My research background is focused on using multi-material 3D printing, kind of based on the way the human body is. The human body itself is multi-material, and the impedance varies on each location, but the mechanical interfaces that connect our body usually don't vary much at all. It's this question of mass customization of devices that we interact with. If you go to the eyeglass store and you take an eyeglass frame, it is one impedance. It doesn't matter that your body and your face has difference impedances around your ear, you deal with it because this is what you have. Why worry? Why make a fuss about it?

The point is that we have technological advances today that you should be comfortable whenever you have an interface. So a knee brace should be made for you, it should be comfortable. Your ski boot should be comfortable. But more importantly, if you're an amputee—if you're somebody who does not have a limb—and you're using a prosthetic interface then your comfort and your livelihood are very intertwined.

Many people say that nearly 100 percent of amputees experience lots of pain within their prosthetic sockets. The reason is, because the way the socket is done is very crude, it's artisan. As an amputee I go to you, the prosthetist, and you take my limb and make a cast and have a positive mold of my limb, and you push on my limb and say, "How does that feel? Does that bone? This bone? And you say, "Yeah, yeah, that's very uncomfortable," and then you add material so that there's a void because the interface that you're going to wrap around my body is made out of carbon fiber, which is super hard, and it's going to have a lot of pressure on your body. So if your body changes, which everybody's does, then you have high pressures over places where you don't want those pressures. You end up having blisters, and pressure sores, and the amputee's livelihood is being impacted.

Here's an analogy, I suppose: If I gave you a pair of shoes that were $600, but they were maybe half size, two sizes, one size too small for you, you would not use it, right? You'd rather go barefoot. But if I give you a $10 pair of shoes that was comfortable—your size—you'll use that, right? So most amputees, especially those in the developing world, even though they're given free prostheses, choose not to wear the prosthetic device because it's uncomfortable.

What I'm trying to think about is: How do you capture the body's shape? How do you capture the body's impedance and have a predictive model such that you can use that digital data—which we can get from MRI and from a bunch of different digital scanning devices—and then build a robust model such that if I know that if I push on your body at that location in my model, with some force, the behavior of the model will be exactly what will happen in real life? Then, if you use those two sets of information, could you develop a multi-material interface to achieve pressures that will give you pressures optimized for comfort, such that you don't want high pressures over the parts of the body where you don't want them to be?

I think the biggest challenge to that really has been that the different stages in this process are led by different leaders in the industry. So to get good anatomical data, you need an MRI, and that's a different data set. Then, to do soft tissue modeling, you need a completely different software that's going to segment all your anatomy, and then you develop a model from that. To design a model of the interface, you need a completely different design tool. Then to manufacture it, these days, you can use a multi-material polyjet 3D printing. Those are very different tools that are being used, and the question is: Could we really be able to merge all of those such that we can achieve a level of communication between the different software tools so that it's easy for you anywhere in the world to walk into a medical facility, get imaged, and get a very comfortable interface 20 minutes, 30 minutes later, and you're out? So the next time you actually do go to get your eyeglass frames, you walk in, there's a scanner that goes all across your face, and I'm able to map—it could be an MRI—and I'm able to segment it automatically and it tells me exactly what your frame should look like, such that if you lay down somewhere there's not pain on your face, or there's not some scar on your nose. You can walk out with your eyeglass frame, for you, right there.

I think to answer this question, to be able to achieve this future, we need a lot of effort and a lot of multidisciplinary leaders coming together and deciding to say that it's time to work together to achieve this new interaction with machines for the comfort of the human race. 

Right now, if you go to Silicon Valley it's high risk, so people spend a lot of money for some product. In Boston, at MIT for example, where I'm based, it's not uncommon for people to think that technology will solve every problem. And when I go to Sierra Leone, where I come from, people in Sierra Leone are expecting either the government or some external actor to come and solve their problems. That external actor could be government, it could be an NGO, or it could be technology. But when you actually think about it, a lot of people say technology in itself is never good, right, that technology cannot be used to solve a problem. The question is: What are the set of things that you need to have in a culture, in any setting, such that if you bring a technology there, or better yet if they create their own technology, it can be used for prosperity, and it can be used for development, it can be used to create jobs, whatever it is that you want to think about?

Right now everybody talks about innovation challenges. The U.S. government spends a lot of money doing challenges, and actually a lot of the innovations that happen, like going to space, the satellites, weather, whatever it is, like the big picture problems were challenges that were opened out to the public. So the government does play a big role into that. At the end of the day you need the private sector to step in and make advances, but that doesn't necessarily happen in the place like Sierra Leone; those two, they are not connected right now. And so the challenges, by itself, needs a broader ecosystem, needs a broader support from the government, needs a broader support from rule of law you will argue a broader freedom to pursue what you want to do. Challenges are good, innovation competitions are great, but they are not enough.

