Tiny Bubbles, Big Impact: How Nano Bubble Tech is Transforming Water Cleaning
“Water already contains what we need—we just help it do its job better.”– Natsumi
Every year, trillions of gallons of water are used to clean homes, hospitals, and industrial facilities—often with harsh chemicals that strain both human health and the environment. But what if the answer to cleaner, safer water wasn’t a new chemical, but smaller bubbles?
In this episode of Liquid Assets, host Ravi Kurani sits down with Natsumi Ito, co-founder of Water Design Japan, to dive into the transformative potential of Nano Bubble Technology. Based in Tokyo, Natsumi and her team have developed a remarkably simple yet powerful device that turns the air already in your water into microscopic cleaning agents—without adding a single chemical.
From medical clinics to semiconductor factories to the showers in everyday homes, this tech is reducing chemical use by as much as 60%, cutting labor costs, and offering a low-cost, install-and-forget solution. Ito shares her journey from global citizen to impact-driven entrepreneur, her work with former Mitsubishi execs, and her vision for scaling this clean water innovation globally.
What You’ll Hear in This Episode:
- How nano bubbles clean surfaces without chemicals
- The science behind why these invisible bubbles don’t float but vibrate like molecules
- Why Japan’s hospitals and semiconductor facilities are early adopters
- The origins of the tech—from Hiroshima’s oyster farms to modern plumbing
- How Natsumi went from Taiwan and the U.S. to leading one of Japan’s most innovative water startups
- Why traditional chemical cleaning may soon be obsolete
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📺 Watch the Interview
Meet Natsumi Ito
Natsumi Ito is the co-founder of Water Design Japan, a startup that uses nano bubble technology to reduce chemical use in cleaning and water treatment. Her team has developed a nozzle that can attach to almost any water pipe and transform the air already in your water into nano-scale cleaning agents that stay active for up to two years.
Natsumi's journey spans cultures—growing up in Taiwan, studying in the U.S., and now building a globally impactful startup in Tokyo. Alongside her co-founders, including a former Mitsubishi Chemical executive, Natsumi is bridging cutting-edge Japanese technology with global water challenges.
Transcript
00:25
Natsumi Ito
Way the bubble moves, it does like this like brownie movement like, which is similar to like molecule, like moving like side to side, top to bottom. So like bubble is like actually like moving kind of like this like just like vibrating like moving around. That's why it can stay in water like very long time and eventually go underneath the dirty thing. Because the way we generate the bubble, it has the negative charge around the bubble and most of the dirt or like surface has plus so dirty thing like goes under and then the bubble can eventually go underneath and then like when there's a flow, the water like can like cleanse it all.
01:06
Ravi Kurani
I'm your host Ravi Kurani. Liquid Assets is a podcast that talks about the intersection of business, technology and policy, all as it relates to the world of water. Today we have an amazing guest for you. We have Natsumi Ito.
01:18
Natsumi Ito
Hi everyone, I'm Natsumi, co founder of Water Design Japan. And we solve clock pipe and damages without using chemicals with the technology called nanobubble.
01:28
Ravi Kurani
Natsumi, how are you doing today?
01:30
Natsumi Ito
Good. How are you doing?
01:32
Ravi Kurani
I'm doing good. I'm doing really good. You said what time is it over there? You're in Japan right now, right?
01:36
Natsumi Ito
Yeah, I'm based in Tokyo right now and currently 11pm okay.
01:42
Ravi Kurani
It's. It's 9, 9:30pm or 9:30am here in New York City.
01:47
Natsumi Ito
Yeah. And you still in Wednesday, right? Oh no, it's Thursday too.
01:51
Ravi Kurani
We're in Thursday now. Yeah.
01:53
Natsumi Ito
Okay. So we on the same day at least.
01:57
Ravi Kurani
Cool. Why don't we jump off? We had an awesome conversation when I saw you last at the Consumer Electronics show in Las Vegas. We have a ton of stuff to talk about today and so I think what we should actually jump into is let's just get down to the meat and potatoes, right? Let's just kind of open up with who you are, what you're working on and let's just jump right into nanobubbles because nanobubbles is theme of today's conversation.
