Startups solve real problems.

During the boom times, the media focuses on the multi-billion-dollar valuations and the mega-IPOs. But even in those times, founders are innovating in the background and using technology to just make the world a better place.

Today we talk with Sun Xiaojun, who started BionicM in 2015 as a way to replace the limb that he lost when he was a child.  And since then, he has built the startup into much more.

We talk about the challenges he had to overcome to bring innovative medical technology to market, why Japanese universities still struggle to productize their impressive deep-tech,  and why the world has been thinking about prosthetic limbs all wrong for thousands of years.

It’s a great conversation, and I think you’ll enjoy it.

Show Notes

  • Why powered prosthetics are a game-changer
  • The challenges of being your own first beta-tester
  • How coming to Japan changed Sunny’s life
  • How prosthetics are fitted and sold
  • Go to market strategy and discovering the true customer
  • Total addressable market size
  • User feedback, human variation,  and future changes
  • How people are using the bionic leg as a fashion statement
  • How Japanese professors make product development difficult
  • Why it is often so hard for Japanese startups to sell to Japanese consumers

Links from the Founders


Welcome to Disrupting Japan. Straight Talk from Japan’s most successful entrepreneurs.

I’m Tim Romero and thanks for joining me.

Today we’re going to talk about bionic legs, the real deal, a battery powered below the knee powered prosthetic leg that is already being used by amputees all over the world, and it looks pretty good too.

We’re going to sit down with Xiaojun Sun or Sunny, as he likes to be called. The founder, and CEO of BionicM who lost his leg when he was nine and spent the next 15 years determined to do something about that, and he did. BionicM is a Japanese startup creating artificial limbs that are not just functional or practical or good enough, but are different and innovative and well, to be honest, kind of cool.

We’re going to talk a lot about Sunny’s journey and the BionicM prosthetic leg, but we also talk about why it’s easier to launch this kind of product in America, despite the stricter certification requirements. The challenges in figuring out who the actual customers for artificial limbs really are and why Japanese universities have so much trouble getting their deep tech startups out of the labs and into the market.

But, you know, Sunny tells that story much better than I can. So, let’s get right to the interview.


Tim: We’re sitting here with Sunny Xoajun, the founder and CEO of BionicM who makes a robotic prosthetic leg, and thanks for sitting down with us.

Sunny: Ah, thank you. I’m very glad to be here.

Tim: So, I’ve given a brief description of what you do, but I’m sure you can explain what BionicM does much better than I can. So, what does BionicM do?

Sunny: Yeah, we are a startup company, spin of the Tokyo University. We are building a powered prosthetic leg to have the handicap improve their mobility.

Tim: Why is the powered prosthetic leg important? What’s the important part of having the active?

Sunny: Currently, most of the prosthetic is unpowered. We’re developing something different from the current products which has a power to have user walk more easily. Perhaps do something which they couldn’t do with current products.

Tim: It’s battery powered electric motors. What does this leg do for users that passive prosthetic legs cannot do?

Sunny: For example, it’s very difficult for some elderly amputee to stand up because when they stand up with the passive prosthetic, there is low power to help them, so they have to rely on their sound leg. If their sound leg doesn’t work very well, it’s difficult for them to stand up.

Tim: Okay. So, the power in the BionicM leg duplicates the muscle power that is in a regular human leg for things like standing up from chairs or going up and down stairs and things like that.

Sunny: Yeah, you’re right. It works like a muscle. So, it will give a power to have user do something. For example, when they use it to stand up, they can get the power from the prosthetic. So, it’s easier for the user to stand up, of course they can do something like going upstairs or downstairs.

Tim: Okay. And I want to really dig into the details later, but it’s fascinating. So, it’s battery powered and so how long does it last on the charge? Is it charged like once a day? The user uses it all day.

Sunny: It can be charged fully for three or four hours. So, it can last for one day.

Tim: Oh, okay. So, users just charge it overnight?

Sunny: Yeah, yeah. Right.

Tim: And how much does it weigh?

Sunny: It’s about three kilogram.

Tim: Three kilos? Yeah. Oh, that seems quite light.

Sunny: Yeah, we did a lot of work to make it light weight. So yeah, it’s quite light weight.

Tim: And tell me about your customers. Who’s using BionicM now?

Sunny: Right now we are just commercialized our product this year, so we’ll develop our product to the US market. So, right now we’re developing some kind of business in the US. So, we hope amputee in the US could use our product.

Tim: So, now it’s just in sort of the testing and evaluation phases?

