7. Charging devices with the sweat of our fingertips. Feat. Lu Yin, nano-engineering PhD at UC San Diego.

TRANSCRIPT

[00:00:00] Lu Yin: you don't have to actively exercise to get sweat from your fingertip because even if you're sleeping or you're just sitting and doing nothing, your fingers emitting sweat all the time.

We can actually use the small amount sweat. It has a lot of chemicals within that can be, used in chemical reaction.

And then we use enzyme to break down, the components within the sweat to convert the chemical energy into electrical energy. We don't want to ask people to run for a mile to charge their wearables.

We want the people to have minimal amount of input, to, to harvest the maximum amount of power. And that's the problem we are trying to address right now.

[00:01:02] Mizter Rad: Welcome, beautiful people. Thank you so much for listening up today. Today we have a super interesting guest.

His name is Lu Yin. He's originally Chinese, but he lives in the US for quite a long time now. And he's an expert on biosensors, ..Wearable technology, flexible electronics, and harvesting energy from your own body. Now if this sounds super weird to you or a bit like sci-fi, you're in the right place just because Lu and I will have a conversation about all these topics.

We'll break them down as simple as possible so that everyone, including myself can understand them. We are all here on a learning journey, and I'm happy to drive the wagon. Lu, how are you doing today? How is Boston treating?

[00:01:54] Lu Yin: I'm doing well, uh, actually this year, of time Boston is, warmer than, the past year.

I'm here attending a conference. And, listening to a lot of interesting talk. It's a material research,conference. And, it's, exactly what I'm doing. So a lot of, newest progress from the field. I get to, get to talk to the researchers and,know what they're thinking, know what they're doing.

It's very exciting.

[00:02:22] Mizter Rad: That's great. That's great to hear. I used to live in Boston for a while. Beautiful city. We can jump into the topic right away because I think this is super interesting. to give a little bit of context beforehand, before we start talking about all this exciting technology, there is a term that people need to understand or we all need to have very clear, and that is what is wearable technology?

What are wearable devices? I understand from wearable devices that, they're basically internet connected appliances that you wear on your body. So let's say an I iPhone, sorry, an Apple Watch is a wearable device. the Fitbit wrist band is a wearable device. I've seen also smart shoes as wearable devices that track your steps and some other super interesting metrics.

[00:03:14] Lu Yin: In your opinion, how would you describe a wearable device? Just to start with the basics Yeah, that's a very good question actually. I was, giving a talk earlier today discussing about this. and what I was saying is that there has been a discrepancy between what, typical everyday people when they're talking about, wearable devices, what do they mean?

And when us researchers are talking about wearables, what do we mean? So when you think about wearable devices, of course, If we look at the market right now, it's dominated by, just typical miniaturized, electronic components that you put on your body. So when you are walking, when you're running, it stays with you.

it's something that you strap onto your body and, that's what we typically call wearable for consumer electronics. So typically like Apple Watch or any smart watches, even the. Wireless headset people are wearing more and more nowadays. and, for people with diabetes, probably they're familiar with the continuous glucose monitors, and the insulin pump that now becoming more and more wearable.

these things, typically stays on your body for extended amount of time, goes from several hours or for, cgm. those devices stay on you for 10 to 14 days without needing to taking, to take them off. that's what typically, in the consumer market, people define as wearable electronics, but for us as researchers, we put a actual layer to that, that we think something that's wearable must, be very conformal.

hence it needs to be soft . It needs to be flexible. Sometimes even stretchable if you want it to be really conforming to your skin surfaces. So in that regard, what we typically define as wearable is whatever we have defined on top of the consumer electronics. Also, we needed to have specific mechanical behavior.

So it needs to be soft, it needs to be small, and it needs to adhere to your skin pretty well. And typically when we're talking about that, either something you directly put onto your skim or something that can be tightly integrated with, the textile or any kind of, shoes, hats you're wearing, things that are integrated with those.

we also call wearables. And right now, typically for the researchers, we have two routes of going forward. One is the e-skin, which is basically epidermal electronics. and the other route being the e textile, me. Electronics that are tightly integrated with textiles, that are performing, functionalities that you typically see in, electronics.

[00:06:08] Mizter Rad: Okay, I see. so basically there is a, there's a discrepancy in what the consumers, the regular people in the market think of wearable electronics, which are these, I would say at the moment in the present time, bulky devices that you strap on your wrist or on your neck or on your ankle, and they make sure they give you some sort of KPIs.

But now researchers like yourself and your colleagues, you think of wearables. and I believe maybe this is, and maybe we can talk about this, the future of wearables: need to be more comfortable, need to be, maybe softer, smaller, and they need to adhere on the skin. And then you talk about two types of wearables, so to say, that are the e skin and the e textile.

Can you elaborate on this?

