Comment by TeMPOraL

> From the biggest land animal to the smallest microbe it’s all chemistry.

Batteries are chemistry. ATP is a chemical battery.

The difference between living things and our machines is primarily in manufacturing methods: we do things in bulk, because we reach from the top with crude, meter-scale tools; nature glues things up from lots of tiny biomolecular nanomachines, and each of those tiny machines has to carry its own power source!

Still, it's highly likely that any form of "smart dust" will resemble living cells as much as, or even more so, it will resemble miniature devices we build today, simply because that's the kind of chemistry that's efficient at smaller scales.