Battery-Free Mobile Devices Communicate Pulling Signals From Air
Researchers at the University of Washington have developed wireless devices that are powered and communicate solely by harvesting energy from existing television and cellular transmissions. The technology is called “ambient backscatter,” and it transforms existing wireless signals into both power source and way to communicate. (Source: University of Washington)
"Researchers at the University of Washington (UW) have developed wireless devices that are powered and communicate solely by harvesting signals from existing television and cellular transmissions in the air."
Elizabath, that's great and I think self powered board is a good model. I would like to whether anywhere (cell/battery) the energy is stored in wireless device or it's like a real time sourcing from air.
I agree. This technology could really help with in-the-field devices that are placed in places where batteries are hard to change. This also sounds like the ambient power sources is easier to harvest than ambient vibrations. Not all device placements are near freeways and bridges.
He said he thinks the technology could open up more applications than you could ever dream of. I second that notion. This is very futuristic. Considering how much stray RF there is floating in the air, right in front of your eyes, at this very instant; I always thought it was a fascinating fact that turning on a transistor radio right in your hand could catch the signal of anything transmitting within 50 miles. Think of how much energy that actually is, available for this harvesting concept!
A wildlife biologist contacted me to ask how he could extend the battery life of animals he was tracking. I told him there are tracking collars that can sleep 90 percent of the time using a micro-amp of current while storing sunlight energy during the day. These devices might only need to wake up to get some data for a second and transmit it to a Zigbee or wi-fi device or a satellite -- then go back to sleep.
Design News and Digi-Key sponsored a class by Paul Nickelsberg April 15 - 19, 2013 on energy harvesting. I was amazed that in lectures four and five, he introduced devices that could harvest energy that produced only millivolts of output (vibrations, for example, and signals from the "air"). What's cool is that these signals from microwave radiation would have been just wasted. In fact, they might have contributed to reflected confusion in other networks, so harvesting these might do others a favor. Well, not really. There is so much radiation out there.
I encourage others interested in this subject of harvesting micro amounts of energy to take the archived class.
It definitely seems like a good solution for these types of situations, Rob. I remember that I did a story about a similar device that harvests energy from ambient electricity sources developed by a German student, and there was a lot of debate about "stealing" the electricity. I didn't really agree with this theory, but I'm wondering if anyone thinks so in this case, too. http://www.designnews.com/author.asp?section_id=1386&doc_id=260486
Thanks for this perspective and that information, 78RPM. There really is a lot of potential in energy harvesting, especially for these micro devices. In fact, it's really probably the best application of the technology, given that a lot of them don't need a lot of power and could really be self-sustaining.
There was a project in an issue of Popular Electronics in 1958 called "Stolen Power Radio" and I built one and it worked well. It was 2 AM radios on a single board. the first was a standard 2 transistor AM radio and the second was just the tuner section and a diode rectifier. You would temperarily connect a headphone th the second radio and tune it to the strongest AM station in town and then the rectified signal would power the second radio.
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