[00:07:07] Lu Yin: Yeah. So essentially, at least from my perspective, the purpose of wearables, is a new way of generating data and,getting more human to machine interactions. So in that regard, for the e-skin form factor, you are putting some discreet, integrated electronics. Think of a, like a patch or a bandaid that you can put on the surface of the skin and it has all the components on it for it to work.

So maybe you can do a wireless power transmission on the wireless device, with a coil printed around the bandaid, and it has a sensor on the bandaid that can, sense what whatever is happening on your wound. And, in addition, there needs a,needs to be a way. For you to get access to the data as well.

So if you're sensing something about wound, like the temperature or the pH change, you need to have a way of also getting access to that data. so that's the composition, basic compositions in wearable device, that it has a sensor, it has a power, it has a, central processing unit, typically a microcontroller, and it has a way of transmitting or displaying the data.

And the same thing goes for e-textile. But for e-textile, it's a concept that is more of a larger scale, system because, A shirt is definitely larger than a patch you put on to your skin. . And in that case you can, it will be a fully connected integrated system that you can adapt this kind of sensor, like an ECG sensor on the chest and maybe a sweat sensor on the armpit and some motion sensor, on the body.

So it's more of an interconnected system. And, it also have all those components we're talking about, including, a power source, a processing unit, all the sensors that generates the data and the way of,transmitting those data, to some something that allow you eventually to get access to that.

And, reversely also, maybe some, Sensor that can sense your interaction with the sensor. Think of, like a touch pad that, if you lay your finger on it or if you breathe on it, if you look at it, then there will be some interaction between you and the electronics. So that's, I don't know if that is, a good answer to your question.

[00:09:43] Mizter Rad: Yeah, absolutely. I get it. when you talk about, did you say ecg?

Yeah. what is that?

[00:09:50] Lu Yin: Basically it's, a signal about, Your heartbeat, right? That's some functions, that you, find on Apple Watch. basically measures the current, the, current that drives your heartbeat, and it can be measured epidermal by, measuring two points across your, heart, like from your left hand to your right hand, which is how the apple watch is doing it.

Or typically a halt monitor, which is, measuring, across your heart these kind of things. it's measuring just a electrical potential shift, when your heart beats, it's actually a contraction of the muscles, and then the contract is actually electrical signal that you can measure. So it's something people, can do nowadays that,you see very commonly on this wearable smart watch.

Okay. And, strap on, device as well.

[00:10:40] Mizter Rad: I understand that, and I wonder if the, complexity or one of the biggest complexities in what you're trying to build, that is, wearable technology that is more flexible, adaptable to the skin, that feels better, softer, smaller, and that it adheres onto the skin on, maybe on textile, since we are talking about smaller devices and maybe thinner, softer, flexible compared to an Apple watch, for example, where yeah, is the computing, what is the computing happening?

Because I feel like,the Apple Watch has enough room to maybe process some, has some computational power. but the, a patch, like a bandaid with the... that is very thin and dear to your skin. do, are we there yet? can a bandaid already compute something and show you some KPIs on, on, that are maybe related to what's happening in inside of your body?

[00:11:41] Lu Yin: Yeah. So the answer is, yes and no. it depends on, people's perspective. So I think the most, appropriate example, I'm going back to glucose sensing for people with diabetes, the CGM devices, those are very hardcore wearable devices that people has a very immediate and urgent need, to these devices considering people with type one and some with type two diabetes, they're using insulin and they need to measure what is in their blood glucose, what's their blood glucose level all the time.

So they wear that sort of wearable device that has a needle that sticks into their body. And, uh it gives you a continuous trend of how your glucose level is going up and then going down, which is a significant improvement compared to what were doing, which is pricking their finger and use a, blood glucometer with, sensor strips that you plug into the meter.

if you know what I'm talking about, those are not really easy to use and, not convenient at all. And for these people who are using insulin with diabetes, they need to, if they're pricking their finger at least four or five times a day, typically even more than that. otherwise if they don't know their glucose level, they, in, they put in a incorrect amount of insulin that could be really dangerous for them.

so these kind of device, nowadays you call them wearable, but they still have rigid components. They are being miniaturized, from something that were, previously maybe the size of an apple watch. now slowly going down to a size of a penny or at least a quarter a coin. and that kind of miniaturization is, made based on the feedback from the consumers that if it's too big, it's not really comfortable to wear.

And, And also by the progress of the minituarization of electronics, then, you can buy more chip that can do all these measurements, uh, previously maybe at few milliamp you to power this chip. Now, maybe with only a few hundred microamps you can power it. So if the power consumption of the chip goes down, then the battery you need for powering the chip, also the size of that goes down.

