Artificial brains are man-made machines that are just as intelligent, self-aware, and creative as humans. They not only behave in ways that appear sentient, but they are actually in possession of their own sentience, consciousness, and free will.
No such machine has yet been built, but it is only a matter of time. Given current trends in neuroscience, computing, and nanotechnology, it is likely that artificial general intelligence (AGI) will emerge sometime in the 21st century, possibly even in the 2030s.
AGI will probably be achieved through the building of novel, massively-parallel, neuromorphic computing devices that are closely modeled on neural tissue. If we assume Integrated Information Theory to be correct, this implies the AGI hardware must be able to physically alter itself. The human brain, through the self-directed free will of its owner, can develop its own skills and memories by rewiring its own neurons. AGI hardware will inevitably be the same if it is to achieve consciousness.
Of the biggest mysteries in science and metaphysics, i.e. why does the universe exist, what is the ultimate theory of everything, is there intelligent life beyond Earth, etc., human consciousness is one of the most pressing and yet most within our reach.
By reverse engineering the human brain we will come to understand it. By reconstructing and enhancing the brain we will be empowered to push forward our understanding of the universe and to evolve life to the next level.