02:25
Natsumi Ito
Yeah. Well, thank you so much for having me today. My name is Natsumi, co founder of Water Design Japan and we do a Nanobubble technology. What? Nanobubble is pretty much like a very small tiny bubble. It can last in water up to one to two year and bring a cleaning benefit. So our goal is essentially to reduce the amount of the chemical from industries. And our solution is like very simple. Like this, just the tiny nozzle. This is the smallest one. And this was the one actually were showcasing out of ces. This one you attach to a shower head bottom like through the hose. And when the water passed through, like, see like the inside like a little like a structure. This is the core element and it doesn't reduce the water pressure.
03:09
Natsumi Ito
And then when water get through it, we transform what's existed in the water into a nanoscale. So we're not changing water quality, purify anything. So our core technology, which is like more like bigger one, like we have been like introducing like this bigger guy, like to industrial application, like has been used like more than 10,000 location like around the world right now. And we have been able to reduce the chemical amount or like reducing the water usage by improving the like filter efficiency and so on. So yeah, like that's what let's.
03:49
Ravi Kurani
I want to kind of go back and you guys make tiny bubbles that last in water for about one to two years. You said what is a tiny bubble? Like is this like when I turn on my tap and I, you know, see the bubbles that are coming out, I'm just going to kind of ask the stupid questions because.
04:05
Natsumi Ito
No, no, it's fine.
04:06
Ravi Kurani
How does it work? Like what, like how big are these bubbles? Can. What's going on?
04:11
Natsumi Ito
Yeah, so like I say like it's nano bubble. And like when people hear like the bubble is like probably like, oh, like it's like you can see with the like a visual eyes, but like nano scale is like really tiny. So you cannot see like even like when we generate the like water like faster, like this like nano bubble water, like you don't see the bubble in the water. So the water that we drink every day, like it has like H2O, like so it has the air already inside and we just simply like pass through this nozzle to create what already exists in the water into a nanoscale. So we're not changing the like water quality like purify or anything. Like just simply like what we just using what's already existent in the water into a like smaller scale.
05:01
Natsumi Ito
And, and nanoscale is like really, really tiny. Like I think like everybody remember during the COVID Time like the COVID virus is like super small, about the same size.
05:13
Ravi Kurani
Okay, so you had mentioned that there's already air in water. Water is H2O, right? Two hydrogen, one oxygen. When the water is going through your device, anabubble device, are you like, are you injecting more air? Like how does, how do you get more air? How do you take the air that's already in there and make it tinier?
05:38
Natsumi Ito
So like we just simply using the water as the ingredient, like as a, like, you know, like things to like generate. We could have like a different inlet to like have like inject different type of like gas like oxygen or like a CO2 or hydrogen and things like that. But we don't do that. Like this one is like simple like nozzle. Because there are a lot of way to generate a tiny bubble. Like not like especially like nano bubble, micro bubble, fine bubble. Like those category. And when you inject gas or like outdoor air, it caused the contamination in the water. And especially in the sensitive places like medical or like semiconductor. Like those place you can't do that.
06:25
Natsumi Ito
So those place is the like actual like place where people is like facing a lot of like chemical usage and like they want to reduce the water like usage and all that. So our solution is the only one has been able to like use in the medical and like those sensitive places.
06:43
Ravi Kurani
Awesome. Really cool. So kind of backtracking for the audience. You guys have a nanobubble technology. You're able to just basically take the existing water, tap this onto a pipe, and you. There's no pressure decrease. So you're not like changing the flow rate. There's no, there's no decrease in the speed of the water that's flowing through the pipe. And then basically you take the existing water that already has air inside of there and you just make tinier bubbles out of the already existing bubbles that are there. And this you said helps keep the water cleaner or like what's the, what's the kind of end goal here? You had mentioned kind of hospitals and your different applications. Like how does it, how does it keep it clean if you're just introducing more, not introducing more air, but making tinier bubbles.