That's how miniaturization, takes place. So these kind of things are happening as we're speaking. Newer generations of CGM are coming out, although being still rigid and,but they're becoming less and less bulky and,being smaller and smaller. And as for something for like a bandaid, I think the reason I say yes and no is no, we're not there yet because, we can definitely make a sensor, on bandaid work.

But if you really wanted to operate, autonomously, like a consumer device that you can buy from a drug store and put that on you and expect it to work, it doesn't really work that way because, the sensor is already there. We can make sensor that works with that small size, but the problem is we also need to put in at least a microcontroller that takes a measurement and then transmit the data.

probably some antenna if you're using Bluetooth or fc, and that part can be easily manufactured, but also you need some battery or some kind of wireless power delivery scheme to, Power the chip. And that's the actual hold up about of the next generation wearable electronics that no one has been focusing on the, energy delivery or energy storage solution that has enough power, that works with existing, computer chips that do the measurement.

[00:15:31] Mizter Rad: Super interesting that you touched the power topic, because, I believe that as the demand of wearable electronics go up, it is clear to me, and I wanna know your opinion on this, that the demand of wearable power sources also go up. I believe earlier this year you wrote an article on the National Science Review where you talked about wearable energy systems.

What is wearable energy systems? What is this all about? Can you explain us a bit more?

[00:16:05] Lu Yin: Yeah, so that's extension of what I was just talking about, that for wearable device, In a minimal requirement, you need to have some energy storage device or energy delivery solution. So let's go back, right?

You have, let's assume a microcontroller that require, when it's operating one milli amp at three volt. so if you want to power this, you can buy a coin cell, from the store to power it. But then, the coin cell, it will be the limiting factor for the device and the coin cell itself you can say it's the, power system, really not being a system, just a power s energy storage solution for your system.

And if you want to remove that limitation, then you can put some NFC coil around your sensor and remove the battery. in that case, your NFC coil is the energy system. but when you, if you wanted to work, you need a wireless charger or have a phone scanning it,when it's working. So that, gives you a, worse user experience, imagining something, You can just wear and forget about it.

now you have to actually scan it every minute to get the data. even though it's, smaller and more flexible, the user experience is worse, right? And then people would think,why don't we, do a wirelessly charging battery? And then it goes a little bit more complex. the energy system on that it both has a wireless power delivery and also a battery. Also the charging regulation circuits. And those compose the all wearable energy system. And, now researchers are also looking to. energy harvesting from the human body. So instead of you act actually needing to think about recharging your device, what if the device can just harvest energy from your human, from the human body or it's surrounding environment?

So it's, this, so you have a battery within that's being discharged, and being charged at the same time. So that's the most complete picture we're thinking of that has all the components to make the device, even energy autonomous. And in that case, the energy harvesting, energy regulation, energy storage, all of those, compose that energy system for wearable device.

[00:18:34] Mizter Rad: Okay, I get it. So would you say that the... one of the ways of solving the gap between energy, demand and supply is to look at the body as the energy source.

[00:18:50] Lu Yin: Yeah. So there are several things I think, researchers are doing right now. so about the energy gap, I did mention in that review paper, we publish that typically nowadays, if you want to do these kind of energy autonomous wearable devices, the energy harvester typically operates at the order of few hundred, up to a few hundred, micro watt centimeter square, of energy harvest.

But the problem is that the energy demand of typical electronics are in order of a few milli watts, at least even going up to, a few hundred milli watts like Apple watch typically consume that much power. So, uh, that there is a significant mismatch because we are off by several orders of magnitude, imagining you have a, basically a pool of water and, you are draining water one end, you are pouring in water on the same end, on the other end, and you need to make sure the watch are going in, going out are around the same rate, right? You cannot having water going out tons per second, where you just have, some water dripping in few droplets per minute. in that case, this is never going to work, and that's what the mismatch I'm talking about and to really make this work then researchers are making, efforts both to reduce the power consumption of the electronics, as well as increasing the power input from these energy harvesters. And, I see that in the future, we need to meet in the middle, with reduced power consumption and increased power, input to eventually have a balanced, uh, uh, sort of, uh, having a equal balance sheet for the energy.

Okay, I see.

[00:20:48] Mizter Rad: I think you touched interesting topics here because, so from what I understand, what you're saying is: Researchers need or want, or would suggest that the electronic manufacturers or the battery producers think of creating devices that consume less energy. And at the same time, scientists or companies, the private sector should also look into somehow increasing the output of energy that, for example, you can harvest from your body.

But this is from a, from a, you know, researcher's point of view

what do you know the private sector or the commercial sector is doing regarding this topic?

[00:21:33] Lu Yin: Yeah, so in a different, review that we wrote, I think also around the same time,we propose our vision of what's going to happen the following few years.

obviously the sensing part, the part that's generating the data, if we are not considering, making the battery or the energy harvesting part, flexible, at least the sensor part has been ready for quite some time, and that's what we are seeing, basically that the sensor are becoming, more wearable and more miniaturized and, consuming less and less power.

