I will address, JUST FROM THE STANDPOINT OF PSYCHOLOGY (i.e. behaviors and environmental aspects), ALONE, not only how robots can/will become conscious, but also how FULL artificial intelligence (complete simulation of all major human behaviors) will be possible :
All qualitative changes in behavior (particularly, especially including cognition and cognitive processes) have as their key CAUSE(S), at their inception, SOME OVERT RESPONSE(S) _TO_ particular aspects of the PRESENT environment. (The overt responses, in the case of an organism well-along in its ontogeny, may well be as subtle as perceptual/attentional shifts (