07:34
Natsumi Ito
Thank you. So this like device is not a filter. It simply generates a tiny bubble which is the nanoscale, like nanobubble. And when the nano bubble becomes like a scale, like a small, tiny like nano bubble, like it, you know, like when you buy the sparkling water, the bottle, like you open it and then like it like it makes the sound like. And then like you see the bubble like goes like up due to gravity and like the normal like those like a bubble that you can see in the water like visually like usually like floats on the surface like around like 8 to 10 seconds. And when the, those like bubble becomes like more like a micro bubble, you will start seeing the bubble is like in the water. Like kind of like water becomes white.
08:26
Natsumi Ito
Like when you generate like the water becomes like a white like a silky water that's like a micro but like it still does like a gravity movement. So like flow like from bottom top so it moves slowly but like around like 12 to 14 minutes around. And the bubble will like eventually lose. And then like the water becomes clear and then those like bubble loose. But nano bubble is really small and tiny. And an interesting characteristic is that like the way the bubble moves, like it doesn't like go floats on the like due to gravity like this like bottom top movement. It does like this like brownie movement like which is similar to like molecule like moving like side to side, top to bottom. So like bubble is like actually like moving kind of like this like.
09:18
Natsumi Ito
Yeah, it's like a star like just like vibrating like moving around. That's why it can stay in water like very long time and eventually go underneath of the dirty thing. Because the way we generate the bubble, it has the negative charge around the bubble and most of the dirt or like surface has pl. So dirty thing like goes under and then the bubble can eventually like go underneath and then like when there's a flow of the water like can like cleanse it off. So that's why nanobubble can. It's not like a hundred percent alternative of the chemical. But were, we have been able to help the industry or like a home usage like everyone to reduce the amount of the chemical.
10:02
Natsumi Ito
Like let's say like for home like detergent usage or like the how frequent you clean the pipe or like how frequent you clean the toilet. Like when you don't clean. Like there's like a black thing like brackling ring created due to a biofilm. Like those things nanobubble prevent it. It's not going to be 100% alternative. Like you still have to clean but like a cleaning term tend to get longer or like the amount of the chemical you use tend to get reduced. So that's.
10:35
Ravi Kurani
And what are you seeing in terms of reduction of chemical use? Like if you were to pick an application like washing detergent or your toilet, what were you doing yesterday? And then if you had nanobubble technology on there, what are you seeing today?
10:49
Natsumi Ito
So for detergent and stuff is like hard to say because like depend on the household. Like the amount of the detergent that they use is difficult. I mean like different. So I always give you like example that more like the industrial side and we use it for dialysis for medical device cleaning. And were able to reduce around like also like scale this hospital as well. Like some hospital has like a hundred like beds or like 20 beds. So amount of the chemical that they're using is like very different but around average of like 60% chemical reduction per month. And wow, that was a lot. So they. And this is also like one time purchase. And most of the like a case like return on investment, like close it like around like two or three years.
11:43
Natsumi Ito
And another case like we also use for like lately we've been testing for like semiconductor. This is not for like reducing the chemical. But they had a lot of people in line for cleaning like picking up the packaging like chips like one by one. And like human is like using the swab to like clean the surface because the cleaning failure was like so high. So they have to like manually like human is like cleaning. So we use in that line and we improved the cleaning efficiency by up to like 92%. So instead of having six people in line, like were able to cut just one person.
12:23
Ravi Kurani
Oh my gosh, that's crazy.
12:25
Natsumi Ito
That reduce a lot of labor cost.
12:29
Ravi Kurani
And so if I understand correctly, like just taking like kind of the toilet example or the dishwashing example just for the sake of kind of the audience being at home, the nanobubbles basically have a negative charge as they go through as they're generated. Generally biofilm or trash or like dirt have a positive charge. And so these nano bubbles basically go in and kind of like separate out the trash or the dirty stuff, the biofilm from the water. And then basically.
13:04
Natsumi Ito
Yeah, more like surface I think.
13:06
Ravi Kurani
Okay. And then the. The detergent otherwise would be basically doing that job. And so it's actually like assisting the detergent in doing its job. And so you would have to basically you would use less detergent or less soap or less cleaning needed.