So that's the part, I think even in the commercial,efforts to make this a real thing rather than just publication things are happening. There are more and more wearable sensors being produced, and these wearable sensors, have, both good, uh, four factors in terms of flexibility, wearability, and also, these wearable devices are being plexed.

So instead of just measuring one thing only, most of the device nowadays are starting to measure more and more things on the same device. So basically occupying the same space, while doing more things or doing the same thing, but occupying less space. And I think in the future few years, even going towards the next decade, you are going to see more and more innovation in this front.

And what's the bottleneck for the next generation? Those all flexible things coming out? I think it's the battery because, it's something that you cannot buy with money nowadays. a really good high performance flexible battery, and the best flexible battery. The last time I look at it, there are only a few, company are making it and they're on the other magnitude of few, milliamp power centimeter square.

So that means it's probably a hundred times lower energy density, compared to the coin cells. So it makes no sense for most of the OEMs. The, electronic manufacturers, to ask their engineers to design a new product based on these less, these low power or large area battery, that with the only benefit of making a device a little bit more flexible, no one wants to make that compromise.

So the next big thing needs to happen is to have a battery, that's not only flexible, but also can deliver similar performance as, these commercial coin cell batter or even pouch, lithium ion batteries. And that's also something I was working on in the past. We had some work, developing high performance battery, and now this, technology has been licensed by, companies who are trying to commercialize these.

So the battery will be the next step, to enable other things that are not necessarily energy autonomous, but more flexible and more integrated. And with the last po piece of the puzzle being the energy harvesting that's gonna happen, later than when the battery is becoming available, that eventually the energy system will becoming, will become autonomous.

You will have trickle charge from your, uh, movement, from your perspiration, from the surrounding environment, like the temperature gradient or even from the sunlight, from moisture that you can just harvest energy and not having to worry about replacing the battery or recharging the battery. But that will be a few more steps away from what we have right now.

[00:25:16] Mizter Rad: Okay. Let's talk about. Harvesting energy. and let's start with the basics. what is harvesting energy and how does it relate to the battery? Cause I, I feel that the battery is a problem and the OEMs,the manufacturers of electronics, don't wanna go the rabbit hole of creating products, around this small, flexible batteries, basically because they're not good enough for, the kind of devices that they're building.

So now you come in, researching on how to harvest energy from your own body and at the same time how to create a battery that is thin, flat, and more efficient. Is that correct or am I missing something?

[00:26:04] Lu Yin: Yeah, that, that is correct. in terms of creating batteries, essentially, There's a mismatch, as I mentioned, between the energy input you get from all these harvesters, which means in the order of, micro wat, and then the power demand for these, typical, microcontroller chips that, typically requires few milliwatt to even hundreds of milli watts.

to make a battery that really, worth the attention of all the electrical engineers from the big oem, you would need to make a battery that's good enough for the existing chips first, disregarding what's happening about the, wearable energy harvesters first. if they're consuming few Milli wat and you wanted to work for two days and your battery better be small, flexible, but also has the energy of, tens of milliwatt hour of, energy stored. so that's, going to, be the most difficult part because if you want to make things flexible and small, you're making a lot of sacrifice in terms of the performance. So it would be really difficult to make batteries that are equally powerful as the rigid counterparts, and being able to power these high power electronics.

and for the energy harvesting part, essentially, there are so many things we can do and there's so much potential. our body is outputting tens of watts just by sitting around and not doing anything. Our body's emitting heat. If you're walking around, if you're jogging, if you're running, you're outputting few hundred wa of power.

Imagining just taking 0.1% of that power to use, that's enough to power a lot of electronics you have on your body. the problem is being able to create a, efficient way of harvesting these mechanical energy,to have it, having high conversion efficiency, since basically we, we cannot create the energy.

Energy harvesters are made to convert energy from one, form into a different form.

[00:28:17] Mizter Rad: okay. Sorry. let me, sorry, sorry to jump in. Let me interrupt you there because, okay, so you're saying you, youyou can harvest, which means basically means you can grow in a way, you can, collect, transform energy from your body, sweat, from your body heat, from your movement, and transform that into electricity that goes into your wearables, let's say your watch, right?

Yeah. the problem is that, what's a problem basically do, is it the battery or, I'm trying to understand here, or is it more than that? or do we actually need a battery? Because I'm thinking if you're always sweating or if you're always producing heat, why? Why do you need a battery anyways?

[00:28:56] Lu Yin: Yeah, exactly. So I guess the question is twofold. One is what's the problem? And two is why do you need the battery? So the problem being that the existing, energy harvesters are not, efficient enough. So there's one concept we're talking about is energy return on investments. basically is, towards wearables.

