There is matter and only matter. Humans are a configurations of matter and those specific configurations have the property we hold so dear and call 'consciousness'. There is no reason whatsoever to suppose you couldn't synthetically arrive at a configuration of matter that displays the same emergent behavior. This is the basic thesis of the famous book 'Godel, Escher, Bach' by Hofstadter. I am a strange loop. Any similar strange loop will display the same properties.
Any question to this regard probably makes you a closet Cartesian dualist. When you drill down, most people turn out to be that. (Some intermediate philosophical positions are possible, but they are subtle and rarely held consistently by someone that hasn't spent a course studying the matter in detail).
What I'm guessing in my previous post is that it may turn out that you can most easily achieve a configuration that displays consciousness by using biological materials. In that case, any future conscious machine would probably have a core of material similar to our brain. Which more poignantly raises the ethical questions related to creating such machines.
(BTW, note we are conflating 'any consciousness' and 'intelligent consciousness' by focusing on humans)
Is it possible that machines develop consciousness like ours? THAT is the question that needs to be answered and which is far more interesting than "from a technological point of view only"