WEBVTT 00:00:01.173 --> 00:00:03.032 So, I love making tools 00:00:03.032 --> 00:00:05.035 and sharing them with people. 00:00:05.357 --> 00:00:06.746 I remember as a child, 00:00:06.746 --> 00:00:10.038 my first tool I built was actually a microscope 00:00:10.038 --> 00:00:14.079 that I built by stealing lenses from my brother's eyeglasses. 00:00:14.385 --> 00:00:15.954 He wasn't that thrilled. 00:00:16.195 --> 00:00:18.552 But maybe because of that momement, 00:00:18.552 --> 00:00:19.690 30 years later, 00:00:19.690 --> 00:00:21.714 I'm still making microscopes. 00:00:22.415 --> 00:00:25.986 And the reason I built these tools is for moments like this. NOTE Paragraph 00:00:27.560 --> 00:00:30.003 (Video) I have black things in my hair -- NOTE Paragraph 00:00:30.003 --> 00:00:32.278 MP: This is a school in [the Bay Area.] 00:00:32.864 --> 00:00:37.542 The living world far supersedes our imagination 00:00:37.542 --> 00:00:39.532 of how things actually work. NOTE Paragraph 00:00:39.532 --> 00:00:41.983 (Video) Oh my God! NOTE Paragraph 00:00:43.773 --> 00:00:44.992 MP: Right ... 00:00:44.992 --> 00:00:46.599 "Oh my God!" 00:00:46.788 --> 00:00:50.320 I hadn't realized this would be such a universal phrase. 00:00:51.195 --> 00:00:53.148 Over the last two years, 00:00:53.148 --> 00:00:54.226 in my lab, 00:00:54.226 --> 00:00:56.513 we built 50,000 Foldscopes, 00:00:56.513 --> 00:00:59.235 and shipped them to 130 countries in the world 00:00:59.235 --> 00:01:02.082 at no cost to the kids we sent them to. 00:01:02.397 --> 00:01:03.759 This year alone, 00:01:03.759 --> 00:01:05.748 with the support of our community, 00:01:05.748 --> 00:01:09.852 we are planning to ship one million microscopes to kids around the world. 00:01:10.114 --> 00:01:11.558 What does that do? 00:01:11.707 --> 00:01:15.601 It creates an inspiring community of people around the world, 00:01:15.601 --> 00:01:17.296 learning and teaching each other, 00:01:17.296 --> 00:01:20.989 from Kenya to Kampala to Kathmandu to Kansas. 00:01:21.329 --> 00:01:23.909 And one of the phenomenal things that I love about this 00:01:23.909 --> 00:01:25.833 is the sense of community. 00:01:26.050 --> 00:01:27.375 There is a kid in Nicaragua 00:01:27.375 --> 00:01:31.725 teaching others how to identify mosquito species that carry dengue 00:01:31.725 --> 00:01:34.166 by looking at the larvae under a microscope. 00:01:34.166 --> 00:01:36.737 There is a pharmacologist who came up with a new way 00:01:36.737 --> 00:01:38.980 to detect fake drugs anywhere. 00:01:39.451 --> 00:01:41.643 There is a girl who wondered, 00:01:41.643 --> 00:01:43.495 how does glitter actually work? 00:01:43.495 --> 00:01:47.486 And discovered the physics of crystal information in glitter. 00:01:47.825 --> 00:01:49.342 There is an Argentinian doctor 00:01:49.342 --> 00:01:53.417 who's trying to do field cervical cancer screening with this tool. 00:01:53.787 --> 00:01:57.548 And yours very truly found a species of flea 00:01:57.548 --> 00:02:02.618 that was dug inside my heel in my foot one-centimenter deep. NOTE Paragraph 00:02:03.448 --> 00:02:08.325 Now, you might think of these as anomalies, 00:02:08.325 --> 00:02:10.422 but there is a method to this madness. 00:02:10.705 --> 00:02:12.765 I call this frugal science. 00:02:13.006 --> 00:02:18.725 The idea of sharing experience of science and not just the information. 