Engineer aims to connect the world with ant-sized radios

September 10, 2014 by Tom Abate
The tiny radio-on-a-chip gathers all the power it needs from the same electromagnetic waves that carry signals to its receiving antenna.

(Phys.org) —A Stanford engineering team has built a radio the size of an ant, a device so energy efficient that it gathers all the power it needs from the same electromagnetic waves that carry signals to its receiving antenna – no batteries required.

Designed to compute, execute and relay commands, this tiny wireless chip costs pennies to fabricate – making it cheap enough to become the missing link between the Internet as we know it and the linked-together smart gadgets envisioned in the "Internet of Things."

"The next exponential growth in connectivity will be connecting objects together and giving us remote control through the web," said Amin Arbabian, an assistant professor of electrical engineering who recently demonstrated this ant-sized chip at the VLSI Technology and Circuits Symposium in Hawaii.

Much of the infrastructure needed to enable us to control sensors and devices remotely already exists: We have the Internet to carry commands around the globe, and computers and smartphones to issue the commands. What's missing is a wireless controller cheap enough to so that it can be installed on any gadget anywhere.

"How do you put a bi-directional wireless control system on every lightbulb?" Arbabian said. "By putting all the essential elements of a radio on a single chip that costs pennies to make."

Cost is critical because, as Arbabian observed, "We're ultimately talking about connecting trillions of devices."

A three-year effort

Arbabian began the project in 2011 while he was completing a PhD program and working with Professor Ali Niknejad, director of the Wireless Research Center at the University of California, Berkeley. Arbabian's principal collaborator was his wife, Maryam Tabesh, then also a student in Niknejad's lab and now a Google engineer.

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Amin Arbabian, assistant professor of electrical engineering, talks about the ant-sized radio.

Arbabian joined the Stanford faculty in 2012 and brought a fourth person onto the team, Mustafa Rangwala, who was then a postgraduate student but is now with a startup company.

The work took time because Arbabian wanted to rethink radio technology from scratch.

"In the past when people thought about miniaturizing radios, they thought about it in terms of shrinking the size of the components," he said. But Arbabian's approach to dramatically reducing size and cost was different. Everything hinged on squeezing all the electronics found in, say, the typical Bluetooth device down into a single, ant-sized silicon chip.

This approach to miniaturization would have another benefit – dramatically reducing power consumption, because a single chip draws so much less power than conventional radios. In fact, if Arbabian's radio chip needed a battery – which it does not – a single AAA contains enough power to run it for more than a century.

But to build this tiny device every function in the radio had to be reengineered.

The antenna

The antenna had to be small, one-tenth the size of a Wi-Fi antenna, and operate at the incredibly fast rate of 24 billion cycles per second. Standard transistors could not easily process signals that oscillate that fast. So his team had to improve basic circuit and electronic design.

Many other such tweaks were needed but in the end Arbabian managed to put all the necessary components on one chip: a receiving antenna that also scavenges energy from incoming ; a transmitting to broadcast replies and relay signals over short distances; and a central processor to interpret and execute instructions. No external components or power are needed.

And this ant-sized radio can be made for pennies.

Based on his designs, the French semiconductor manufacturer STMicroelectronics fabricated 100 of these radios-on-a-chip. Arbabian has used these prototypes to prove that the devices work; they can receive signals, harvest energy from incoming and carry out commands and relay instructions.

Now Arbabian envisions networks of these radio chips deployed every meter or so throughout a house (they would have to be set close to one another because high-frequency signals don't travel far).

He thinks this technology can provide the web of connectivity and control between the global Internet and smart household devices. "Cheap, tiny, self-powered radio controllers are an essential requirement for the Internet of Things," said Arbabian, who has created a web page to share some ideas on what he calls battery-less radios.

