Nanotechnology is not simply about making things smaller | Noushin Nasiri | TEDxMacquarieUniversity

I grew up in a small city in the north of Iran next to the Caspian Sea my father is an agricultural engineer a country boy who values academic achievements it's my favorite person in the family who is full of passion for life and always has a question to ask always no matter how old you are how educated you are how interested you are he always has a question to challenge you a question that is simple but somehow difficult to answer when I was eight he asked me why is the time difference between countries I answered

very proudly of course because the earth is spinning Papa it means that it takes seven hours for Canada to be in the same geographical location as we are right now is it true then why do people bother to buy a ticket and spend eighteen hours to travel to Canada for the time difference is only seven hours why not hire a helicopter go up stand still while the earth is spinning and get down to Canada only after seven hours yes my father who planted the curiosity seeds in me he taught me to not simply accept anything

as a fact in this world but look for a reason a scientific reason behind every single fact why is the sky blue why does it end red at sunset why are clouds white why are rain droplets is spherical in shape not cubic so as I'm truly his daughter I'm going to do the same today I'm gonna ask you a question a very simple one of course what will happen if I drop this pen gravity right simple now what will happen if I drop a nano particle does gravity have the same effect in order to answer

this question we need to know what a nano particle is nano means one billionth a nanometer is one billionth of a meter to help us imagine nano size this is a baseball bat which is about one meter long now if you take its length and divide it by 100 you get to the size of my fingertip which is about one centimeter take that and divide it by ten and you get to the size of an either eye which is only one millimeter take that and divide it by 10 again and you get to the diameter

of a human hair which is there a hundred micrometer this might be the smallest division you will be able to see it by naked eye take that and divide it by 10 again and you get to the size of a blood cell which is about 10 micrometer take one blood cell and divided by 10 again you get to the diameter of a bacteria which is only 1 micrometer take one bacteria and divide by 10 again you get to the size of a virus which is around 100 nanometer now if you are in the scale of

nanometer pretty close huh but not there yet all you have to do is to take one virus and this time divided by 100 and you get to the size of half of a DNA which is only one nanometer one nanometer it means only five atoms sitting end to end one nanometer one billionth of a meter what what is it all about but if you're so obsessed about making things smaller and smaller in size I understand smaller is lighter it's cheaper is faster and is a smarter this is what we consider to be the first computer

made in 1940s big complicated and not very smart today every one of you have your own smartphone smaller device which is millions of times more powerful than the first computer but nanotechnology is not simply about making things smaller for the sake of it it's because science has different rules in the nano scale in fact if you make materials and you if you take materials and stop making them smaller and smaller in size down to nanometers the materials physical and chemical properties change dramatically the best example is the gold ring on your finger which is golden

yellow in color but a gold nanoparticle is not necessarily golden it can be red purple blue or even green this is called quantum effect materials reduce to nano size can suddenly show very different properties than what they show on the Matra scale now let's get back to that pen and the nano particle in our everyday world gravity is the most important for spin counter it dominates everything around us gravity is necessary for rain droplets to fall or for water to drain even for our hair to hang down around our head but on the nano scale

gravity is nothing it's negligible it is much less important that other forces like electromagnetic forces between atoms and molecules or the thermal vibration of atoms in a nano structure and if I drop this nano particle the dynamics of such a small object would be much more sensitive to the factors like Brownian motion or turbulent diffusion than gravity in short the game of science has different rules when you play it in the nano scale but if we know these rules if we learn how to play this game we can design new materials we can man you

plate the properties we can train them and make them behave the way we want them to do in my laboratory we are doing this by designing not only small but intelligent nano sensors that can be trained to sniff up your breath yes your breath you might say no visible but your breath tells a story and viola the story can be used in RBT and get you in trouble we can use it to save your life you know we smell different when we are sick although our nose is not strong enough to detect it but in

the same if the body chemistry changes when we are sick and as a result of that chemistry change some ball markers are released into our breath and give us this unique opportunity of detecting disease just by sniffing out the breath but there's one big challenge here these ball markers in human breast exist at a very low concentration down to parts per billion here is an example acetone is a real noun ball marker for diabetes now if one in a million particle in your breath is acetone you're healthy if two in a million particle of your

press or acetone you have diabetes so the ball markers concentration difference between healthy people and patients is one part per million 1 ppm house mods that let me visualize it the entire Harry Potter series seven books has 1 million 84,000 170 words which makes the word Dumbledore on page 17 of Harry Potter and the Philosopher's Stone a little bit less than 1 ppm so in order to detect disease using human breath rather than blood we need to fabricate and design sensor super-sensitive to detect ppm or even less ppb before nanotechnology was impossible to precisely detect

such a tiny concentration but today to make sensors like this one which are hundreds of times more accurate that what we need we can detect two parts in every billion particles in your breath but how does nanotechnology help us to fabricate such a sensitive sophisticated sensor it's all related to the available surface area here we have a cube is the length width and height of 20 centimeter now what happens to the cube surface area if I divide it into eight cubes you see I'm not changing the material neither its mass nor volume I'm just creating

more surfaces so the available surface area is doubled now imagine if I divide each of these cubes into smaller and smaller cubes until having cubes with 20 nanometer length if I do that we're gonna have ten million times larger surface area same material same mass same volume but ten million times larger surface area in fact by shrinking the structural elements of my sensor down to nanoscale I can significantly increase the available surface area to capture that tiny concentration of ball Markel in your breath nanoscience is not just one science is a platform that includes biology

chemistry physics electronics medicine material science and engineering it's shown is potential to positively impact our quality of life and breath analysis as one of many research areas in this field can empower us with a better diagnostic technology and can help us to save many many lives in the near future thank you [Applause]