Flexible, Stretchable, Implantable LED Arrays Created 147
Zothecula writes "Researchers from the University of Illinois at Urbana-Champaign have created bio-compatible LED arrays that can bend, stretch, and even be implanted under the skin. While this might cause some people to immediately think, 'glowing tattoos,' the arrays are actually intended for activating drugs, monitoring medical conditions, or performing other biomedical tasks within the body. Down the road, however, they could also be incorporated into consumer goods, robotics, or military/industrial applications."
perfect for a real wrist-watch.. (Score:5, Interesting)
Actually (Score:5, Interesting)
While this might cause some people to immediately think, 'glowing tattoos,'
Actually I imagined hooking up a super powerful LED to some nerve endings on the tips of my finger, then using it as a flashlight at any moment by training my brain to trigger the on-off switch like a muscle reaction.
Other immediate reactions included:
Finger Mounted Laser pointers
Hand turning red when commiting crimes, to deliver the line "You caught me red handed".
And holding my breath till my face turns blue.
Or (Score:4, Interesting)
to immediately think, 'glowing tattoos,'
My thought was "animated tattoos tied to pulse and temperature monitors so the tattoo could display imagery to indicate my current mood."
Happy kitten means come and sit a spell. Mushroom cloud means someone needs killin'.
Neat (Score:2, Interesting)
I have a needle phobia and have to get regular tests for RBC/WBC/platelets and hormone levels.
I'd love a solution to my levels that doesn't require a stick into my crappy veins and three to four vials of blood.
Re:Actually (Score:5, Interesting)
1 kcal (food calorie) is 4187 joules, or watt-seconds.
So 1 watt continuos power is about .00024 kcal/second.
A typical LED will light at 1.7 v and 15 mA, or about 25 mW.
Meaning you need about 6e-6 kcal/second to keep it lit.
Glucose is about 4 kcal per gram, so it would consume about 1.5e-6 grams of glucose per second, roughly 90 ug/minute, or 3.5 mg/hr.
For comparison, an average person walking at average speed burns about 100 kcal/hr, which is about 120 watts, but conversion to external work is only about 25% efficient so you can expect to light a 30-watt incandescent bulb walking on a treadmill, or roughly a thousand LEDs. Note, the conversion from LED to LED display isn't direct, as display LEDs are very small and put out less power than discretes; looking up AMOLED shows you can get away with maybe 100 mw total for something with tens of thousands of pixels, and one person on a treadmill could keep a few hundred of those lit.
But if you don't want a treadmill, you still need to find a way to convert the glucose to electricity. Right now the only way to get from here to there is burning the glucose (i.e., self-propagating exothermic oxidation) to make steam energy to drive a dynamo. Even the processes in neural and muscular action aren't a direct conversion; they're electromechanical systems that first use the splitting of bonds in glucose to activate ion-pumping channels that push charged particles to opposite sides of a membrane; then when the channels are triggered they open wide to allow the charges to flood back across, creating an electromagnetic wave along a neuronal wire (axon) or catalyzing further mechanical action in the large molecular levers and ratchets (actin/myosin) that shorten muscle fibers (myofibrils).
So we're back to needing a mechanical source of electricity and batteries. Maybe implant piezo or electromechanical generators in the larger joints, and do a few jumping jacks every few minutes to recharge.
Re:Tramp Stamp (Score:3, Interesting)
Now serving number ____.
I saw a girl with a tattoo that said this on her lower back (tramp stamp area). I think is was a henna tattoo. It was dark, but did not look like a regular tattoo. It still made me laugh though.
Bio-compatible carcinogen? (Score:2, Interesting)
These LEDs are made of gallium arsenide, which is listed as a carcinogen.
I don't think "bio-compatible" means what they think it means.
Re:Actually (Score:4, Interesting)
No, actually, I'm a biomedical engineer who does software because at the time I got my degree it paid about 4X as much and had about 400X as many interesting things going on. Now it's about parity on both fronts.
When I said "implant piezo or electromechanical generators in the larger joints" I was using "the movement the chemical reactions in your muscles cause".
Though it occurs to me now that what we need is a battery muscle. A dish-grown copy of a bicep, say, that is implanted somewhere under the skin (horizontally across the forward processes of the pelvis, say, where most people store belly fat as a bulge anyway) attached to a linear electromechanical generator and coopting a nerve from a small, little-used, almost unnecessary, possibly evolutionary-holdover muscle such as the cremaster. It wouldn't be hard to learn how to move that muscle with that nerve. Then, whenever your eye-implanted display shows "LO BATT", you'd think "waggle my nuts" over and over again, and soon it would show the "FULL BATT" icon.