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."
grinding.be » Blog Archive » two ways the gadgets of the future will be powered by your blood
http://grinding.be/2009/04/23/two-ways-the-gadgets-of-the-future-will-be-powered-by-your-blood
"The yeast-based fuel cell produces around 40 nanowatts of power, compared to the microwatt a typical wristwatch battery might produce ... zinc oxide piezoelectric nanowires that generate an electric current when subjected to mechanical stress. ... harvesting energy from low-frequency vibrations such as the wind or the flow of currents ... powered by simple movements such as walking, or the beating of a heart."