Sunny: Yes. We have done every test, right now we will manufacture our product in September. So, we are applying for the FDA in September. And then we will sell our product in the next year.

Tim: Well, and I understand you are BionicM’s first customer and beta tester yourself, right?

Sunny: Yeah, you are totally right. In fact, I started to do this research while at the university. At the beginning I tried the prototype by myself and did many improvement. After we build the company, I’m also the first user to try every new prototype. I have used this prototype for over two years.

Tim: Just to make sure our listeners understand what that statement means, can you tell a little bit about your own story, about why this is a special passion for you?

Sunny: Yes. I got my right leg amputated when I was nine years old because of the bone cancer. At that time, there was difficult for me to afford a prosthesis, so I worked with a crutch for 15 years. 10 years ago, I got a chance to study in Japan, and then I got my first prosthesis, some financial support in Japan. It was great. It changed my life, and for the first time my hands could be free. I can do something which I didn’t do before.

Tim: So, it’s like your first time not on crutches since you were nine years old?

Sunny: Yeah, it’s quite difficult because when you walk with a crutch, I cannot hold the umbrella when it’s rainy. I cannot take my own something or I go to restaurant. So, that’s quite tough.

Tim: Wow. And what happened then?

Sunny: It was great at the beginning, but after I use the product a lot, I also found there was some issue of current products. I was an engineer in Sony, so I was wondering whether I could design better product for myself and other people. After I think a lot I should do this. So, I quit my job and then came back to the university as a PhD student. And then I began to do this research in my PhD study.

Tim: So, the BionicM project was started in 2015?

Sunny: Yeah, 2015. Yeah.

Tim: And let’s see, just so we can get the timeline. So, 2015 is when you started this research project?

Sunny: Yeah.

Tim: And Bionic and the company you started a few years later?

Sunny: Yes. in 2018 I got my PhD degree, and then at the end of the 2018, I built this company.

Tim: And you’ve gotten a steady stream of awards? I can’t list them all here because the podcast is not that long. But both in Japan and overseas. So, have these awards led to partnerships overseas, have they led to increased funding?

Sunny: Yeah. First I know many people. So, some of them are investors, we talk about the investment about our company. And besides, we want to develop our business in some countries so they can introduce some people. Some people I think it’s a great chance to expand our level work, to know more people, to know more investors.

Tim: So, let’s talk a bit more about the product itself. So, what’s the total cost for the user of these prosthetics?

Sunny: In fact, in the US it’s covered by the insurance. So, the reimbursement will be the $45,000.

Tim: So $45,000 in the US and similar price in Japan?

Sunny: Yeah. Similar in Japan.

Tim: And it is that high, is that low? Is that average for prosthetics in general?

Sunny: It’s quite high because it’s the high end product, so because it has a power, so it’s better than the current high end product. So, it’s higher than current high end product.

Tim: Okay. What’s been the reaction from the test users so far?

Sunny: Yeah, we did many tests in Japan, and we are also doing some tests in US. We got a lot of feedback, for example they found that it’s easier, it’s less tiring for them to use our product. It’s easier for them to stand up with our leg because when they use some traditional product, it’s quite difficult for them to stand up.

Tim: What’s involved when someone is fitted for a bionic and prosthetic leg? What’s the process? Is there a lot of customization and training for each user? Is there a period where the user needs to be trained on how to use it? What’s the whole process?

Sunny: Our product is standard which means it’s a mass production product. We don’t do any customization, but each amputee has different heights. So, some customization should be done in this process. So, we will sell our product to the prosthetic clinic where they will do the customization for the end user. They will make some interface which is called the sockets to link their body to the processes. So, they will make the socket by automate, and then they will same knee components with the saw sockets. So, we don’t sell our product to the end user directly. We sell our product to the prosthetic clinic.

Tim: Well, actually that was one of the things I wanted to ask you about. So, in the marketing of this product, I mean, we know who the user is, but who’s the customer in the sense? Who makes the buying decision? Is it the doctors or the technicians? Or is it the end users who really controls that decision really?

Sunny: Yeah, in US it’s a medical device. The doctor need to give a prescription. So, finally the doctor will make a decision. But most of doctors don’t know the prosthesis very well. So, they will get some advice from the technician which is called the CPO. The CPO is low process very well. They will do the fitting. They will choose what kind of knee component should be used. So, as they will talk with user, they will consider user’s mobility level and their body condition and their residual stem, and what kind of left they want in the future with the prosthesis. They will hear everything from the end user and then they will give advice. And then this advice will be given to the doctor. The doctor will write a note, this note will be delivered to the insurance company.

