chitin

kitiini puhekieltä A complex polysaccharide, a polymer of N-acetylglucosamine, found in the exoskeletons of arthropods and in the cell walls of fungi; thought to be responsible for some forms of asthma in humans.
1880, Arthur Gamgee, http://books.google.com/books?id=Sr9uxO_JJx4C ''A Text-book of the Physiological Chemistry of the Animal Body, Macmillan, p. 299

Chitin usually occurs throughout Invertebrates in the form of an investment to the outermost cellular layer or ectoderm.

The robot’s energy source is the sugar in the polysaccharide called chitin that makes up a fly’s exoskeleton.