Explore further: Renesas creates a near-field wireless communication with no battery use

More information: A power-harvesting pad-less mm-sized 24/60GHz passive radio with on-chip antennas Tabesh, M.; Rangwala, M. ; Niknejad, A.M. ; Arbabian, A. VLSI Circuits Digest of Technical Papers, 2014 Symposium on. DOI: 10.1109/VLSIC.2014.6858380

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15 comments

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ViperSRT3g
5 / 5 (1) Sep 10, 2014
I'm very curious to see where this technology goes. The novelty of knowing you can just stick it wherever you need it to go without a power source is almost magical.
Mike_Massen
5 / 5 (3) Sep 10, 2014
And with RFID type embedded identification as well you have the situation where everything connected could know where everything in that network is located, its functionality, its history etc
This makes for some interesting highly secure workplaces, storage, manufacture & distributed processing networks especially if we consider they are pennies now but could be fractions of a penny if an application were widespread enough to use billions over a large area etc...
Roj
1 / 5 (2) Sep 11, 2014
The barometer of success for interconnected transmitters at 24 billion cycles per second will be irradiating men's scrotums with 24 billion cycles per second, effectively microwaving men's balls, sterilizing the population with free WIFI & bith control.
Whydening Gyre
4.7 / 5 (3) Sep 11, 2014
Wow, Roj....
That was rather dire...
Sinister1812
not rated yet Sep 11, 2014
Nice tracking device there. That could collect a lot of data..
retrosurf
1 / 5 (3) Sep 11, 2014
Gawd, we are so screwed.
They can be dropped from the sky, in vast numbers.

They will not be used to promote human dignity and privacy.
Sinister1812
1 / 5 (1) Sep 11, 2014
They will not be used to promote human dignity and privacy.


Relax bro, I was just saying that they *could*. Didn't mean to upset you.
Murtagh
not rated yet Sep 11, 2014
Damn, that's *awfully* close to the "localizers" used in Vernor Vinge's "A Deepness In The Sky" (one of the best science fiction novels of all time by the way).
alfie_null
5 / 5 (1) Sep 11, 2014
More specs on bandwidth and computing capability would be useful.

Per Shannon, the information carrying capacity of the communication links is influenced by the dynamic range of the channels. Given the low power of the transmitters, probably pretty limited for these devices.

Re scrotum angst: tissue penetration at 24 GHz is low. Much lower still at 60 GHz.
antialias_physorg
5 / 5 (1) Sep 11, 2014
Now Arbabian envisions networks of these radio chips deployed every meter or so throughout a house

Mix them in with the paint on your walls?

at 24 billion cycles per second will be irradiating men's scrotums with 24 billion cycles per second, effectively microwaving men's balls,

Erm. You do know what power levels we're talking about, here?

Nice tracking device there.

That's sort of the downside. With the appropriate receiving device you could gather all the information in a nearby apartment/house. So I'd rather we think about appropriate uses (and encryption/security) first before just sticking this stuff on everything.
GalaxyDrifter
1 / 5 (2) Sep 11, 2014
Never fear my fellow Americans.
These invading unwelcome vermin operate on very low powered RF waves.
How long would it take for one of you smart guys to build a handheld very powerful but short range EMP burst sweeper? Walk into your house sweep over every square foot and fry them all in seconds. While you are at it go ahead and smash all the cameras on your smart devices so the Goobermunt cant spy on you.
Sinister1812
not rated yet Sep 12, 2014
Never fear my fellow Americans.


I'll tell you what. You test the security first and if it's safe and secure from being hacked then maybe I'll think about putting them everywhere.
OZGuy
5 / 5 (3) Sep 13, 2014
@sinister - NOTHING is safe and secure from being hacked if it has any form of input.
Sinister1812
not rated yet Sep 13, 2014
@OZGuy Yeah true, that's the worrying part. And these will be connected with everything else.
sdrfz
1 / 5 (1) Sep 14, 2014

Light switches are too reliable to be replaced by any electronic device. Who's been happy with computers in cars? Nobody! They cost too much, break too often, and are expensive to repair. Give me a non-computerized car anytime. It'll be the same with computerized light switches and refrigerators in houses. If it ain't broke, don't fix it.

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