00:02:19.123 --> 00:02:20.471 Remind you, 00:02:20.471 --> 00:02:22.578 there are a billion people on this planet 00:02:22.578 --> 00:02:25.116 who live with absolutely no infrastructure: 00:02:25.116 --> 00:02:26.753 no roads, 00:02:26.753 --> 00:02:28.158 no electricity, 00:02:28.158 --> 00:02:30.993 and thus, no health care. 00:02:31.262 --> 00:02:35.498 Also there a billion kids on this planet that live in poverty. 00:02:35.825 --> 00:02:37.494 How are we supposed to inspire them 00:02:37.494 --> 00:02:39.955 for the next generation of solution makers? 00:02:40.304 --> 00:02:43.075 There are health care workers that we put on the line 00:02:43.075 --> 00:02:45.016 to fight for infectious diseases, 00:02:45.016 --> 00:02:49.473 to protect us with absolutely bare-minimum tools and resources. NOTE Paragraph 00:02:50.656 --> 00:02:52.398 So as a lab at Stanford, 00:02:52.398 --> 00:02:56.358 I think of this from a context of frugal sciecnce 00:02:56.358 --> 00:02:58.642 and building solutions for these communities. 00:02:58.963 --> 00:03:03.545 Often we think about being able to do diagnosis under a tree, off-grid. 00:03:03.880 --> 00:03:06.753 I'll tell you two examples today of new tools. 00:03:06.753 --> 00:03:08.764 One of them starts in Uganda. 00:03:08.989 --> 00:03:10.425 In 2013, 00:03:10.425 --> 00:03:14.494 on a fieldtrip to detect schistosomiasis with Foldscopes, 00:03:14.494 --> 00:03:16.847 I made a minor observation. 00:03:17.147 --> 00:03:18.747 In a clinic, 00:03:18.747 --> 00:03:20.200 in a far, remote area, 00:03:20.200 --> 00:03:24.041 I saw a centrifuge being used as a doorstop. 00:03:24.264 --> 00:03:26.555 I mean quite literally the doorstop. 00:03:26.757 --> 00:03:28.445 And I asked them and they said, 00:03:28.445 --> 00:03:30.495 "Oh, we don't actually have electricity, 00:03:30.495 --> 00:03:34.131 so this piece of junk is good as a doorstop." 00:03:34.913 --> 00:03:35.910 Centrifuges, 00:03:35.910 --> 00:03:37.465 for some of you who don't know, 00:03:37.465 --> 00:03:40.712 are the pinnacle tool to be able to do sample processing. 00:03:40.712 --> 00:03:43.477 You separate components of blood or body fluids 00:03:43.477 --> 00:03:46.197 to be able to detect and identify pathogens. 00:03:46.563 --> 00:03:49.420 But centrifuges are bulky, expensive -- 00:03:49.420 --> 00:03:51.751 costs around 1,000 dollars -- 00:03:51.751 --> 00:03:53.760 and really hard to carry out in the field, 00:03:53.760 --> 00:03:56.066 and of course, they don't work without power. 00:03:56.066 --> 00:03:57.399 Sound familiar? 00:03:57.691 --> 00:04:00.354 So we started thinking about solving this problem, 00:04:00.354 --> 00:04:01.927 and I came back -- 00:04:01.927 --> 00:04:03.634 kept thinking about toys. NOTE Paragraph 00:04:03.914 --> 00:04:06.260 Now ... 00:04:06.260 --> 00:04:08.264 I have a few with me here. 00:04:08.264 --> 00:04:10.324 I first started with yo-yos ... 00:04:10.324 --> 00:04:12.763 and I'm a terrible yo-yo thrower. 00:04:12.979 --> 00:04:14.753 Because these objects spin, 00:04:14.753 --> 00:04:15.750 we wondered, 00:04:15.750 --> 00:04:18.087 could we actually use the physics of these objects 00:04:18.087 --> 00:04:20.294 to be able to build centrifuges? NOTE Paragraph 00:04:21.329 --> 00:04:23.819 This was possibly the worst throw I could make. NOTE Paragraph 00:04:24.587 --> 00:04:26.095 But you might start realizing, 00:04:26.095 --> 00:04:29.024 if you start exploring the [safe space] of toys -- 00:04:29.024 --> 00:04:31.652 we tried these spinning tops, 00:04:31.652 --> 00:04:33.662 and then in the lab, 00:04:33.662 --> 00:04:35.689 we stumbled upon this wonder. 