Then you have another school of thought who say, "We need to create environments, we need to create spaces." For example, one the students I worked with—one of the young mentees I have from Sierra Leone—created his own batteries, his own generator, and an FM radio station to bring information to people in Sierra Leone. He's not very good at school anyway, but he's this great creative innovator who uses recycled parts from trash to make these products. It's easy to say, "Let's make a space for him, let's create a space," which is happening now because the government stepped in and they want to build a lab for him. Now, these environments that we are creating should not just be places where people make physical things. It should be about making the mind, because at the end of the day, a great battery does not have hands touching it; It's usually chemicals in, batteries out. But a great mind that can use garbage to create batteries is a mind that can make and bring prosperity and independence to a country.

So to focus on just a space is absolutely just the beginning, it's just the tip of the iceberg. There is a lot more that has to happen such that the people who go into those spaces—the young people who are there to make physical things—are also getting the transformational learning; it's creative thinking. They are being free to think about an idea and solve those ideas. And other people argue that it's about scaling products right there. So with the technology and solutions that we have today, we only need scale them, and we will solve the world's problems. Clearly, those people are within their own worlds, right, because there are so many other different platforms, there are so many other different resources that need to happen to be able to effectively scale a prototype solution, especially in communities like Sierra Leone.

So these are three examples of things that people can do and that people typically propose as a way of using technology to solve global problems, to bring prosperity. The people in these worlds usually super believe in what they want… It's about let's just make a space let's just do maker spaces and hackers paces and this is all we need to solve global problems. No. No. It's about the innovation challenges. No. No. It's about scaling these ideas and connecting all of these spaces, and whatever else. No. It's about taking Silicon Valley and moving it to Freetown. And these will always fail, they will always fail. I fear and worry that it will be this new age of technological colonization in some way, where it is not focused on the people who are creating the technology; it's not about the joy you get from making the thing. As an inventor, as an innovator, you think about the problem, you understand the problem, and you go through this process of coming up with a plan to solve such a problem. There's highs and there's lows, and there is collaborating—asking for help—and at the end of the day if you're successful after, I don't know, 20 failures, there's a joy for solving a specific problem. That whole process cannot just be shipped down from Boston to Freetown, it has to be experienced. You have to experience it once and then you experience it twice; you experience it three times and more to be successful innovators that are going to solve major problems within your country.

It's about thinking around and beyond our individual objectives, and goals, and areas of specialization to say the real way to move a country towards prosperity, not just one community, will be inclusive, will be broader than one specific area, will be bigger than government and private sector. These whole new public/private sector partnerships that exist have not really, in many ways, delivered what everybody thought that they would deliver. For me, I think, it's about focusing on the young people; It's about teaching; It's about making new minds; It's about teaching integrity and empathy; It's about having these young people go through these transformational changes that are required to make them innovators.

Almost every innovator I've met made something when they were young. To just assume that we can go to a community and say, "All right, you 30-year-old man or woman, who has not made anything in your life before, now you be an innovator," is almost callous. It's very naïve, because the skillset that we need as innovators, as entrepreneurs, are things that we've grown with, these processes. There's a way of doing. It's a way of daring yourself and other people around you to say, "I understand that problem. I don't know how to get there, but I am going to try and make this prototype. I'm going to try, and it's probably not going to work, but I'm going to learn something from it." It is making to learn and learning from making, which is something that is missing from the approaches that we've currently been exposed to, and that we want to just pick up and bring to poor or less economically developed countries.

I have worked with Neil Gershenfeld and the Fab Labs, and there is a value for that. There is the value to have digital fabrication and tools available such that anybody can make almost anything if you want to do it. If you have good processes to teach these new concepts to people it is a great initiative, and it's obviously produced good results in Kenya, the one in Soshanguve, in South Africa, and the other ones in Ghana. But like I said, a space is only important as the products that come out of it. It is not just about the physical things that can be made, but rather thinking about the products that you will make to solve a specific challenge in your community. I'm not saying that this is what they focus on. But to just make a product for myself, I don't know, I could make a new kind of comb, I could fabricate a comb such that I could brush my hair with it very well, it solves a very specific problem for myself.

