Boffins working on biodegradable flexi LED implants • The Register
http://www.theregister.co.uk/2009/11/03/silk_electronic_implants
"Boffins in America are working on biodegradable, flexible electronic devices printed on silk, which could be implanted in the human body and would decay naturally over time. Applications could include LED displays inlaid beneath the skin, or direct nerve-controlled interfaces."