Utility Fog

[hunvreus]

https://en.wikipedia.org/wiki/Utility_fog

[mgsouth]

Quote of the day: "The foglets' bodies would be made of aluminum oxide rather than combustible diamond to avoid creating a fuel air explosive."

[brad0]

This is cool! It reminds me of that material the protagonist creates in Big Hero 6.

At such a small size though, would it be possible to breathe it in?

[vimax → brad0]

You could breathe one, but I imagine you would not usually encounter a single one by itself. They would always be in the form of a connected cloud with arms stretched out attached to another. If you walk through the cloud, they'd detach making a hole and pull back away from you.