STM is a powerful tool, used to observe the smallest fundamental building blocks of our world. Structures can be built, words can be spelled out, and even movies can be made by using atoms to draw characters. Using STM, scientists can manipulate individual atoms, controlling where they lie on a surface. The tip may then pick up the atom and drop it back off at another location. If the STM tip is moved very close to an atom, interactions between the two will cause the atom to be attracted to the tip. The unique way STM produces pictures not only enable it to image really small objects, but also allow it to go beyond what a typical camera can do. It should be obvious by now that the way that STM captures an image is pretty different from how a normal camera would. Using sharp wires to take pictures by detecting electrons from surfaces is a technique known as Scanning Tunneling Microscopy, or STM for short. So when the wire produces a “photo”, it is actually visualizing the electrons that the objects hold inside themselves. Atoms, however, are seen by detecting their electrons. With a camera, objects are seen by detecting the photons that bounced off of them.
This is how these atoms are detected, and how their picture is taken. The software connected to the wire will draw a picture based on the electrons it receives, coloring in bright spots where it feels a lot of electrons, and dark areas where it feels it is receiving only a few electrons.
/rutherford-atomic-model-141483941-5c3bb44bc9e77c0001c7a15d.jpg "atom picture")
Objects further away from the wire give only a few electrons, while objects really close to the tip will give it many electrons. This wire can image the shapes of atoms due to a special relation between how far an object is from the wire, and how many electrons it will give up. If the wire is sharp enough at its tip, it will be able to tell which atom the electron comes from.īy moving this sharpened wire tip across a flat surface, electrons may be received from all of the objects present. Electrons travel differently than photons, so instead of a lens, a wire with an extremely sharpened end is used to pull these electrons through to equipment that can detect them. Traditional cameras have a lens that lets the photons through for the camera to detect. Since the particle being used to see with is now different, the “camera“ will need to be different as well. So instead of seeing with photons, like a normal camera, atoms are seen with electrons. Even if two objects are incredibly close, such as two neighboring atoms, it is possible to detect which electron came from which atom. What’s useful is that these electrons don’t suffer the same problem the photons do. If two objects are brought close enough to each other, under the right conditions electrons from one object are transferred to the other. In order to get images of atoms, these photons need to be replaced with another particle better suited to take these tiny pictures. Atoms are simply too small to use photons to take a photograph of. If a photon bounced off of one of them, it would be impossible for a camera to be able to tell which exact atom the photon bounced from.
Two atoms sitting next to each other are too close together to be able to tell apart with photons. Most things “see” by detecting these bouncing photons, which is why both you and your phone have a hard time seeing anything at all when the lights are off.īut what if you want to photograph something much smaller than your dog? What if you want to take a picture of an atom? While microscopes may be used to help see smaller objects, photons have their limits. Your eyes work similarly, taking in all the light particles, known as photons, that are scattering off of objects in the world. Light comes down from the sun, bounces off the dog, and into your camera lens, allowing you to take the photo. Any queries (other than missing content) should be directed to the corresponding author for the article.You’re lining up your phone to take a picture of your dog. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Technical support issues arising from supporting information (other than missing files) should be addressed to the authors. Such materials are peer reviewed and may be re-organized for online delivery, but are not copy-edited or typeset. As a service to our authors and readers, this journal provides supporting information supplied by the authors.
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