To achieve the level of prosperity and development that we want, it's got to be beyond ourselves, and it's got to be looking into the community and solving very big challenges, and very big problems. That does not come from having tools available. The tools are essential when you can use them, but a bigger, bigger picture is the vision, and the mind, and the thinking that I know and I understand this problem, and I can speak to all these expats. I can go and collaborate, and ask the user of this solution that I'm going to have, this is the service that needs to be executed. There is a local material that I can access. It might not have to be electronics. It might not have to be technology, but it might just have to be putting sticks together, I don't know, tying those sticks together to do a very specific thing. It is that that we need to teach people in addition to having these spaces.

I think as you observed, it's not saying that the innovation prizes are not the way to go, because clearly they are useful. It's also not saying that having a digital lab, where you can make almost anything you want, is not the way to go, that is also absolutely necessary.

I'll tell you a story. I grew up in Sierra Leone. My three best friends and I studied together through our high school exams and we got the best results in the country. I left, went to the U.S. for college. They went to college in Sierra Leone. One of them did civil engineering, the other one did mechanical engineering, the other one did electrical engineering. They got the best results in their department, hands down, they were one, two, three in the whole university. And they all ended up going to get master's degrees as well. One of them now has a master's degree in mining engineering, the other one in civil engineering, the other one in electrical engineering, from international institutions. We'll meet and hang out for drinks. We can talk about Sierra Leone's problems all day. The problems are there, absolutely, in your face, and we can complain about governments, but the minute I say, "All right. So, here's what we're going to do. How do we solve this problem?" Here we have some of the smartest engineers in Sierra Leone, very highly academically qualified. Isn't the obvious thing that we come together to solve some of these problems? Let's have a problem-solving session; let's just think about solutions. The conversation dies, it's really sad. Because, you see, they're smart people, and they're my best friends, but we cannot think about solutions at all, but rather the conversation ends by somebody saying, "Oh. The government will do it. The government should be doing it. Why is the government not solving the problem? It's why they're there." Or say, "David, I think it's because you went abroad. That's why you're thinking this way." It's really sad to see that.

Well, I guess it's obvious that high academics is not necessarily equal to, "I want to be an innovator, I want to solve," which brings us back to my original point that we need people to learn the process. You do not just say here's a competition, here's a set of tools that you can use, but we need to actively guide young people to be problem-solvers, otherwise, we'll continue to have all these smart PhD people who don't know how to solve any problems.

To be honest, all the ministers in Sierra Leone, probably all of them have PhDs, and many of them probably went abroad to study for these. Sierra Leone is a wealthy country. We have almost any mineral you want. We have maybe the third largest deposit of iron ore, or something, that gets shipped to China on a daily basis. We have diamond, which led to the problems with our war; We have gold; We have water; We have arable land; We have smart, intelligent people that all have PhDs, but what do we make? It's almost sad to think that you can have all of these different elements. You have the water; You have the sun; You have the land; You have the minerals; And what we don't have is the minds to put all of those things together, I'm sorry to say. It's different from being academically smart, but we are not putting those things together. And how do you do that? I don't know.

I think the cost of 3D printers is going down. We will see a lot more multi-material 3D printing. The cost of MRI will probably go down. There will be new image and technologies. There's somebody in my research group who is making a tool that can measure the impedance of your body and capture shape at the same time, absolutely cheap. You have a force and displacement sensor, and you have all these models, and you are checking the location. You can be able to measure the impedance at each location, because it's really all what you want. When I do a segmentation of your body, and I try to understand where all the muscles are, and where all the bones are, and where the fat and skin is, and I build up a model, what I really want to know, the one simple thing is what's the impedance of that location. And if I can build a machine that just gives me an impedance and shape, then I'm done with it. I don't need an expensive MRI, right? So that's where innovation comes in.

Once I'm able to get shape and impedance of this location accurately, then I can use that information to develop an interface using very free open software, in which you can do CAD, and then you can create a mold, if you want. You can create a mold from the $1,000 3D printer, and then figure out ways in which you can cast multi-material products that you want to have.

But I think it's absolutely important for amputees to be able to be comfortable. I mean we live in an age where we have flying cars, and self-driving cars, but then an amputee cannot be comfortable; they cannot wear a prosthetic socket that's not going to give them blisters and bruises. If they go running for one day, they have to not maybe run the next day, because they are in pain. It's absurd to think about it.

Here's actually a much bigger problem: A human body, as we know it is a system. What I do with my hand, my whole body knows what's going on when I do that; there's a central control and it knows. Today, we have a lot of bionics in our bodies: The pacemaker, artificial hearts, we have FDA-approved bionic eyes, we have FDA-approved bionic ankles, which my professor uses, we have bionic knees. If something goes wrong with the bionic knee, the bionic ankle doesn't know, certainly, my whole body doesn't know. The people who are the architects of the bionic ankle have no idea what's going on with the bionic knee, or most certainly do not even know about FDA-approved bionic eye and what architecture they used to create it.