Tim: So, the key to the market really sounds like winning over the technicians and making sure they understand the benefits?

Sunny: Yeah, you are right. So, as a technician is the most important key person in this process, they will decide what kind of product should be used.

Tim: And is that the same everywhere? Is that the same In Japan and the US?

Sunny: It’s quite the same in Japan and the US.

Tim: So, what’s involved in getting a prosthetic approved as a medical device in Japan and in the US?

Sunny: In fact, in Japan it’s already a medical device. We don’t need to get any really approval. It’s quite easy to sell products, doesn’t need any requirements.

Tim: Wow, okay. But in the US there is?

Sunny: Yeah, in US it’s medical device too. So, you have to get the IFDA clearance if this product should be covered by the insurance, you need to get the insurance approval.

Tim: But since it’s not a medical device in Japan, does that mean it’s not covered by the national health insurance?

Sunny: No. So, it’s not easy to sell this high-end product. It’s because it’s not covered by the insurance.

Tim: You mentioned that you’re in process of getting the approvals hoping to launch soon. When do you expect to be able to get those?

Sunny: Yeah, we plan to launch our product by May next year.

Tim: And how are you going to market? Are you going through partnerships with the major medical device manufacturers? Are you going direct to the clinics?

Sunny: Right now we are trying to get some partnership with some company in US, so they can help us deliver this product to the clinic. Of course, if it’s difficult to get a partnership with the company in US, we also have a plan to deliver this directly to the clinics.

Tim: So, the distribution plan is fairly similar in all the markets. Your first choice is to go through, find a medical device distribution partner?

Sunny: Yeah. Yeah. Our first choice is to find out a medical device distributor, and then we will sell all the product to the distributor and they will sell this to the clinics.

Tim: So, how big is this market? I mean, it seems weird to call it a market, sometimes, but I mean, how many people could this help?

Sunny: Yeah, in fact there are about 40 million amputees all over the world.

Tim: 40 million?

Sunny: Yeah. A lot.

Tim: Yeah, it is. And how many of those are fitted with prosthetics?

Sunny: Quite different in each country. Maybe in developed countries, 50% of the amputee have a prosthesis. But in some developed countries maybe 30% of amputee have a prosthesis.

Tim: So, looking at, for example, the US market and the Japan market, how many people would you be looking at?

Sunny: In US, we did some research. We found that there are about 2 million amputees, including above and below the knee amputees.

Tim: BionicM seems like a very different kind of product in this market, in that you are marketing this as  very much a technology company. So, I know you’re already at work on version two and there’s something to be said for making it look cool I think. Is this something you see as your users? I don’t want to say like a fashion statement, but something more than pure utility and something more than pure functionality. Do you see your users like upgrading to new versions? Do you see it as that kind of a product?

Sunny: Yeah. We really focus on the appearance. Currently, most of the product looks not so good, so the user try to hide their prosthesis. So, we want to do something little bit different. We hope that this kind of the product could be a fashion or personality of the user. So, they can show their product if they want. When they show their product, they will become more confident with their products.

Tim: That’s a very different approach. So, you are thinking in some ways is almost a statement about the user themselves.

Sunny: Yeah. Hopefully the device could be like glasses. In the past, glasses are for people with the handicap of their eye. But, right now most people are wearing glasses don’t think they have any handicap.

Tim: That’s right. Glasses are just another fashion accessory.

Sunny: Yeah. It’s a fashion accessory. So, we hope that in the future the prosthesis could become a fashioning like glasses even to some amputee wear this kind of the prosthesis. It’s a fashion, it’s a personality, not a handicap.

Tim: That would be pretty amazing. So, in your new version, what are you working on to improve in the new version?

Sunny: Yeah, in fact, we have some feedback from the user because we have the motor in our product. This some kind sound.

Tim: Yeah, yeah.

Sunny: Some people like it, they think it’s kind of the…

Tim: .. cyborg sounding …

Sunny: Yeah. It’s like a robot, but some people don’t like it because they don’t want other people to know they’re wearing a prosthesis. So, this sound will tell other people, they are using prosthesis, so they don’t like it. So, in our second version, we’re trying to develop some product which could be quieter so they can get the power from the knee, from the product, but it’s quieter. Other people don’t know they are wearing a prosthesis.

Tim: Earlier this year you raised about 3 million. So, congratulations.

Sunny: Thank you.

Tim: What is that money used for? What’s top priority for BionicM right now?

Sunny: Right now, all the money is used for going into US market. So, as I said, we need to get FDA clearance, we need to get the insurance approval. So, right now we are preparing for FDA application, the insurance application. So, it takes a lot of money. We have over 50 members, so it takes a lot of money to pay.

