It's all just matter and energy.
Indeed - very few (sane) people dispute the fact that consciousness can be generated with non-biological hardware (using silicon). We know that consciousness is the result of matter and energy - a more interesting question IMO, is: matter down to what level ? does the brain only use "classical" physics principles to generate consciousness, or does it somehow exploit quantum principles (we certainly know that natural selection has made use of those in some cases - see photosynthesis).
Maybe the brain requires quantum mechanics for randomness (where does a new, original idea come from ? it may simply be extremely complex recombination of previously seen concepts and ideal; but then again, it may include a true source of randomness), in which case the only thing required to create consciousness on a silicon medium would be a "true" source of randomness. Such a source of randomness in the brain could also come, for example, from the interaction between cosmic rays and particles in the brain - an interaction we actively correct for in RAM using error checks.
Then again, maybe the brain requires quantum mechanics for something far more fundamental needed for consciousness - in which case the only efficient way to create an artificial consciousness may be to use a quantum computer, and using a "classical" computer may not be possible.
In any case, given the current rate of progress, I'd be very wary of making any assumption about the progress of tech and research, in that domain or any other - time will tell