00:04:35.971 --> 00:04:37.326 It's the Whirligig, 00:04:37.326 --> 00:04:38.394 or a Buzzer, 00:04:38.394 --> 00:04:39.469 or a [Roudrun.] 00:04:39.469 --> 00:04:42.017 A couple of strings and a little disk, 00:04:42.017 --> 00:04:44.349 and if I push, it spins. 00:04:44.557 --> 00:04:46.853 How many of you have played with this as a kid? 00:04:46.853 --> 00:04:48.724 This is called a button-on-a-string. 00:04:48.724 --> 00:04:50.461 OK, maybe 50 percent of you. 00:04:50.461 --> 00:04:52.042 What you didn't realize -- 00:04:52.042 --> 00:04:54.238 that this little object 00:04:54.238 --> 00:04:58.751 is the oldest toy in the history of mankind. 00:04:59.007 --> 00:05:00.676 5,000 years ago --- 00:05:00.676 --> 00:05:04.375 we have found relics of this object hidden around on our planet. 00:05:05.223 --> 00:05:08.985 Now the irony is we actually don't understand 00:05:08.985 --> 00:05:10.945 how this little thing works. 00:05:10.945 --> 00:05:12.651 That's when I get excited. NOTE Paragraph 00:05:12.964 --> 00:05:15.122 So we got back to work, 00:05:15.122 --> 00:05:16.912 wrote down a couple of equations. 00:05:17.223 --> 00:05:20.559 If you take the input torque that you put in, 00:05:20.559 --> 00:05:22.813 you take the drag on this disc, 00:05:22.813 --> 00:05:24.741 and the twist drag on these strings, 00:05:24.741 --> 00:05:27.153 you should be able to mathematically solve this. 00:05:27.153 --> 00:05:29.661 This is not the only equation in my talk. 00:05:29.971 --> 00:05:31.826 10 pages of math later, 00:05:31.826 --> 00:05:34.704 we could actually write down the complete analytical solution 00:05:34.704 --> 00:05:36.218 for this dynamic system. 00:05:36.563 --> 00:05:40.000 And out comes what we call Paperfuge. 00:05:40.197 --> 00:05:41.498 That's my postdoc, 00:05:41.498 --> 00:05:42.591 Saad Bhamla, 00:05:42.591 --> 00:05:44.260 who's the co-inventor of Paperfuge. 00:05:44.260 --> 00:05:45.256 And to the left, 00:05:45.256 --> 00:05:48.107 you see all the centrifuges that we are trying to replace. NOTE Paragraph 00:05:48.107 --> 00:05:53.042 This little object that you see right here 00:05:53.042 --> 00:05:56.175 is a disc, a couple of strings and a handle. 00:05:56.470 --> 00:05:58.100 And then I spin. 00:05:58.100 --> 00:05:59.102 And I push, 00:05:59.102 --> 00:06:00.195 it starts to spin. 00:06:00.195 --> 00:06:03.292 Now, when you realize, 00:06:03.292 --> 00:06:05.715 when you do the math, 00:06:05.715 --> 00:06:08.228 when we calculate the rpm for this object, 00:06:08.228 --> 00:06:12.816 mathematically we should be able to go all the way to a million rpm. 00:06:13.011 --> 00:06:15.107 Now there is a little twist in human anatomy, 00:06:15.107 --> 00:06:18.106 because the resident frequency of this object is about 10 hertz, 00:06:18.106 --> 00:06:19.493 and if you ever played piano, 00:06:19.493 --> 00:06:21.697 you can't go higher than two or three hertz. 00:06:22.106 --> 00:06:25.613 The maximum speed we've been able to achieve with this object 00:06:25.613 --> 00:06:27.565 is not 10,000 rpm, 00:06:27.565 --> 00:06:29.269 not 50,000 rpm -- 00:06:29.269 --> 00:06:30.839 120,000 rpm. 00:06:31.107 --> 00:06:33.697 That's equal to 30,000 g-forces. 00:06:33.934 --> 00:06:37.164 If I was to stick you right here and have it spin, 00:06:37.164 --> 00:06:40.141 you would think about the types of forces you would experience. NOTE Paragraph 00:06:40.441 --> 00:06:45.395 One of the factors of a tool like this is to be able to do diagnosis with this. 00:06:45.777 --> 00:06:49.243 So I'm going to do a quick demo here. 00:06:50.514 --> 00:06:54.061 So this is a moment where I'm going to make a little fingerprint. 