Tesla’s dream: Wirelessly powered devices that get their energy out of thin air

For those who know me, it comes as no surprise that one of the men I admire most is Nikola Tesla.

Not the famous inventors like Edison or Newton. Not the renowned geniuses like Einstein or Hawking. And certainly not the great leaders of human history, because nearly all of them became ‘great’ through violence of some sort. Well, except for Mohandas Gandhi.

Nikola Tesla. Genius. Technophile. (I love the guy so much, he’s featured in a work of fiction that I’m writing, albeit in a historical context, not as a living character. And I developed my fondness for the man long before it became fashionable.)

Alas, he was also a man not only ahead of his time, but lacking in the ruthlessness necessary even to see to his own needs. There are many stories about how both Edison and Westinghouse took advantage of Tesla’s lack of business acumen. He died nearly penniless.

Nikola Tesla's portrait

Nikola Tesla (1856-1943), photo at age 34

One of Tesla’s great dreams — which he nearly made a reality — was to develop a system of totally wireless power distribution. His revolutionary idea was to use a quality of electromagnetic fields known as “resonant inductive coupling.” An analogy: Imagine, if you will, a tuning fork vibrating. Put another identical tuning fork next to it, very close, and soon both will be making a sound.

This method is actually in use today, although in much smaller applications and usually over smaller distances: Passive radio-frequency (RF) chips and ID cards. Devices such as phones and toothbrushes that recharge by being put on a platform or inserted into a non-connecting charger. Electrical transformers, such as the ones outside our homes and businesses use the same basic technique — a powerful electric field in one device “inducing” a sympathetic field in another.

Tesla’s dream was to scale this up and do it over vast distances, and he even had some demonstrations where he lit street lamps using what he termed “electrodynamic induction.” In 1899, he managed to illuminate light bulbs at a distance of 100 feet, while experimenting in Colorado Springs, CO.

Cool, huh? Well, researchers at the University of Washington have come up with an even cooler idea. A wireless electronic communication technique that has no dedicated power source at all, neither on the transmitter nor the receiver.

Original Tesla Coil

Tesla’s originally patented coil, which used a system called “the disturbed charge of ground and air method.

The concept is based on using the great soupy sea of electromagnetic signals we already live in. For example, all around us there are TV broadcast signals, WiFi signals, cellular, microwave data transmissions, satellite — you name it.

Most of you are probably far too young to remember crystal radio kits. Well, I’m approaching ‘older than dirt’ territory, and so I recall very well the day I bought my first one from Radio Shack and eagerly put it together. (At the age of 6, I was allowed to handle a soldering iron, but only with supervision.) Crystal radios use the power of the radio signal itself to run the device and produce sound in a small earpiece.

Imagine if you will taking ambient EM signals and using them to power an electronic device that converts it into a completely different transmitted signal.

As lead researcher at UW, Shyam Gollakota, describes it, his team’s technique uses a method called “ambient backscatter.” These small devices (about which you can learn more at this link right here) take the energy generated from reflected (backscattered) signals to transmit information.

University of Washington - Backscatter Devices

University of Washington — Ambient Backscatter devices (from their video here)

For their prototypes, they tuned them to use TV broadcast signals for power.

The researchers tested the ambient backscatter technique with credit card-sized prototype devices placed within several feet of each other. For each device the researchers built antennas into ordinary circuit boards that flash an LED light when receiving a communication signal from another device.


They found that the devices were able to communicate with each other, even the ones farthest from a TV tower. The receiving devices picked up a signal from their transmitting counterparts at a rate of 1 kilobit per second when up to 2.5 feet apart outdoors and 1.5 feet apart indoors. This is enough to send information such as a sensor reading, text messages and contact information.

The team also thinks it might be possible to scale this for cell phones so that enough power to transmit text messages could be generated, even with a totally dead battery. (My guess is they’d need to be simple, predetermined messages, such as an emergency call for help, because there wouldn’t be enough power to run the phone display.)

One of the applications they demonstrate in their video (embedded below) is wireless transactions between two of the backscatter devices.

Their prototype and the associated research (PDF at the link) won the best paper award on 13 Aug 2013 at the Association for Computing Machinery’s conference in Hong Kong.

I truly think Tesla would’ve loved this invention — a device that uses no energy, save that which is already in the air from other sources. His ideal was a world where there were no telegraph or telephone poles, no electrical transmission wires or conductors, except at the device level. Here’s another example of how visionary the man was:

“When wireless is perfectly applied the whole earth will be converted into a huge brain, which in fact it is, all things being particles of a real and rhythmic whole. We shall be able to communicate with one another instantly, irrespective of distance. Not only this, but through television and telephony we shall see and hear one another as perfectly as though we were face to face, despite intervening distances of thousands of miles; and the instruments through which we shall be able to do his will be amazingly simple compared with our present telephone. A man will be able to carry one in his vest pocket.”

Nikola Tesla interview by John B. Kennedy in 1929


In closing (and off-topic): John Aravosis has made a terrible, terrible mistake: Me.

Some of you who’ve made it this far down a somewhat wonky science post may have noticed a new name at the top and bottom. And some might see that name and worry whether this author is the same ‘BeccaM’ who’s been an obsessively prolific (and long-winded) AMERICAblog commenter for a while now. Alas, sadly, it is true. She is me. John ignored his better judgment (I suspect it’s all that rich French food he’s been enjoying while on his trip) and asked me to become a regular contributor.

I hope it takes me at least as long to destroy AMERICAblog as it did for John Oliver to ruin The Daily Show. Y’know, give John time enough to find a respectable replacement gig or to have Chris in Paris formally adopt him.

Although I’ve been particularly active on LGBT issues posts, I’m planning to write on a wide variety of topics, both serious and ‘fun.’ On my list are women’s issues, civil rights in general, technology and science, and pretty much anything I run across on the Intertoobz that I find interesting. Like this, for instance — it’s science, technology, and cool.

Published professional writer and poet, Becca had a three decade career in technical writing and consulting before selling off most of her possessions in 2006 to go live at an ashram in India for 3 years. She loves literature (especially science fiction), technology and science, progressive politics, cool electronic gadgets, and perfecting Hatch green chile recipes. Fortunately for this last, Becca and her wife currently live in New Mexico. @BeccaMorn

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