Tim: Tell me a bit about the manufacturing process. Where are you getting this manufactured? Because it’s incredibly specialized device.

Sunny: I cannot tell you the name, but yeah, we are doing some kind of OEM. So, we design everything by ourselves and then we will ask some company to mix this for us.

Tim: Can you say whether it’s being made here in Japan or whether it’s in China?

Sunny: We want to reduce the cost, we are making a product in China.

Tim: Okay. Your staff is split between Japan and China as well, right?

Sunny: Yes.

Tim: Yeah, Is that mostly the hardware engineering group is in China? Or how is the split working out?

Sunny: In fact most of our engineers are working in Japan. Yeah, they’re Japanese, so very few engineer stay in China. They are responsible for this kind of the smartphone application and some manufacturing.

Tim: But what does the smartphone application do?

Sunny: So, they do the can check everything with the smartphone application. For example, they can do the battery remaining. And besides the technician could adjust everything with the smartphone application according to each user’s request. For example, if the user want to work more fast, the technician could speed up the power to make it more work fast.

Tim: Yeah, I see. Because I was wondering about that because we all, I mean, in one sense, all us humans walk the same way, but it’s pretty different the way different people walk, not only based on like height and things. But like some people walk faster, some slower, and so you can customize that with the smartphone app.

Sunny: Yeah, we have a basic model which could assimilate most people’s walking. But you know, there are many kinds of amputee, for example, very high activity amputee, some do activity amputee. So, we need to customize these parameters according to each user’s request.

Tim: All right. And I’m curious, so you were talking before about the user feedback and the request from the users to improve the product. And before you were mentioned the real decision makers were the technicians at the clinics. Did they give you similar feedback or did they have their own special needs and requests for the future product?

Sunny: In fact, we also got many feedback from the technicians. So, they will have their user try our product so they can know what should be improved, what’s the benefit the user could get. So, we also got many suggestions from these technicians.

Tim: So, let’s talk a bit about Japan and the University of Tokyo specifically. So, it sounds like the University of Tokyo has been super supportive of your research and your spin out. In fact, I understand that a lot of the technology that went into the prosthetic leg is based on University of Tokyo research on robotic bipedal walking. They also provided research support, some investment connections. It sounds like a great program. Is there anything missing? Is there anything more the university should be doing to accelerate startups?

Sunny: Yeah. I think in recent years the university did a lot of work to help the young students to build their company. I also got many support from the university. At the beginning we don’t have any money to rent the office, the university offer us a place in located in the university, in the campus.

Tim: We’re sitting here in the middle of University of Tokyo campus.

Sunny: Yeah, it’s very great. In Japan, the credit is very important, which means it’s not easy for young company, for a startup to be trusted. So, if we have address with a university, we can get more trustee.

Tim: Well, I imagine that’s especially true with medical devices and medical startups.

Sunny: Yeah, you are, right. It takes the time to develop the product, so it’s related to humans safety. So, people take care of this company’s status. So, they rarely see, well, we as a company come to run since we spin off around the university, we got many supports. We also got the backup from the university. This is very important for us.

Tim: Okay. So, that credibility and that trust that comes with being a university spin out is one of the most important aspect of the university support.

Sunny: Yeah, I’ll think so.

Tim: That makes sense. A lot of university researchers, either PhD students or postdoc, have a bit of a shock when they change from university based research to product development research. Did you go through that transition or it sounds like you were always kind of focused on the product from the very beginning.

Sunny: I want to design better product for myself. I quit my job from the company. So, I had some experience about how to design products. After I go back to university as a PhD student, at the beginning I try to develop a product instead of doing basic research. So, that’s quite different for other researchers.

Tim: Did your advisor try to get you to do more pure research?

Sunny: Yeah, because my professor always told me, if you want to get your degree, you have to publish some paper, which should include some basic research.

Tim: You know, this is something that I see a lot at Japanese universities. There’s a real split between the applied research and the pure research and Japanese university research really strongly favors the pure research.

Sunny: Yeah. In university, the professor, the students always spend a lot of time on their fundamental research. They’re trying to do something different in some saying innovative.

Tim: But it sounds like, I mean, UTEC and some of the other programs have certainly helped and supported you in that.

Sunny: Yes. In recent years, the university also want to help the students to build their company. So, there are many programs for those students who want to build a company. I use that program, so help me to build my company.

