I mean, I want to know a little bit about how you feel, but also what does the person feel like? What is the kind of thing you see when they first see their creation in their hands?

WILLY ALLÈGRE

There are lot of different kind of reactions. So it is like magic for some people. We were very surprised about seeing aging people, aging patients doing the whole process, meaning learn how to design and it was very impressive both for them but also for people who helped to do it. This is the first reaction, like a bit magic, but rapidly when you consider 3D printing as a tool, you imagine other devices you can create for yourself, but also for other patients. So that’s the part we are working on right now on pair emulation so people from the rehab centre can help other patients to design assistive devices.

ENZO ROMERO

That's so great.

ROMA AGRAWAL

Enzo can you tell us about when you first designed and received a prosthesis and how that felt to you because you've got a very personal story with this.

ENZO ROMERO

Yes indeed. So I was working already at my lab here in Lima and we have recently won a national fund in order to develop this project, which was to develop a prosthesis that could have a motor into each finger. So it could have more than one degree of freedom and two degrees of freedom on the thumb. And it was this multidisciplinary team, around 10 to 12 people, not only mechatronics engineers, but biomedicals engineers, electronics, occupational therapists, industrial designers, psychologists. Because when you're working with these types of devices, assistive devices, it doesn't matter only just the mechanisms or the electronics behind it, but how is the user going to feel about your prosthesis, right? So eventually I was the pilot user of this prosthesis back in 2016 here in Peru, we have already developed the very first prothesis that was both designed and developed in the country, having the necessities of our people in mind. And I was a pilot user. I was able to move each finger individually. We have an arrangement of electromyographic sensors on my forearm. And that instant, like pursuing this dream from when I was seven years old, has been magic. Yeah. I couldn't describe it more. That has been the work. Having that in mind, this sensation of magic just comes to you like for a period of time, and then you try to iterate, like, what could we do next? How can we improve this? And how can we take more advantage of the 3D printing? For example, if a piece has been made with 70% infill, it's heavy. So what about if we turn down that level of percentage? What is going to happen if we turn it down to 50? And let's try again, and again, and again. So that has been the more wonderful part. Like, as a maker, try to iterate in order to enhance your creation.

ROMA AGRAWAL

I love the idea of the iterations that you're talking about and one of that is to do with haptics. So can you explain what haptics is and how you've started to incorporate that into the designs?

ENZO ROMERO

That is one of my main research areas because once you have already lost your hand, of course you have lost the sense of touch, of grabbing things, but no one realised that you also have lost the sense of biosensing like getting to feel when an object is hot or cold, or if you want to put your finger on a needle and feel that pain, that instant pain, if you're wearing a prosthesis and you're touching things and it's hot or cold, you're not going to realise it. So what we are trying to incorporate into our prosthesis is these haptic feedback systems in which we incorporate sensors in the fingertips of the prosthesis and the thumb. So when you have put pressure on a surface or an object, you will feel like a vibration or a small pinch that will be directly related to the type of force you are pressuring into an object. And that helps the users. And we tend to think that this belonging sensation that I was speaking at the beginning increases when you think that this prosthesis is not only just to grab things, but it makes you feel things about the objects that you're grabbing.

ROMA AGRAWAL

I love this idea of design because you've got somebody who requires some sort of assistance in some way. They're not necessarily designers, but then you're coming in and saying to them, let's design this thing together. So, Enzo do you have examples that you could share with us of how, you know, any individuals or any stories have stuck with you of somebody coming in, designing something, receiving it and what the impact has been on their life?

ENZO ROMERO

Of course. So for example, we have this user. His name is Gonzalo. Gonzalo lost his hand like 20 years ago. He possesses a transradial amputation between the wrist and the elbow. And he's an informal worker, he sells like chocolates and candy on a market here in Peru. And he hadn’t enough money to buy a prosthesis for himself, 20 years ago, there was no solution. So we work with Gonzalo. We produce one of our personalised prosthesis, a body powered prosthesis, so he needs just to move his elbow and the fingers will close, and when he release his elbow, the fingers will open. And we developed a prosthesis that was made for him. And right now he has increased his production because someone at the market hired him because now he has a prosthesis. And that look of compassion that people have when you are a person with a disability tends to make them believe that because you don't have a hand, you're not helpful at all in any kind of activity. And of course he was capable of doing it without one of our prosthesis, but having this sensation of, he's wearing a prosthesis, that feeling of compassion changes to something of amaze or “What is he wearing? How it works?”, and they have hired him. So now he's working on a more formal level and as a consequence of wearing a prosthesis. So yeah, that is one of our biggest stories here, Roma.

ROMA AGRAWAL

Just as you were talking about that, I was wondering, Willy what message would you like to give our listeners in the way they view disabled people?