It's about the energy you put towards, harvesting and the actual, energy you get out of it. So imagining you are running, your body is actually outputting few hundred watts of power. But, from a, mechanical energy harvester, like those triple electric generator, the harvest energy from friction, it can generate up to a few milli wat of power.

so really if you look at the efficiency, it's horrible, right? S you. Getting maybe 0.01, even 0.001% of power from the, movement. It doesn't make sense and no one wants to do that. So an important thing, the problem being that, we need to make this number higher in terms of other magnitudes, not only by a few times, but tens or hundreds of times.

and also maybe try to harvest energy from more passive activities, which is what we were doing, from sweat, right? so imagine if you don't have to do anything to harvest energy, then you really don't have to think about the return on investment because you're not investing anything. So that's, one of the work, I think, we are talking about today about harvesting sweat from the fingertip, which solves a problem, right?

that you don't have to actively exercise to get sweat from your fingertip because the finger is actually very unique compared to other locations of the body that you are able to have sweat generated there. regardless of what you're doing, even if you're sleeping or you're eating, you're running, or you're just sitting and doing nothing, your fingers, emitting sweat all the time.

And that's the reason you leave fingerprints everywhere. Uh, it's sort of a function by evolution that allows you to grab things better because the sweat, give you a better friction. When you are holding things and we can actually use the small amount sweat. It has a lot of chemicals within that can be, used in chemical reaction.

And then we use enzyme to break down, the components within the sweat to generate energy, or I shouldn't say generate energy, but to convert the chemical energy into electrical energy. so that's a sort of thing that we're trying to improve in terms of practicality. We don't want to ask people to run for a mile to charge their wearables.

We want the people to have minimal amount of input, to, to harvest the maximum amount of power. And that's the problem we are trying to address right now.

[00:31:51] Mizter Rad: That's beautiful. That's beautiful. And yeah, tell me.

[00:31:56] Lu Yin: Yeah, the thing you mentioned about batteries, essentially that's, from some point it's going from just a power source.

Then if you're integrating it with energy harvesters, then it transforms into a energy regulation part. So, uh, in a analogy. imagine you have a house connected to, solar panels, right? what if you want to use the solar panels to light up the lights you have in the room? If you don't have a battery pan, if you don't have a battery group in your house, that means you can only turn on the lights during the day.

In the night when the sun goes down, your lights also goes off. It doesn't make sense. So that's where the battery comes into play, that the battery is there to regulate the energy, to like how you're saving up money, you're saving up energy so you can use it when you need to use it. And that's the purpose of adding the battery in these wearable devices.

[00:32:56] Mizter Rad: Okay, I see. I see. that's interesting that you talk about that and you talk about the, or you give the example of solar energy. and the solar panels. I'm trying to wrap my, he head around a thought that I had, two days ago when I was preparing for this conversation. in a way I feel, and this is just a thought I have, and maybe, you can jump on board or not and think with me, but in a way I feel that you work whether you want it or not, it's almost like highlighting the idea or importance of using energy as a currency, in this case, energy, and the energy you produce yourself can be used if you over produce, let's say cuz you sweat more than the guy behind you or next to you. In a way you have excess energy. and of course, you can say, it's never enough.

But, with your own body, with your own InBody processes, with mechanisms happening within you 24 7, you can think or imagine a kind of decentralized energy, harvesting system that depends only on you and probably what you eat on, how healthy you are, how, you know how well your body, your system functions.

And I wonder if this, in a way, what we are creating here will eventually create a, an electric grid of human bodies,like an energy system, electric grid of humans that generate enough electricity to power up certain. I don't know, even neighborhoods, at some point, or maybe this is too crazy, but what that will also mean, and this is an assumption, is that maybe the healthier you keep your body, the better energy you'll be able to contribute to that human body's electric grid and eventually talking about currency, the more you will contribute to that grid, the more you get paid for it. And this to me seems like a win-win situation for everyone. But maybe I'm going too much ahead in the future and I wanted to share that thought with you and wanted to, um, see what you think about this?

[00:35:09] Lu Yin: Yeah. I think you're absolutely right about the concept and also about your very ahead of its time.

essentially I, in our research group, we have proposed the idea of where will microgrid. So it is a decentralized energy grid that runs on your body, to harvest energy from all your movements, your activity, So you have sweat energy from basically biochemical energy. You have, biomechanical energy from all your movements.

You have probably thermal energy from your body heat, and also, you probably would, benefit from solar energy if you are walking outside and then the sun shines on you, you have wearable solar panels on you. All of these, can make your wearable device a little bit more resilient in a sense that it can be off grid for a long time without worrying about recharging.