Our human body is coded by DNA. I think the bigger question for us and the people who are developing bionic technology is: Are we going to move towards a place where the bionics in our body all can communicate? Or better yet, if we do not want a whole entire system to communicate, could we have, like a body area network, nodes, such that the behavior of your bionic ankle and the behavior of your bionic knee are very well in sync with each other? The impedance, the torque that you're getting at the ankle should be determined by what's going on with your knee, right, and vice-versa.

So what does that look like when all of our bionic elements are talking? And at the bigger level, what does that look like when they can talk to our body and to our brains? For a unilateral amputee, they have a biological ankle, they have a bionic ankle. Wouldn't it be crazy to think about an architecture where what I'm thinking is not only controlling my biological ankle, but I can also control my bionic ankle? And with the FDA-approved bionic eye, the inputs that you're getting are controlling not just your biological function, but also any other bionic element that's in your body. The artificial pancreas can talk to, I don't know, some other bionic element in your body that's necessary, if you have a kidney transplant, if you have an artificial 3D printed kidney, which we have seen. There are 3D printed blood vessels that are there.

If you put a biobot in there, could you have it such that the biobot, when it does exist, it's trimming your blood stream, it's flowing in there, could correspond with your artificial bionic pancreas, if sugar levels are high or low, and be able to activate that? This is way forward thinking that has to start happening now, right?

But it's really exciting. I mean part of actually the reason why I got into all of this, trying to understand how you can map bionics and have the bionics communicate with each other. It has its challenges, and we'll talk about that soon, in that security, for example. But once you can have all of these bionics, you can think, I don't know, in the future. I play football, and I was hurt, and I was limping one day, and my friend is like—my friend knows that I develop prosthesis—and he's like, "You should just make yourself a leg." And I was like, "Actually, it's not that funny, because if my legs were bionic, and I could control them, or I could tune them, then I wouldn't be breaking them all the time." But the reason I won't do that right now is because I know the prosthetics sockets suck, which is what I'm working on.

And there will be a point in time, I don't know, when I'm older, when I want to achieve something else, where I will choose to get bionic parts in my body. Other people don't choose right now. They're given artificial hearts. They're given a bionic eye. But to reach the point where we can choose to augment our body, which means we have to redefine what it means to be human, and we have to redefine what it means to be disabled. We have to define what disease and illness means. These are all questions that are very open, that the advances in technology will force us to have. But I think we should have them now, as we're doing the developing.

So, there have been improvements in the exoskeletons, right, so, actually, some people in my group have been doing research, and how do you have running exoskeletons. But, again, it brings us to my point, original point. The biggest problems with exoskeletons is how you attach them to the body. They're not comfortable. The body is optimized to reduce metabolic cost when you do a certain function. And adding mass to the body requires energy, and if you are going to change the way you walk because something's attached to your body requires a lot more energy, and that counts as the effect of the exoskeleton, which is supposed to make you do something better. I mean you have regular normal function, and you want to optimize your function. The question of attaching the body to machines comfortably actually is a very fundamental one to the advances that we will make in technology. But I think we're not that far away at all. I think it's happening more and more where people choose to have bionic units added to our system. Cochlear implants, in the past, it maybe used to be strange to have people have ear implants. That's standard today, that it's bionic, given its mechanical made thing that is supposed to be mimicking, if not, at some point, giving us a much better function than our biological units provide today. I think once we reach that point that we can safely put bionics into our bodies to achieve equal or better than what our regular biological parts do, then this conversation about having all of them be connected will become relevant, right?

What I fear, and I'm not sure about how much money it will cost to, after we have developed all of these areas differently, in different silos, and we are at the point being like, "Oh, shoot, we've got to come back all this way to be able to have them be connected." A friend of mine was telling me recently the problem of standardization is you want to make advances in the different areas before we can standardize across, right, so you want to have long Ts before you can go further, in some ways, but you never know which point, like, will it be limiting.

With regard to the security question I had raised. I think somebody you can control in the past, you can control people's hearts—their pacemakers—which is absolutely terrible to think about my pacemaker being controlled by somebody else, but then as we talk about different bionics communicating with each other, as we talk about my bionic knee communicating with my bionic ankle, if I have an artificial hip communicating, it has some sense of communicating with my ankle, information is being transmitted, and there can be an interference, and somebody could have access to that information that is not you. And so then the big question then becomes, which is a completely new area of research that will happen because of this, is what is the security of body area networks of bionics? What's the information packets that need to be sent, that's transmitted between different bionics to achieve a very stable security source that I know that, as an amputee, somebody's not going to control my knee and ankle to make me move involuntarily and hurt me. And what does that look like if somebody can communicate with my pancreas? Or my kidney? If I'm getting information to that.