13:21
Natsumi Ito
Yeah, and also like more like longer you use the nano bubble. Nano bubble is like invisible bubble, but like it also like coat the surface and it stay on the surface level as well. So more you use like nano. Like you have to like try to like spray the water more like not like just one spot. Like you don't like spray the water like everywhere but like if you want to like have like a benefit in the shower room for example, you have to like on the like wall or like a mirror and then like everywhere and nano bubble will coat the surface. And after that like like scaling or like sometime like mirror like become like build some like a scale to like become like start to become white or like the floor gets like a pinkish like slippery thing.
14:14
Natsumi Ito
Like all of those is like due to biofilm and those tend to coated by the nano bubble and then it get clean. And after nano bubble is cleanse it and then like clean it prevent the biofilm to grow faster or even if the biofilm grows because nona bubble is there, it becomes kind of like a cushion so it's easier to like clean after. So we've seen the customer like they were facing like a hard scale issue and after using nona bubble becomes like more soft scale. So like not like instead of like rubbing hard like just like a sponge wipe and like easy to like do the maintenance.
15:01
Ravi Kurani
And how many like I assume there's some sort of density required of nanobubbles created inside of a, a bucket of water. You know, I know it's going to depend on how big the surface area is on the wall. But like if you can walk us through an example of like you know you need 5 gallons of water to do you know 20 square feet or whatever in meters. What does that look like? What is like the equation of how many bubbles you need? How long do you need to run this attachment that you have to generate the right amount of bubbles to then like coat the wall and then that lasts for like two years or every six months or three months. You need to kind of recode it. What is, what does that look like?
15:43
Natsumi Ito
So like just the our nozzle like it's considered as the water pipe so you don't need to maintenance or anything. And how much bubble needed in order to have like XYZ amount of the cleaning benefit. That's something we are trying to map it out to like figure it out more like closely as well. Because nano size bubble is like really tiny. And there's like a world class like a standard like observation unit exists but the area that they were trying to look at is really tiny. So in order to use those machine to get the right data like you need to like circulate like let's say like you have to like circulate like multiple times to like create like more higher density of the bubble of the water.
16:30
Natsumi Ito
And then if you are lucky like the bubble will be like captured and you can count it. But that's not ideal in the like a real lifetime. Like if you are using at a factory or like place like you want to like check it every time. So we partner with one of the engineer company and we developed the observation unit as well. So that's something like we are trying to figure it out. But as far as we learned so far higher the bubble tend to bring more cleaner benefit.
17:05
Ravi Kurani
Really interesting. And so I guess just kind of digging into something you said earlier. Like I know the observation unit as you were saying, needs like a closed loop until you have a certain amount of bubble density. But if you're in this restaurant setting again, right, like we're kind of going back to that biofilm on the wall or biofilm on the floor. Do you need to kind of like. Do you see applications that have like a closed loop and it has to like you know, run in the closed loop for 30 minutes or something and then you can kind of unleash the water because it has a high enough density or do you just put this on the pipe and then just basically.
17:44
Natsumi Ito
Start spraying for the like a standard homes or restaurant, like dentists, like hair salon. Like all those application like we don't do the circulation and we have the customer like is very happy and they've been like using for quite a long time. And those applications you simply. This is like a water like nozzle, like connector pretty much. So you cut the pipe and install it.
18:09
Ravi Kurani
That's it. Really cool. Yeah, it's very simple that you don't have to like add any chemicals. You're like, you're just changing the consistency or the size of the air and the water to basically get it to be able to be more efficient.
18:26
Natsumi Ito
Yeah, because I think you know like nowadays like everywhere in the world like we want to clean thing and we have been using a lot of chemical like even for pool like chlorine to like you know like sustain the like a cleanliness of the water. But is it actually that much necessary? And then if we can replace it something that we have been already producing which is like water like has a like air in it and then we just changed like the size the bubble like simply then that might better.
18:59
Natsumi Ito
And our goal is to like reduce the chemical amount from the industry like around the world and like not to just like sell it to like whoever just want it but like we want to find the actual place who's actually looking for this like kind of solution because Japan is really like clean water and then I think we are rich in terms of like a water like natural sources and all that. But around the world is like different story and a lot of places like facing like hard like water issues and things like that. So we want to help those like places to find where is the actual right place to meet looking for this kind of like solution.