00:06:54.061 --> 00:06:56.122 A tiny drop of blood is going to come out, 00:06:56.122 --> 00:06:57.299 if you don't like blood, 00:06:57.299 --> 00:06:58.712 you don't have to look at it. 00:06:59.092 --> 00:07:00.539 Here is a little lancet. 00:07:00.539 --> 00:07:02.432 These lancets are available everywhere, 00:07:02.432 --> 00:07:03.819 completely passive. 00:07:03.819 --> 00:07:09.116 And if I've had breakfast today ... 00:07:10.191 --> 00:07:11.677 That didn't hurt at all. 00:07:12.153 --> 00:07:15.836 OK, I take a little capillary with a drop of blood -- 00:07:15.836 --> 00:07:18.064 now this drop of blood has answers, 00:07:18.064 --> 00:07:19.687 that's why I'm interested in it. 00:07:19.910 --> 00:07:23.119 It might actually tell me whether I have malaria right now or not. 00:07:23.489 --> 00:07:25.547 I take a little capillary, 00:07:25.547 --> 00:07:27.765 and you see it starts leaking in. 00:07:28.072 --> 00:07:30.772 I'm going to draw a little more blood. 00:07:32.782 --> 00:07:35.025 And that's good enough for right now. 00:07:35.519 --> 00:07:39.924 Now, I just seal this capillary by putting it in clay. 00:07:43.588 --> 00:07:45.659 And now that's sealed the sample. 00:07:45.987 --> 00:07:48.139 We're going to take the sample, 00:07:48.139 --> 00:07:50.357 mount it on Paperfuge. 00:07:57.275 --> 00:08:00.564 A little piece of tape to make a sealed cavity. 00:08:01.071 --> 00:08:04.090 So now the sample is completely enclosed. 00:08:07.163 --> 00:08:10.104 And we are ready for a spin. 00:08:11.257 --> 00:08:13.321 I'm pushing and pulling with this object. 00:08:13.321 --> 00:08:16.484 I'm going to load this up ... 00:08:16.484 --> 00:08:18.790 and you see the object starts spinning. 00:08:18.790 --> 00:08:20.827 Unlike a regular centrifuge, 00:08:20.827 --> 00:08:24.629 this is a counter-rotating centrifuge. 00:08:24.629 --> 00:08:27.711 It goes back and forth, back and forth, 00:08:27.711 --> 00:08:29.659 and I'm charging it up -- 00:08:29.659 --> 00:08:31.864 and you see it builds momentum. 00:08:32.309 --> 00:08:33.359 And now -- 00:08:33.359 --> 00:08:35.134 I don't know if you can hear this -- 00:08:35.134 --> 00:08:37.053 30 seconds of this 00:08:37.053 --> 00:08:41.524 and I should be able to separate all the blood cells with the plasma. 00:08:42.098 --> 00:08:45.019 And the ratio of those blood cells to plasma -- NOTE Paragraph 00:08:45.019 --> 00:08:47.033 (Applause) NOTE Paragraph 00:08:48.678 --> 00:08:52.437 Already, if you see right here, 00:08:52.437 --> 00:08:54.216 if you focus on this, 00:08:54.216 --> 00:08:57.502 you should be able to see a separated volume 00:08:57.502 --> 00:08:59.383 of blood and plasma. 00:08:59.383 --> 00:09:02.778 And the ratio of that actually tells me whether I might be anemic. NOTE Paragraph 00:09:03.157 --> 00:09:07.115 One the of aspects of this is we build many types of Paperfuges. 00:09:07.350 --> 00:09:11.839 This one allows us to identify malaria parasites 00:09:11.839 --> 00:09:13.679 by running them for a little longer, 00:09:13.679 --> 00:09:17.268 and we can identify malaria parasites that are in the blood 00:09:17.268 --> 00:09:20.614 that we can separate out and detect with something like a centrifuge. 