WILLY ALLÈGRE

So first of all, engineers have to consider disability as an aspiring field for innovation. Some of the most widely used technologies were first developed for people with disabilities. For example, the remote control was originally designed for people with limited mobility and today it's a standard device for everyone. And also I'd like to say that similarly in 2024, the Paris Olympic Games have shown that sports can empower people with disabilities, but also inspire everyone. The same is true for assistive technologies. They have the potential to inspire engineers across all fields, industrial fields also, by demonstrating the power of involving end users through the development process. I think iterative process with end users in the loop in each step of the process is something very specific to disability but should be a standard for each engineer in the world.

ENZO ROMERO

Totally. What Willy just said, I think, is powerful. Because I already felt that look of compassion. I was born in Cusco, which is a region, not the capital here in Peru. And back then I lived in a little town called Urubamba. And in Urubamba, like around 12,000 people, they already knew my family, they already knew me. So when I was a kid, I had no problem at all, not having a prosthesis and developing all of my activities, like playing basketball or having fun with my friends. It is when I moved to Lima to study in my career that I got that feeling of people staring at you. It is the stare that kind of annoys you because once you realise they have been staring, they tend to look to the other side. And you already have that compassion decision. What happened to you? I'm so sorry. Because they tend to believe that you are not good enough. And we try to use our prosthesis like not just a tool that will help one of our users to get back to their activities, but as a movement in which assistive technology helps you to develop this and helps you to realise that there are people like ourselves, I'm wearing a prosthesis, you guys are wearing a pair of glasses, and we are wearing assistive technology every day in every activity. So. Everyone eventually is going to need an assistive technology device.

ROMA AGRAWAL

So what could we do better in the future, Willy? What's your vision for the future of engineering for disabled people?

WILLY ALLÈGRE

Maybe on 3D printing. It will continue to evolve, of course, with more advanced materials like carbon. We already work on carbon materials with 3D printing silicone. So it will become widely accessible also. It is already right now. But beyond the technical improvements, I believe that open innovation will play a key role. The ability to share and reproduce designs through open source… Open platforms can foster collaboration and help create sustainable, socially responsible solutions also.

ENZO ROMERO

All of us have already have a printer, like a paper printer in our homes because it was so widely available and it was not as expensive at all. I would like to have that with 3D printing machines. Having a small 3D printing machine in your home to help you to develop your very own assistive technology products in whatever you want. Like you want to hold your cell phone in this way, okay, develop it. And being in touch with this community of open source devices and models that are widely available on the internet that we engineers tend to take advantage of, but not all of the people around the world tend to. And I think having that in mind, like how can we teach that in schools that you don't need to have an engineer’s degree or be mathematical oriented to developing, because right now the softwares that are into design are so intuitive. Like when people tend to think that we are into coding, not at all. Like you have a graphical interface, you get to move all of the parts of your design in whatever way you want it. You get to produce it at your home in just two to three hours. That will be mind blowing. And about LAT bionics, I would like us to become a regional beacon of assistive technology generation. So far we're into upper limb prosthesis, right? But I would like to have, like a 24 floor building, in which on each floor you get to produce an assistive technology regarding your limbs, your downward limbs, your upper limbs, about your speaking, your thinking. And even if you come as a user, there is going to be a whole team that is in an holistic vision would help you with graduate students from universities that are developing their thesis in pre-undergrade or post-grade. You have medical doctors, physiologists, industrial designers. So no matter what your complexity of your disability, then you're going to have an assistive device that is personalized made to you. And that idea of Willy of co-creation, totally mind blowing.

This has been a great opportunity. It is not common for me to have these type of conversations because in the region, of course, we were trying to have this generation of prosthesis and in each country at least there one like me, like a guy in Argentina, a guy in Bolivia. I want it to be more a community like you guys have in Europe in that you're in UK, you're in France, you're in contact and you get to produce. I want that feeling for our region too. And one idea that I'm taking from Willy, it is develop this big chain of how to give someone a favour. It has been one of the greatest ideas that I received today and I want to apply it.

ROMA AGRAWAL

This is brilliant. It sounds like we have the start of a global network for assistive technology starting today.

WILLY

Yes!

ENZO.

Totally!

ROMA

Thank you so much.

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It's been really inspiring for me and very refreshing to have this conversation with two engineers that really and truly put the users into the centre of their designs, get them involved and then I guess see the magic that happens when their creations come to life.

And speaking of innovators in 3D printing, the Queen Elizabeth Prize for Engineering hosts a 3D printed trophy design competition open to young people aged 14 to 24. And I'm one of the judges of that competition. The winner receives a laptop, a model of their trophy and the opportunity to see their design presented to the winners at the awards ceremony in London. Be quick, the 2025 design competition closes on 29th November this year. So if you or a young person you know would like to have a go, follow the link in the description of this episode.

You've been listening to Create the Future, a podcast from the Queen Elizabeth Prize for Engineering and Peanut and Crumb. This episode was presented by me, Roma Agrawal, and featured Willy Allègre and Enzo Romero. It was produced by Rose-Anna Hyde. To find out more, follow QEPrize on X, Instagram, and Facebook.

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