And of course, the eventual goal is to have everything,can operate completely off grid. imagining you bought a house and then instead of relying on the city grid, you have enough solar panel in your house that you never have to worry about. Buying electricity from your, electricity supplier and even being able to connect to the grid and feedback electricity, and you can actually sell those, actual,what hour of, power to the grid when they need it.

and that's what's happening in a microgrid, city level. Microgrids nowadays that people or companies or factories, they're using renewable energy, they're storing that, and you can even have the option to feed it back to the main grid. And that's the same thing we want to see with the wearable electronics that at least, in the, near future, we should be able to have the ability to, do independent grid that, you don't have to worry about recharging all your wearable devices, even like your Apple watch can power itself.

That would be great, right? And, that would, make the user experience much better as well. but it will be still quite far away before you can harvest significant amount of energy to actually recharge a city grid. Because we're talking about Watt hour, even up to a kilowatt hour. Mega Watt hour level.

We are still not we are far from that. Yeah. But there's something I think worth investigating or of interest is now more and more wearable sensors and the telemedicine, the age of telemedicine is coming with the covid, right? People are being more and more aware of their health and having, developed a way to decentralize, healthcare and instead of, selling your energy from your sweat. what about the en, what about the data generated from all your wearables? Those can be used for the greater goods of the entire human kind, that scientists can find more about how your daily activity affects your health. And all of those data also have values, just like how you post everything on the internet, how you write an article on a blog post.

All of these information about your body from all these sensors also has values. And these values, can be calculated. And you are, instead of feeding back energy, you're feeding back information. and that can be a part of an information grid that we're talking about that we can establish, within a person and also among people.

[00:38:51] Mizter Rad: Absolutely. Um, I wanna actually, you touch telemedicine and I wanna understand a bit more about your work on monitoring our health with the use of wearable electronic devices, like the ones you are working on. and I believe you also use artificial intelligence in this real. Can you tell us a bit more about this?

[00:39:17] Lu Yin: Yeah, so our lab has been working primarily on, biosensors or electrochemical sensors. So basically we are measuring the concentration of different biomarkers that goes on in your different biofluid, including blood, including saliva, tears, sweat, interstitial fluids, urine. All of these biofluid that you have contains tons of information that's about you.

There's just lack of a good way of measuring these things semi automatically or automatically and continuously. And that's what we are doing now, trying to make, devices more wearable and miniaturized. So you can put a device on you to continuously generate data, and then you can link that with your other activities.

So imagine that you have just ate a banana and you can see that your glucose level went up and also your blood pressure went down or your heart rate went up. Things like these, right? and different people may react differently to different, habits. Imagine if you just drink a cup of coffee. Some people react really well to caffeine, some people don't.

And you can use these kind of trend to do analysis. to find what is really coffee doing to people there. You probably can find thousands of papers, some saying coffee is good for you. Some saying coffee is bad for. And in this way, you can really collect more and more data, in a way that, people weren't imagining before and making better conclusion, not only a grand sum of all the trends, but also a personalized guidance based on you.

So some people, it's good for them to drink coffee, it makes them more aware, makes them more healthy, and. For some people it's a bad idea to drink coffee because it makes their heart rate goes up, their blood pressure goes up, and all of these analysis needs to, it has tons of data generated that can be analyzed by AI to find, the trends that people weren't able to find before.

And all of these data are generated from all of these new sensors. so you are basically getting more and more data points from more and more sensors, and you can use AI to translate those data into actionable items, into, more comprehensible, trends that can be personalized, can be summarized for the entire human race.

you can do whatever you want with those data, assuming you have a good source of data and you have a best way of analyzing those data

[00:42:06] Mizter Rad: is being healthy in any way a determining factor on the quality of the data that you can get?

[00:42:14] Lu Yin: No.

[00:42:15] Mizter Rad: What I mean with that is if you're a healthier person, do you output better data because your organism is cleaner or not, doesn't matter because in any case, you're, or you are analyzing everything or how is that working?

[00:42:27] Lu Yin: In my view, it doesn't really matter. Think about what clinical trials, that's what you need to do to get medical devices and drugs through the market. No one's going to get a drug, or a study, a drug through the FDA or getting a study published without studying the patients. So I think there will be a lot great insight you get from monitoring people with specific health problem.

the most familiar topic I had is definitely with people with diabetes. If you want to know, say eating brown rice, it's better than eating white rice for you. You might not be able to see much trend for people who have very healthy metabolism. But if you do the same study on people with diabetes or people who has, I don't know, irritable bowel syndrome or people who have different allergies to grain, you are more likely to find better insights in that regard.

So I would say that depending on what kind of, information you're trying to find, if you want to see say what kind of exercise is most useful, if you want to get fit, you probably want to study a bunch of, athletes. vice versa, if you want to see what's causing you to be less healthy, then you probably want to study those who are less healthy.

So I think everyone can generate data that's useful for someone.

