Seeing as everything is made of them, you have.

But have you ever seen one on its own?

Over time, microscopes have become more and more powerful, allowing us to see deeper into the world of the ultra-small.

Traditional light microscopes can be used to see things like these onion cells and the structures within them as they divide, pulling apart their chromosomes.

But scientists have come up with a whole host of clever methods to observe far smaller things.

Using beams of electrons instead of light, we can generate detailed images of chromosomes themselves.

Recently, groups of scientists around the world are becoming able to see materials at the most fundamental scale: the atomic.

One group from the University of California in Los Angeles have been getting up close and personal with nanoparticles of platinum, just a few nanometers across.

Each of the tiny dots you can see here are actually individual platinum atoms.

But researchers didn't stop at a two-dimensional picture.

By imaging over 100 slices of the nanoparticle at different angles then removing the noise with a special filter, they were able to map the location of almost every atom.

The information was used to create a three-dimensional reconstruction of the whole particle in unprecedented detail.

It may look blurry, but this particle is estimated to contain over 27,000 atoms and so, like flies in a swarm, they appear to merge together.

Every so often, though, we see the platinum's atomic structure align, granting us a moment of clarity.

This technique is being used to analyse tiny irregularities in the structure of the particle called dislocations.

Dislocations are subtle, like the misalignment of the green and red layers of atoms in this particle.

But nonetheless, they can significantly change the properties of materials, with effects ranging from a change in the efficiency of LEDs to the strength of metal alloys.

Three-dimensional atomic-scale imaging like this is bettering our understanding of the structure of materials on this truly fundamental scale.