I'm from Sierra Leone, and I remember vividly … and actually, it ties both of my big questions together. I remember when I left Sierra Leone, and I went to Norway for two years, and I attended a Red Cross Nordic United World College, which is a high school that brings together 100, 200 young people from all over the world to go to school for international understanding and world peace. There are 12 of them around the world. I had learned that I got into Harvard. What did I do the very first day that I got into Harvard was I searched for technology entrepreneurship Harvard, and it so happened that there was a center called Technology and Entrepreneurship Center at Harvard and this professor, this lecturer, who became my very, very good friend and mentor, Paul Bottino, whose name, and Email, and phone number were there. So I picked up and called, and I said, "Hey, can I speak to Paul, please?" And he said, "Paul speaking," and we ended up speaking for 40 minutes. And the topic of that conversation was an observation I had made.

A lot of amputees in Sierra Leone were sitting on the street begging. And then I went to my dad's office. My dad works for UNICEF, and we're hanging out with his friends, and then I said, "Why are all the amputees on the street begging? Don't they have free prosthesis?" And somebody in the audience said, "Well, obviously, they all like to beg. I mean they give them free products, and they go and sit by the street, because they don't want to do anything for themselves." And this was not a satisfying answer, but it was also very disheartening to hear that this was what they thought about amputees. So I went to this camp, just in Freetown, and I met with the director of the center where they were making the prosthetic devices, and I went and saw the tools that they used to make the prostheses, and I spoke with a bunch of amputees. And it became very clear that the reason why they don't use their prosthesis was because it was uncomfortable. It was free, but it was uncomfortable, and gave them pressure sores and blisters. And obviously, nobody in their right senses will use such a prosthesis.

There are two problems here: One, they're uncomfortable and cannot have a normal life, even though the product has been given to them for free. There are these people who are leading the country, who think yes, I mean we give them for free, they should be able to use it. They're not trying to help themselves. The science of improving how you connect the body to machines needs to be improved, and it does not only need to be improved in Boston, it needs to be improved globally.

It so turns out that connecting the body to machines is still crude, whether you're in Boston, or Bombay, or Freetown, so that's a global problem, and it was an obvious one to try to start solving and thinking about. There's a bigger picture of why these people, who are highly academic, are clearly not solving the problems that are leading to the challenges that's keeping this amputee in the street. They do not understand those problems. All they talk about is PhDs and what's in the news, and books, and education, and learning these formulas, hence the conversation that I have with them is "David, how is school? David, how is your PhD? How's your master's?"

Clearly, the reason why this person, this amputee, who is not doing anything with their life, is still sitting down on the street begging is because probably they did not make something when they're young. They are not entrepreneurial enough. They are not using the technology that's readily available to them, to take advantage of the opportunities that are so readily available to them as well, to lead prosperous lives. I love making, I love solving these problems. I think beyond me, beyond our individual silos. To achieve prosperity and development in a place like Sierra Leone does not involve giving free devices to victims, which leads to low self-efficacy and dependence on external actors; we need to make new minds. That involves giving young people the platform to innovate, to learn from making, and to learn, and to solve very tangible problems within their communities.

So it seems like those two things were connected. And I still don't know how to solve them at all, I mean it's not like I know how to solve this idea of connecting the body to machines. That's why I'm doing the PhD, and at the end of it I will know how to do it, but it's very relevant. And then for myself, selfishly, I just like to think about what will happen when I'm old and I need bionic units. I want all my bionics to be talking to my body so I can be Superman.

My professor is a double amputee, and I work with him very closely, and the products I design he tests out. He actually uses some of my products. And it's wonderful to see him describe a product I make as "It's like walking on pillows." It's great, especially when you know that, globally, amputees are in a lot of pain, and we ourselves don't know how to comfortably connect our bodies to machines in a repeatable way.

As we solve those problems, what does it mean to say I want to see a prosperous Sierra Leone? What is the nervous system of a country like Sierra Leone that has a lot of the resources necessary for development, for economy development, for job creation, for lowering poverty, any of these things that they use at the UN as jargons. What does it mean to enable the generation that can solve those problems and move towards actual global development, and avoid all the rhetoric that goes on with Vision 2025 or Vision 2030?