These three verbs really are confusing. Awaken seems the safest way to go.
The meanings are pretty much the same, but
wake and
awaken sound very natural when used as transitive (or intransitive) verbs.
He wakes/awakens his children at 7 each morning. (I actually use the phrasal verb
wake up more often than
wake.)
But
awake seems more at home as an intransitive verb.
I awake at 7 each morning. sounds natural,
but
I awake the children at 7. seems stilted.
Another slight difference is that
awaken is used more often metphorically.
The experience awakened his interest in art history. Woken has a wonderful Old English sound to it, and perhaps for that reason
it seems to be used less often than
awakened.