00:09:20.957 --> 00:09:25.460 Another version of this allows me to separate nucleic acids 00:09:25.460 --> 00:09:28.944 to be able to do nucleic acid tests out in the field itself. 00:09:29.605 --> 00:09:34.088 Here is another version that allows me to separate bulk samples, 00:09:34.088 --> 00:09:35.681 and then finally, 00:09:35.681 --> 00:09:37.699 something new that we've been working on 00:09:37.704 --> 00:09:42.263 to be able to implement the entire multiplex test on an object like this. 00:09:42.522 --> 00:09:46.859 So where you do the sample preparation and the chemistry in the same object. NOTE Paragraph 00:09:47.635 --> 00:09:49.040 Now ... 00:09:49.040 --> 00:09:50.193 this is all good, 00:09:50.193 --> 00:09:52.070 but when you start thinking about this, 00:09:52.070 --> 00:09:54.341 you have to share these tools with people, 00:09:54.341 --> 00:09:57.724 and one of the things that we did is we just got back from Madagascar -- 00:09:57.724 --> 00:10:00.224 this is what clinical trials for malaria look like -- NOTE Paragraph 00:10:00.224 --> 00:10:01.223 (Laughter) NOTE Paragraph 00:10:01.223 --> 00:10:03.532 You can do this while having coffee. 00:10:03.701 --> 00:10:05.717 But most importantly, 00:10:05.717 --> 00:10:09.670 this is a village six hours from any road. 00:10:10.346 --> 00:10:14.932 We are in a room with one of the senior members of the community 00:10:14.932 --> 00:10:16.468 and a health care worker. 00:10:16.468 --> 00:10:20.035 And it really is this portion of the work that really excites me the most -- 00:10:20.035 --> 00:10:21.035 that smile. 00:10:21.035 --> 00:10:24.909 To be able to share simple but powerful tools with people around the world. 00:10:25.598 --> 00:10:28.096 Now, I forgot to tell you this -- 00:10:28.096 --> 00:10:30.667 that all of that cost me 20 cents to make. NOTE Paragraph 00:10:31.510 --> 00:10:34.416 OK, in the negative time I have left, 00:10:34.416 --> 00:10:36.649 I'll tell you about the most recent -- NOTE Paragraph 00:10:36.649 --> 00:10:37.650 (Laughter) NOTE Paragraph 00:10:37.650 --> 00:10:39.469 invention from our lab. 00:10:39.671 --> 00:10:41.346 It's called Abuzz. 00:10:41.730 --> 00:10:45.776 The idea that all of you could help us fight mosquitoes. 00:10:45.776 --> 00:10:48.260 You could all help us track our enemies. 00:10:48.260 --> 00:10:52.182 These are enemies because they cause malaria, Zika, chikagunya, dengue, 00:10:52.182 --> 00:10:56.722 but the challenge is that we actually don't know where our enemies are. 00:10:56.989 --> 00:11:00.021 The world map for where mosquitoes are is misssing. 00:11:00.391 --> 00:11:02.070 So we started thinking about this. 00:11:02.070 --> 00:11:04.243 There are 3500 species of mosquitoes, 00:11:04.243 --> 00:11:05.669 and they're all very similar. 00:11:05.669 --> 00:11:07.108 Some of them are so identical 00:11:07.108 --> 00:11:10.752 that even an entomologist cannot identify them under a microscope. 00:11:11.239 --> 00:11:13.047 But they have an Achilles' heel. 00:11:13.047 --> 00:11:15.916 This is what a mosquito flirting with each other looks like. 00:11:16.296 --> 00:11:18.266 That's a male chasing a female. 00:11:18.548 --> 00:11:23.380 They're actually talking to each other with their wingbeat frequencies ... 00:11:23.380 --> 00:11:25.922 and thus, they have a signature. 