19:40
Ravi Kurani
Super, super inspiring. Let's go back to the founding story. I'd love to understand what makes Natsumi tick, right? Like why did you. You're. You're one of the co founders. Like walk me through the kind of origination story of the company and let's learn a little bit more about you.
19:57
Natsumi Ito
Okay. So I'm one of the co founder of Water Design Japan and I was always looking for a technology it can apply for like global scale to solve the global issue. And I'm not the like technology founder of the nano bubble itself but and the actual like product founder of the is ex CEO of Mitsubishi Chemical Cleansing. He's like heavily like knowledge about like water and like engineering and like he expand the water purifying machine entire Japan pretty much. And he was selling like a water purifying machine like which is like more like a cartilages right. And after World War II like our like Tokyo like Japan's water like needed to like filter lies because the amount of the chlorine the government was using was like more higher. So the taste of the water was different.
20:56
Natsumi Ito
And then like those like purifying machines was like needed like from the customer side. So like it expanded more and more but like you know like time pass it and then like governments like a water treatment like system and everything like got improved. So it's not that much necessary to have much of a like a filter replacement. But just the size of the business like carlage is like changing and then keep like kind of like subscription. That was the business model but it's not that necessary.
21:32
Natsumi Ito
So he wanted to after like he retired the his like Mitsubishi's like position like he wanted to actually found and like leave something good for the future which is not a bubble technology because like around like early 2000 this nanobubble technology was heavily studied like started off in Japan it was by the oyster farm like we have like one of the like biggest oyster farm in Japan and one of the prefecture called Hiroshima. You might know And Hiroshima has like one of the big oyster farm and they had the Red Sea poison issue and all the oyster died and they had like a 40 something million damage. And that time one of the professor got an offer to install a microbubble generating solution and somehow it worked. And that's how the tiny bubble research started.
22:27
Natsumi Ito
And Japan was like even the government was like a hype. And then they the government invested around like 2014 to accelerate this technology to grow. So around that time a lot of like researcher and then like generating solution maker scaling machine maker like these three stakeholder like try a lot and a lot of like research paper and all that thing like publish. And that time was especially in the like a plant science. And so that's why outside of Japan a lot of people see the plant science application like the plant growth and then like aquaponic, hydroponic.
23:07
Natsumi Ito
We see the result and we hear from the customer but we couldn't actually see the nanobubble to figure it out how exactly the roots is growing faster or like why the fish gets bigger or like why the shrimp gets healthier or like all those things like still you get the result but like questions. So we our like product founder he still like went on the like research and all that to figure it out. Like it might be actually useful more for like a cleaning benefit. And then he. He had a lot of like connection with the medical field because like this was it's patented and also water supply certification and passing the drinking water testing everything done.
23:56
Natsumi Ito
But it doesn't says like even if you have all those like app certification and everything it doesn't promise you it is generating nano bubble because there's no such organization is like you know like claiming like oh like you generating this much of like a nano bubble or nothing like that. So it was difficult to like get you know like by the you know like a trust from the customer and like it was like you know like the beginning of the water technology is always like kind of like a sketchy. So that's why he did the testing in the medical field and it was published at the Dr. Conference. And then we start introducing for the household and like individual like those like consumer side.
24:48
Natsumi Ito
And I met the product founder and my our like CEO like so like we are like three of us found it together and it's funny like our age difference is kind of like a three generation difference. Like I was in my 20 and then our like my partner is like he would. He was in his late 30 and then the product founder was in his late 60s. So now like everybody's like and we next month gonna be our fifth year of closing. So we go into like six years. So like everybody's like 70 and 40 and then I just turned 30. So it's kind of like a like dynamic difference.
25:33
Ravi Kurani
Yeah.
25:33
Natsumi Ito
And at the beginning like they were like who's this girl? Kind of thing. But I saw the potential of this technology so I pitched them and I, I took them to like a pitch competition and they're winning and that's kind of like how we started. Like I think it's kind of like a weird way, like an interesting way. Like it's not normal. Like like I, I was like doing study or anything. It's more like I was like looking, searching for like a different type of technology because I did grow up like outside of Japan and I did see the uniqueness of Japan as a Japanese when I came back to Japan from abroad and Japan is unique and someone needs to be the Brit to like close that like gap as well.
