Realistically nanomachines is just a nice word for âso we manufactured these germs than help you out, see?â (as the functional difference between machine and lifeform is reduced to zero the smaller you get) so the chances of them actually working and self-repairing at T-1000 Terminator speeds is pretty low (if it was feasibly possible we should probably see animals that could already do that in nature.)
Hell, the blob probably counts as a nanomachine swarm (Lovecraftâs Shoggoths are probably one of the earliest depictions I can think of for scientific namomachines) and the blob might could get around the whole âneed energy for mass growth equationsâ too using its trans-dimensional connections.
Now, someone loony in the laboratory âcouldâ have been working on some âblob armorâ but it shouldnât take a genius to realize why actually wearing a suit made of from mutating alien invading goo from another dimension to help fight the mutating alien goo from another dimension is a poor battle plan.