00:11:26.732 --> 00:11:30.347 We realized that using a regular phone, 00:11:30.347 --> 00:11:32.911 a five to 10 dollar flip phone -- 00:11:32.911 --> 00:11:35.036 how many remember what this object is? NOTE Paragraph 00:11:35.036 --> 00:11:36.038 (Laughter) NOTE Paragraph 00:11:36.038 --> 00:11:40.222 We can record these acoustic signatures from mosquitoes. NOTE Paragraph 00:11:40.222 --> 00:11:42.090 I'll tell you exactly how to do this -- 00:11:42.090 --> 00:11:43.818 I caught some mosquitoes outside. 00:11:43.818 --> 00:11:46.665 Unlike Bill, I'm not going to release them. 00:11:46.957 --> 00:11:49.963 But I will tell you how to record from this. 00:11:49.963 --> 00:11:52.507 All you do is you tap them and they fly. 00:11:52.507 --> 00:11:53.755 You can first test -- 00:11:53.755 --> 00:11:55.530 I can actually hear that. 00:11:55.530 --> 00:11:57.900 And you bring your phone which has microphones -- 00:11:57.900 --> 00:12:00.366 it turns out the mics are so damn good already, 00:12:00.366 --> 00:12:01.788 even on regular phones, 00:12:01.788 --> 00:12:04.113 that you can pick up this [near-field] signature. 00:12:04.113 --> 00:12:06.274 And since I'm out of time, 00:12:06.274 --> 00:12:09.965 let me just play the recording that I made a day ago. NOTE Paragraph 00:12:10.557 --> 00:12:12.754 (Mosquitoes buzz) NOTE Paragraph 00:12:12.754 --> 00:12:15.499 This is all the charming sound that you heard before 00:12:15.499 --> 00:12:16.863 that you all love. 00:12:18.937 --> 00:12:20.381 One of the contexts of this 00:12:20.381 --> 00:12:23.791 is being able to do this with a regular cell phone 00:12:23.791 --> 00:12:26.951 allows us to map mosquito species. 00:12:27.658 --> 00:12:29.373 Using a flip phone, 00:12:29.373 --> 00:12:32.638 we mapped one of the largest acoustic databases 00:12:32.638 --> 00:12:37.502 with 25 to 20 species of mosquitoes that carry human pathogens. 00:12:37.782 --> 00:12:39.615 And from this and machine learning, 00:12:39.615 --> 00:12:41.276 anybody who uploads this data, 00:12:41.276 --> 00:12:43.330 we can identify and tell the probability 00:12:43.330 --> 00:12:46.134 of what species of mosquitoes you're actually working with. 00:12:46.134 --> 00:12:47.203 We call this Abuzz, 00:12:47.203 --> 00:12:48.845 and if any of you want to sign up, 00:12:48.845 --> 00:12:50.169 just go to the website. NOTE Paragraph 00:12:50.675 --> 00:12:54.817 Let me close with something that's very important and dear to my heart. 00:12:55.600 --> 00:12:59.570 One of the challenges of today is we have terrible problems. 00:12:59.570 --> 00:13:02.552 We have a billion people with absolutely no health care, 00:13:02.552 --> 00:13:03.550 climate change, 00:13:03.550 --> 00:13:04.760 biodiversity loss, 00:13:04.760 --> 00:13:06.329 on and on and on. 00:13:06.329 --> 00:13:09.279 And we hope that science is going to provide the answer. 00:13:09.646 --> 00:13:11.935 But before you leave this theatre today, 00:13:11.935 --> 00:13:14.066 I want you to promise one thing. 00:13:14.066 --> 00:13:16.658 We're going to make science accessible. 00:13:17.250 --> 00:13:19.412 Not just to the people who can afford it, 00:13:19.412 --> 00:13:21.446 but a billion others who can't. 00:13:21.904 --> 00:13:26.365 Let's make science and scientific literacy a human right. 00:13:27.620 --> 00:13:32.491 The moment that you pass the tingling feeling of making a discovery 00:13:32.491 --> 00:13:34.670 to another child, 00:13:34.670 --> 00:13:38.360 you're enabling them to be the next group of people 00:13:38.360 --> 00:13:40.610 who will actually solve these problems. NOTE Paragraph 00:13:40.610 --> 00:13:41.698 Thank you. NOTE Paragraph 00:13:41.698 --> 00:13:43.060 (Applause)