Harvesting Energy from the Human Body
Late-Eight writes "Scientists at the Georgia Institute of Technology are working on a new type of nanogenerator that could draw necessary energy from flowing blood in the human body. The hope is to incorporate the new nanogenerator into biosensors, environmental monitoring devices and even personal electronics that will require no fuel source, internal or external. Once completed, this new cellular engine could find various applications, even beyond medicine."
Ugh, fine. . make me RTF :-p Yes I'd call it negligible, they say that their current design can do a few nanoamps at below 0.5v but hope to get a design that can pump out a microamp at 0.5v. Lets assume they perfected their "high-power" design and look at what it does. 0.000000001A is 1 microAmp, multiply that by 0.5v and you get 0.0000000005W or 0.5 microWatts. Having this thing run for 24 hours would give us 12 microwatt-hours which according to google is 0.0103250478 calories. So if it were 1% efficient (I'd be sure its quite a bit higher) it would draw about 1 calorie a day. . .or about 1/4 of a gram of sugar.
If you are about to mod me down, keep in mind that this post was most likely sarcastic.
According to TFA, this should not be impairing blood flow, regardless of where it is installed. It is not some sort of hydroelectric... er, vitroelectric dam, rather, if I understand correctly, it is powered by harnessing the vibrations of the pulse itself, that are otherwise just absorbed by the vein walls.