[00:43:52] Mizter Rad: And when it comes to sweat specifically, cuz you said that everyone, of course everyone sweats, but I am assuming the composition of the sweat is different, from a person to person. does it matter the kind of sweat, the quality of sweat you have in order to, harvest energy?

[00:44:09] Lu Yin: Oh, yeah. it really depends on the kind of chemistry we're working with. in this work that we harvest energy from the fingertip, we actually use the latic acid or the lactate, in the sweat. So that typically is higher for people who exercise, less, but has a high passive sweat rate so that, if your body cannot keep up with your metabolism, The anaerobic, breakdown of glucose, generates, more lactate.

And in that case, you are giving more fuels, essentially. And based on some of our previous study, studies, actually, people that are less fit, they can generate more lactate. and more lactate means you get higher power. So actually people that are less, fit, can give more power from their sweat.

and for people, if we're making those instead of using lactate, now we use glucose as the fuel, then you probably find the best, subject to generate energy to be those who have diabetes, especially type two diabetes, because their glucose level are higher than,than usual. So it really depends on the kind of chemistry we're using.

[00:45:25] Mizter Rad: So do you imagine something like a, like a,like a humanoid that is injected with glucose, in order to produce energy from that, or not produced, but harvest energy from that, instead of, harvesting from a human body, because of course you don't want people to have high glucose levels cuz it, it has a lot of,health consequences, but you could inject a humanoid or something with, with that or any other object that could, somehow replicate the function of the body.

I'm not going a little bit too much in the tangent here, but. . is this a valid thought or is this just too much?

[00:46:08] Lu Yin: Oh, I think it's a valid thought. I think still, chem chemists have a far, a long way to, to walk, from a robot that can directly process food into energy instead of nowadays what they're doing.

At least you. Burn gasoline or having, hydrogen fuel cell to do that. basically, in terms of our, energy harvesters, it's still a fuel cell. It's just a lactate fuel cell or a glucose fuel cell that's doing the work. and there has been other fuel cells that's being studied, like methanol fuel cell or ethanol fuel cell.

So I don't, if you pour a beer into the robot, you can make it work. that's totally possible. but the human is a really efficient machine in terms of breaking down food and generating energy from that, that, it's totally possible, but we still have a, long way to go.

[00:47:02] Mizter Rad: I definitely agree that the human is a, is a, is a very powerful machine and with the capacity of, as you explain powering up devices, hopefully in the future, more and more. when you look at the future, when you imagine this technology evolving in the next 10, 20, 50 years, which direction would you think us humans would go into?

Do you think we will be more into generating this organic energy systems like using the sweat of your body or other body fluids or maybe heat to power our up devices? Or do you think we will use external energy systems, sort of plug and play where you can maybe put your finger to wirelessly, uh, charge your wearables, from the normal traditional electric grid.

Or do you think it's a combination of both?

[00:47:59] Lu Yin: I think both are possible. So considering the development of things that are going on right now, we have, phones that can be charged faster and faster, right? It used to take overnight to charge. Now with the most, advanced Android phone, I've seen like one 20 wat charger even, which is crazy.

You can charge your phone battery, within 10 minutes. and those things are equally important for, uh, you know, uh, EVs and, uh, different kind of tools outside wearable devices. At the same time, I think, I do see a great future for wearable devices and, to have them operating autonomously because it has a very, significant benefit of, more superior user experience imagining, not having to think about recharging something at all.

Right. If you can operate autonomously just based on itself, assuming that doesn't add extra cost, and there will be manufacturers to make this, at the same cost or even at lower cost compared to those that requires charging. It would be something super attractive, imagine you have a bandaid that can sense your wound healing speed, but also the bandaid is powered by all the,by all the blood and all the biofluid coming out of your wound.

But that would be very attractive instead of thinking about charging the bandaid, even if, it takes just five seconds to charge, Still something that operates by itself is very attractive.

[00:49:32] Mizter Rad: Oh man. I think we are going into transhumanism here, and I think this is fantastic because when I was

preparing for this conversation, I thought, it would be interesting to know what Lu thinks about this human machine interaction and how it will be evolving in the next 10 years. Do you think will be,more... how much of a human we will keep and how much of a machine will we become?

[00:50:01] Lu Yin: I mean, I just saw the news about Neurolink and, Elon Musk are trying to make, disabled people walk and you can control your limbs with your thoughts.

Previously I even saw e-tex head companies that gives, um, electrical stimulation to muscles to help the disabled people move their, limbs more easily.

all of these are used to be a sci-fi and more and more close to possibilities. so I think definitely, People would want to be still human. I think that's something that's innate our mind, that we would not like to change everything about ourselves, but it really depends on how we define ourselves as human.

