The artist who developed the mobile: American sculptor Alexander Calder

Met Museum DEC2011 Calder Mobile
Originally uploaded by Mark B. Schlemmer

Alexander Calder (1898 – 1976) was an American sculptor and artist most famous for inventing mobile sculptures.

In addition to mobile and stable sculpture, says Wikipedia, Alexander Calder also created paintings, lithographs, toys, tapestry, jewelry and household objects.