26:25
Ravi Kurani
Where did you live prior and can you like what did you, what differences did you see outside of water design Tokyo and this kind of technology in the Delta or the discrepancy between where you were and what Japan has?
26:41
Natsumi Ito
So I grew up in Taiwan and I went to school in the US and with my previous job I was like traveling to like San Francisco Bay area a lot and like back to back and like nobody knew about like this not a bubble technology first of all. And but like at the same time like Japan kind of like started to having like the bubble boom. Like it was starting like this bubble boom like started in the past, I would say four years. There's like a three shower head maker created like there's like a three like big ones. Now it's become more like a two. But like they created the hundred million dollar market in a year. So the non mobile technology was like always like having the hype.
27:33
Natsumi Ito
Like everybody was saying like oh like it might be like a big potential to create like a big market. But it didn't. And then finally it kind of like hit with the shower head and I was seeing all that. But like Asada Japan was like a complete different story. Like nobody didn't know anything about nanobabu.
27:55
Ravi Kurani
And what else did you see outside of nanobubbles in the the US Taiwan that like are opportunities that you see in Japan or it could even be cultural. Like is there any other things that stuck Out.
28:11
Natsumi Ito
I think like Japanese people is really good at like kind of like focusing one thing, continue to like do like teamwork to like a research type of thing. So there are a lot of good technology out there. And then like, but also at the same time sometimes it kind of like hard to ask them to like share all the data and everything. Taiwan, like Taiwan and Japan, like country and country wise. Like, like I used to live there and then my father was like a founding member like back in the time to open the Taiwan branch. And like, you know, like Japan like was you know, like taking over like Taiwan like back in long time. And then like some like elder people like still speak Japanese and then like it's like a good friendship, I think.
29:05
Natsumi Ito
So as a Japanese I go in Taiwan and then like trying to do business. It's not that hard. But like the language is very different still. So understanding the market is different. But I think us is like way like more different, like story, like the way the marketing works or like how like people always bring in the technology and like especially a startup like seeing like it's kind of like, you know, like fast growth, like kind of like bootstrap and all that. And as a like more hardware startup. We call it like us like as a startup because like the government is also like pushing the startup scene. But were kind of like a slow at the beginning and now like trying to like growth now. So just like seeing like the differences like the cultural like dynamic and all that.
29:57
Natsumi Ito
And also like hearing the BC from there like the perspective of Japan like Japanese people like difficult or like not good at like expanding. Especially like global expansion because like Japan is kind of like a galaxy at Lapagos island, like very different. And the language is different, culture is different, like business culture different, like all those things. And it's pretty much the bridge to like share to like all my team to like have the most understand because like it can be like you know, like changing like someone like a old like person's like mentality like right away. Sure.
30:35
Ravi Kurani
Yeah. Really, really cool. Natsumi, what are. So you guys had mentioned that you have a shower product and then you're. You're selling into medical. What are, what are the sweep of like applications that you guys have in. In Japan?
30:52
Natsumi Ito
So Japan's biggest market is home application? Actually. Yeah, about like 60 to 70% of our revenue come from household application. When people build a new home or like renovation, we work with a lot of like a developer, like a house maker, constructor, like design houses, like those people and like customer, like they cannot do a diy. Like they have to have a plumber, like who has the license to install it. So like that's how we work with those people to like kind of like a B2B2C application. And yeah, if they have a customer, they tend to also work with. Japan is small. It's not a U.S. Japan is the size of California pretty much. So a lot of building, apartment, all those things is very accessible. So they tend to also do hair salon or dentists, all those buildings. So that's the biggest application.
31:57
Natsumi Ito
But we also getting a lot of industrial side and we're trying to collect more data on that side as well.
32:04
Ravi Kurani
Really cool. Awesome. Thanks so much for joining us on the show. Natsumi.
32:08
Natsumi Ito
Thank you too.
32:09
Ravi Kurani
If people wanted to find you, where can they find you at?
32:12
Natsumi Ito
You can find me on LinkedIn. I think that's the easiest place. Or you can find our company website.
32:20
Ravi Kurani
Awesome. Thank you so much for coming on.
32:22
Natsumi Ito
Thank you.