The piece is constructed of steel, concrete, brass, urethane rubber, and foam. Several mechanisms are chained together to produce the awkward spinning of the figure suspended in the center of the hoop. The overall effect works well with the title of the automaton: A Series of Passionate but Arbitrary Decisions.
Apart from being a great piece with an outstanding title, it also serves to show how useful good old-fashioned pin-wheels can be. Here the artist is using them to change the axis of rotation -- a fairly common use for pin-wheels. The particularly novel application is in the double-ratchet mechanism in which the pin-wheel's pins serve as "teeth" that are pulled in order to advance the motion. Clever, economical, and -- I'll wager -- robust.