Physical scale, tiny robots, and life

Sabine Hossenfelder has an interest post (and video) about small, smaller, and vanishingly small robots, These tiny robots could work inside your body:

Here's a passage:

No, the problem with tiny robots is a different one. It’s that, regardless of whether the prefix is nano, micro, or xeno, at such small scales, different laws of physics become relevant. You can’t just take a human sized robot and scale it down, that makes no sense.

For tiny robots, forces like friction and surface tension become ...