Embedded Technologies: Power From the People
Energy harvested from our bodies will make possible mind-boggling gadgetry
- By Michael Belfiore
- Smithsonian magazine, July-August 2010, Subscribe
Sensor-studded clothing worn by a soldier tracks his movements and vital signs. A disposable electrocardiogram machine the size of a Band-Aid monitors a heart patient. A cellphone is implanted in a tooth. Scientists and engineers are trying to develop such “embedded” devices: miniature electronics that plug people into computer and communication networks.
Consider contact lenses that function as computer screens. A University of Washington research team, led by electrical engineering professor Babak Parviz, has developed a prototype lens fitted with a tiny radio (for receiving data) and a light-emitting diode, or LED (for displaying data to its wearer). The technology has prompted comparisons to the computer readouts that flash in the eyes of the cyborg in the Terminator films.
In theory, the device converts electronic signals into ever-changing displays projected onto the contact lens and visible to the wearer, perhaps like a movie subtitle. If wirelessly connected to, say, a smartphone with voice-recognition software, a hearing-impaired person wearing such lenses might see a speaker’s words translated into captions.
But engineers developing such embedded technologies face a big obstacle: power. The devices pack so much gadgetry into such tiny spaces that even the smallest batteries would be too bulky, never mind the inconvenience (and potential discomfort) of replacing them.
To solve the power shortage, the Defense Advanced Research Projects Agency (DARPA)—the U.S. Department of Defense agency behind technologies that led to the Internet and the Global Positioning System, among other things—launched an Energy Starved Electronics program in 2005 with MIT. Researchers there have a new idea for powering embedded electronics: “scavenging” energy from the human body.
Obviously, our bodies generate heat—thermal energy. They also produce vibrations when we move—kinetic energy. Both forms of energy can be converted into electricity. Anantha Chandrakasan, an MIT electrical engineering professor, who is working on the problem with a former student named Yogesh Ramadass, says the challenge is to harvest adequate amounts of power from the body and then efficiently direct it to the device that needs it.
In the case of harnessing vibrations, Chandrakasan and his colleagues use piezoelectric materials, which produce an electric current when subjected to mechanical pressure. For energy scavenging, ordinary vibrations caused by walking or even just nodding your head might stimulate a piezo material to generate electricity, which is then converted into the direct current (DC) used by electronics, stored in solid-state capacitors and discharged when needed. This entire apparatus fits on a chip no larger than a few square millimeters. Small embedded devices could be directly built onto the chip, or the chip could transmit energy wirelessly to nearby devices. The chip could also use thermoelectric materials, which produce an electric current when exposed to two different temperatures—such as body heat and the (usually) cooler air around us.
Powered by our own bodies, embedded technology promises not only to provide data wherever and whenever we need it but to transmit real-time data about ourselves. A jacket fitted with heating pads or the thermostats in our homes could adjust based upon our body temperature.
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Comments (10)
I totally agree although this tec is 13 years old. I have one working in my body against my will.
Posted by frank harper on January 31,2012 | 07:57 PM
The thought of implementing this idea of harnessing the electical potential of our own bodies and using it as a military benefit/advantage is very interesting, but the first soldier captured or killed equipped with this technology during an engagement with enemy forces will essentially turn the technology over the the enemy to be back engineered, so to plan on it being exclusive to our military is not logical.
Posted by Bill on December 21,2011 | 06:59 PM
Furthering: Put micro wind turbines at tips of nose-hairs (tethers to the working kites) and generate electricity for use for devices embedded. AirborneWindEnergy (AWE).
Posted by Joe Faust on July 23,2010 | 11:13 PM
just like hydroelectric motors,a device connected to artery should do the trick
Posted by john zub on July 17,2010 | 11:23 PM
What about the MOST obvious -- hearing aids? Battery replacement is NOT green, tedious, and costly. Now especially with smart power maangement, lower power DSPs, etc. the power needs could be reduced.
Or glucose monitoring. type 2 diabetes is nearly epidemic.
Posted by Fred Stein on July 17,2010 | 06:19 PM
My first thought was after reading the title: great! why not use energy for my laptop from energy that my body supplied?!
This way we would cut back on other anti-nature energy resources. Why just not stick something on my skin and harvest the energy that is somehow coming out...
very interesting
Posted by Ati on July 17,2010 | 01:53 PM
Why not harness chemical energy? Can't we make a system that plugs into our blood stream and harness the energy?
Posted by Diego Alcorta on July 16,2010 | 02:32 PM
It seems like all of the kinetic energy one could hope for in powering the prototype contact lenses could be found in the blink of an eye. Literally. A hard, gas permeable lens is brushed by the eyelid about a thousand times each hour. That should be enough friction to power a system as tiny as the one described. Or, what about a solar cell. Sure, they aren't very efficient yet, but the whole point of opening one's eyes is to let in light. Develop a contact lens that can transfer kinetic and solar energy into usable electricity and DARPA will beat a path to your door.
Posted by joshua haveman on July 16,2010 | 12:17 PM
Soldiers are so overloaded (and wrapped in body armor) that to move they must exert themselves greatly. There is more heat to "harvest" than from a sedentary person.
Posted by Old MSgt on July 16,2010 | 11:09 AM
I would definitely like to find out more information about the research being done on thermal extraction. I have my suspicions about the viability of current techniques being able to supply *enough* power. Certainly there are materials which change voltage when in contact. I am not knowledgeable on how high of a potential can be obtained. Interesting read on the contact lenses, I've been following Babak's research in this area for a while now. Great insight on the power harvesting techniques as well.
Posted by Peter VanNess on July 2,2010 | 03:08 PM