So I'm getting a little bit too meta here, but, essentially, if you think what is you, is only based on what you're thinking, then you probably are fine with replacing your limp into a, uh, electrical limp if it gives you higher power. Or if you want to replace your mind, if you want to just upload your mind, to a metaverse, I would have seriously a serious concern about these.

Of course. There will be a lot of regulations that are impeding these and there's so much ethical hazard, that are preventing these to happen. Think about cloning people. The technology we have nowadays,we're probably already 10, 20 years, ahead, that we can already clone people and we are not doing that to harvest organs.

the reason it's very clear is about the ethics, right? And the ethics is more something more important in technology that defines us into a society. in, in that term that in a sense that you face a lot of resistance. That it's not the technology at that point anymore. It's about politics. It's about how people are thinking, it's about religion that are preventing these kind of things to happen.

[00:52:00] Mizter Rad: That's interesting that you touched that topic because,one of the things I get most asked is when I go and talk in schools to young people is: what should I study? What should I focus my energy on?

What are these trends that are happening on a macro level in the world that I should be looking at so that in the future I can get a good job, get good money and be happy?. And so a lot of people think the answer is becoming an engineer or knowing how to code and maybe being very specialized on a field like, biochemists becoming a biochemist specialized in, like we were talking today, harvesting energy from living beings.

but what you said is super interesting because. All these advancements in technology will also bring a need for humans to be more human in a way, or keep the humanity alive. And therefore we need more sociologists, we need more anthropologists, we need more lawyers. And yeah, I think that's super interesting.

Would you agree with me or what are your thoughts on this? What would you tell the kids to study? Basically .

[00:53:22] Lu Yin: Yeah. I definitely, I'm on the side definitely for scientists. I think the world needs more scientists, needs more engineer who are down to do things, but if the world is full of engineers, the society will collapse, faster than you can imagine.

I definitely think that, if you are doing things, with the mindset that you want to make, to improve the world, you want to make the world a better place. No matter what you are doing, you're, I think it is worth doing. some people, their really, their philosophy is to do down to earth stuff, but like me, I'm engineering trained.

I'm not inventing battery chemistry, I'm not inventing, these fuel cells. I'm not inventing enzymes. I'm not inventing sensors. I'm merely, using my knowledge to bring these, principles into something more, realistic into something you can see, you can touch, you can use. and there are other type of people. They are really focused on the concepts. They are more of, not engineers, but scientists. They, and I guess one of the example comes to my mind like, if you want to study hi, expose on. What does that do to human race? do you, can you buy a, an ounce of hipo on tomorrow? Would that feed the children in Africa?

If you ask these kind of questions, you're trying to invalidate other people's effort. and I think it doesn't really works that way, that people needs to work on, things that you need to see change immediately. There needs to be these, visionaires that are just have their mindset into something so abstract, that those are the core of human race, that we were able to make things abstract.

And that is make us, uh, establish the concept of society. Uh, so these kind of things are not practical as we see it, but that's actually what makes human, human. And I, although I am not that type of people, I respect them a lot for art, for being artists, for being scientists that studies things that, that are not going to be commercializing a million year.

Right. These are the things that actually makes human, human, and they're also essential part, of the, of the entire society.

[00:55:50] Mizter Rad: Well put, well put, I believe that there needs, to be a balance and as you said, it's not only engineers that we need, but also people that dare to think different.

And even if there is no commercial use or for their thought, they just bring them up to the market because that's what makes us human. That's what makes us an incredible specie. And with that, Lu, I would like to close. I'm very happy and grateful now that we can, that we managed to meet and to talk and to have this space.

I think it went smooth. I'm very happy about it and I'm also very happy that I learned from you quite a lot, and I hope my audience also has a good learning experience after listening to this conversation. Lu, what, where can people know more about you? What can you share in your last words with them?

[00:56:44] Lu Yin: Yeah. Essentially, I'm still a researcher, so if you're interested in finding more about our research, actually a lot of our work is, being, publicized with, media press work, so you can search uses. The Nanoengineering department, there are tons of great work being produced every day, every month.

even just today, we publish a new work of a, capsule, that, can be ingestible to sense glucose. And the capsule itself is self-powered, so the glucose give you the signal and the power at the same time. keep an eye on what's going on in terms of science, and engineering. And, uh, also, if you're interested in talking with me, you can find me on LinkedIn, and, you send me a message.

You can find me here, at Twitter as well if you want to discuss more, any collaborations, any discussions you want to have, any career device if I'm ever able to offer. so yeah, those are my last words, but thank you very much for, inviting me for this talk.

[00:57:48] Mizter Rad: Thank you Lu, and have a wonderful time in Boston. See you next time.

[00:57:53] Lu Yin: Yeah, thank you.

[00:57:53] Mizter Rad: Have a wonderful day. Chao, Chao.