 What is nanotechnology, and why should you care? Before we get too technical, try this. Pick up something that's close to you. Anything, it might be a glass, or a smartphone, or even a t-shirt. It doesn't really matter what. Now, think about what this thing does well. It could be holding water or chasing Pokemon, or if you're thinking about that t-shirt making you feel awesome. Then think about what it doesn't do so well, perhaps smashing when you drop it, or running out of power just when you need it, or thinking about that t-shirt still, smelling of BO after you've worn it for a couple of days. It might not be obvious, but all of these things, the good stuff and the bad, depend on the individual atoms that make up the things around us, and importantly, how they're put together. It's a bit like a car working because of how all the individual bits are arranged. It's not just a case of having four wheels, an engine, and a steering wheel. They all have to be in the right place if you want a car that gets you to where you're going without falling apart. Of course, atoms are a bit smaller than the wheels on a car, but the same idea holds. How the different atoms in something are arranged can affect things like how strong or how weak it is, or if it conducts electricity, or if you can see through it, or even what it feels like. In fact, pretty much anything that the stuff around you does, it does because of how all the different atoms it's made of are put together. And this includes the things that you don't want stuff to do, like breaking or smelling, or running out of power. If we were really smart, of course, we'd make the stuff around us work better simply by doing a better job of arranging the different atoms it's made of. And if we were smarter still, we could make totally new stuff by putting atoms together in ways that we'd never done before. We could even start to create stuff that behaves in quite unusual ways, because when you start playing around with atoms, you can tap into some really weird quantum physics. The trouble is, atoms are really small, more than a million times smaller than the tip of your pinky finger, and that means they're not that easy to work with. But over the past few years, scientists and engineers have become increasingly good at designing and engineering materials down the level of atoms or small groups of atoms. And because this new technology involves doing stuff at such a minute scale, it's called nanotechnology. Using their new skills, nanotechnologists are beginning to do cool stuff like creating materials that are really good at turning sunlight into energy, or using nanoscopically small particles to deliver anti-cancer drugs, or even turning polluted water into drinkable water. They're even finding new ways to make glass that doesn't break when you drop it, batteries that last longer, and even t-shirts that smell fresh after you've worn them for a few days. This is really powerful tech. It's helping us to do stuff we couldn't even dream of just a few years ago. But because nanotechnology is so powerful, we need to be really careful how we use it, just in case we end up causing more problems than we solve. The last thing we want is to make better solar cells that also destroy the environment, or design more efficient water filters that just happen to cause more pollution. Because of this, scientists and others are working hard to make sure we develop and use nanotechnology responsibly. But this isn't just down to nanotechnologists. It's something everyone can be part of, because at the end of the day, it's up to us to decide just how much we want nanotechnology-enabled products and what we're willing to put up with to get them.