I don't think 'i robots' are hard scifi. Today i sixth times read The greatest 'True names'(1981) by Vernor Vinge, it is an incredible AI cyberpunk hard scifi novel,aslo a great literature.
Update: Thanks for all the great recommends,it is greatest time to find ideas in these books today. Please aslo add the book publish year,i think it will be helpful to see the writer's wonderful superior consciousness.