Welcome to Nature’s Nano I’ve always wondered how butterflies and beetles can make these strong and iridescent colours. So if we take a butterfly wing and put it in a microscope we see thousands and thousands of bright blue tiny scales. Each of these scales is covered in tiny ridges running across the scale. Each of these tiny ridges, if you cut right through them, look like a Christmas tree. This structure is finely tuned to reflect only the blue part of light so the butterfly appears bright blue. If we just replace the air in this nanostructure with a bit of liquid you’ll see that it changes colour from bright blue to bright green. It fills in the gaps around the nanostructure and makes it better at reflecting green light. When the liquid evaporates it returns to reflecting blue. Please, don’t squirt butterflies. Life has spent over 3.8 billion years finding clever ways to use the nano scale. Now we can understand nature’s nano secrets, we can use them for ourselves. Many tropical plants have leaves where water just runs off, this keeps them clean. If we look at the nano scale we can see tiny structures which stop the water from sticking. By copying these structures we can make our own water repellent surfaces. Some that even honey doesn’t stick to. Ants have really cool feet, they can stick upside down to surfaces holding up to 100 times their own weight without falling down. If we look closely we see tiny little pads on their feet which help them to stick. By investigating the microstructure of insects feet we can design surfaces hard for them to climb. Bad luck for cockroaches. Pitcher plants eat insects that slip into them but they don’t work unless all of their rim is covered in water. To make sure they’re as slippery as possible they have a nano-trick up their sleeves. We can see how the water spreads, even upwards against the gravity. If we look at them we can see they have lots of grooves running across their rim, and in between these grooves if we look on the nanoscale there are even smaller grooves. This is called a super hydrophilic surface which means that the surface likes the water and pulls it across itself. Once the water is spread thinly across these micro and nano grooves they become very slippery and it’s goodbye ants, hello pitcher plant dinner. Hypdrophilic surfaces have lots of uses, but one particularly excellent one is in a new water filter. This can filter even the tiniest bugs from dirty water making it safe to drink. Even really dirty water. Looking around the natural world is a great way to pick up ideas for things to make ourselves but with nanotechnology we can make new structures that nature has never even tried.