Tim: That’s great. Well, listen Sunny. Before I let you go, I want to ask you what I call my magic wand question. And that is, if I gave you a magic wand and I told you that you could change one thing about Japan, anything at all. The education system, the way the national insurance works, the way people think about risk, anything at all to make things better for startups in Japan, what would you change?

Sunny: I think people should be more open for the innovation for the startup because the startup company cannot make a perfect product at beginning. So, the customer or the people all around should have more patience for this startup for their products, give them more tolerance, give them more time to make their product better.

Tim: Japanese customers are famously demanding.

Sunny: You’re right.

Tim: So, you think it’d be easier if Japanese customers would be a little more forgiving of startup technology?

Sunny: Yeah. As you said, Japanese are very demanding. So, it’s a good with this demand that people try to develop good flow product. But for startup, it takes time, takes money to develop a perfect product. So, the people should be more patient. The system should be more patient for this startup. If they have more patience, this startup will become better. They will be more, more startup.

Tim: I think so too. And that’s one of the things in America, it’s perfectly normal for a startup to go with an MVP. A very simple, very scale down product that basically work, and that’s okay. But from your experience in Japan, you can’t?

Sunny: No, you cannot do that. You have to develop almost perfect product. If you cannot do that, you cannot deal with your product to the customer.

Tim: I agree with you. And also like in the long term, it’s kind of good because you end up with really high quality. But I can see in the short term it can be extra hard on startups. But it sounds like you, you’ve struggled through that and made a success of it.

Sunny: Yeah, kind of.

Tim: Slowly?

Sunny: Slowly. Yeah. It takes time takes seven years for us to deliver our product. So, it’s not so either.

Tim: Well, what, what kind of feedback did you get? What were the things that they were so strongly demanding about? What should they have been more forgiving about?

Sunny: For example, the hope is to be more quiet. We did something, we tried to improve the noise, but takes time to do this improvement.

Tim: Whereas the US, the users were a little more understanding?

Sunny: Yeah. We did some trial in US. We found that in US people could be more understanding the noise. They can accept the noise. They think it’s quite cool. They think it’s works like a robot.

Tim: Well, it does sound cool when you came over to the door to say hi, it does sound cool.

Sunny: It depends on people.

Tim: No, of course. Yeah, because it’s loud enough to hear for sure. So, I mean that is interesting. So the American style of like, okay, well it’s not perfect, but it’s good for now. Would be much more useful in Japan too.

Sunny: Yeah. In US, we found that maybe they like this design, they like this appearance, or they like this kind of the power assist function. They think it’s good enough. Maybe noise is an issue. In the future you need to improve it, but they can accept the product now.

Tim: Yeah. I think a lot of founders probably share that experience.

Sunny: Oh, really?

Tim: In all industries here in Japan. Well, listen, Sunny, I want to thank you so much for sitting down with me.

Sunny: Thank you very much for having me here. Yeah.



And we’re back.

Sunny’s experience really highlights one of the core challenges Japanese universities are facing today in productizing their deep tech research. The potential is huge, but as Sunny experienced, there’s a strong bias in favor of abstract fundamental research and against the kind of applied research in engineering that is required to actually bring a new product to market.

Oh, and for the record, the servo motors in the BionicM prosthetic leg are pretty loud. I tried to make a recording of it for you, but I just didn’t have the proper equipment with me at the time. The leg is about as loud as a quiet conversation, and it sounds a lot like the T100 from the first Terminator film.

It’s actually pretty cool sounding in a futuristic robot cyborg kind of way. But I can totally understand why that’s not really what you want when you’re walking to your desk through a quiet office. It’s a cool sound effect that users will probably want the option to turn on and off depending on the situation.

And that’s something I love about Sunny and Bionic m’s approach. Prosthetic legs can be used and should be used as fashion statements and Sunny’s comparison to eyeglasses make a lot of sense. Eyeglasses have long sense moved beyond being a simple means of compensating for a disability and have become firmly established in the world of fashion with many global fashion brands selling frames.

Why shouldn’t artificial limbs follow the same path? Sunny’s vision is inspiring. It’s one of making artificial limbs not just functional or good enough, but something that’s different, innovative, and even cool.


If you want to talk more about artificial limbs and medical innovation in Japan, Sunny, and I would love to hear from you. So, come by disrupting and let’s talk about it. And hey, if you enjoy disrupting Japan, share a link online or just tell people about it. Disrupting Japan is free forever, and letting people know about it is the absolute best way you can support the podcast.

But most of all, thanks for listening. And thank you for letting people interested in Japanese startups know about the show.

I’m Tim Romero and thanks for listening to Disrupting Japan.