From Schopenhauer 'Metaphysics of Love' to Bjork/Cunningham 'All Is Full of Love'
Machines will never have real emotions because they don't need them.
Love doesn't make any sense in a machine because we only have this feeling to feed the passion and attraction necessary to provoke reproduction of our species (Schopenhauer).
So machines doesn't need to play sex to reproduce they will generate themselves in assemblage lines.
In this way what we need from robots is not a development of structures to generate emotions in robots we don't need them to be feeling robots.
They will need to be able to generate representations of human emotions - expressing emotions - and also able to recognize human emotions and having algorithms able to response to humans.
Robots will need this only in communication between robot-human not robot-robot.