Theoretically it's possible to create atoms from raw particles and to assemble them; science fiction posits "replicators" in Star Trek, http://en.wikipedia.org/wiki/Replicator_%28Star_Trek%29, and elsewhere.
It is done, a few billion or trillion atoms at a time, when matter is bombarded by protons in a cyclotron or linac. Americium, 241Am, for example, was first produced that way, and you probably have some in smoke detectors in your house, though now it is extracted from the random products of nuclear fission reactions. See http://en.wikipedia.org/wiki/Americium.