Are the robots we create alive?
Two of my favourite SciFi authors I've read have touched on the topic of sentient AIs, Neil Asher and Iain M. Banks. In both of the universes they create, humans have essentially been overtaken by benevolent AIs, who do all of the organisational work and governing, while the humans are given the resources they need to take up pretty much any lifestyle they want because mechanisation has made any form of labour unnecessary.
Their approaches differ, though, in how they view sentience. In Banks's work, any computer system above a certain level of power is legally required to be made sentient. From this, I interpret that sentience is not an intrinsic property of a powerful computer, but rather a certain organisation and programming of said computer. Asher, on the other hand, has multiple stories about a certain humanoid robot (the Brass Man, 'Crane', in case you want to read the books) whose processor-crystal was fractured, but who continued to function with multiple personalities. From this, unless the programming was particularly redundant, I would infer that after a certain amount of processing power, and given the right seed data, sentience sort of springs into place. Both feature brain-network interfaces, called 'neural nets' by Banks and 'gridlinking' by Asher, but only Asher covers cyborgs and human augmentation with processing nodes and robotic limbs. Asher also features 'golems', which are weak (although smarter than human) AIs in a humanoid chassis covered in syntheskin, which run a human emulation program and thus experience love, fear etc, and are generally indistinguishable from humans, although the emulation can be turned off during emergencies and the syntheskin isn't necessary for operation. Both authors also follow different post-Einstienien physics, which I find particularly interesting =)