Ant-sized radio devices tested by Stanford engineers

A Stanford engineering team has built a wireless radio the size of an ant, which works without batteries. The device gets all the power it needs from the same electromagnetic waves that carry signals to its receiving antenna.
But to what use can this tiny device, costing just a few pennies be put to? It is designed to "compute, execute and relay commands" a Stanford statement said. Since it is so cheap to make, it has the potential 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 radio 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."
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. His team includes his wife, Maryam Tabesh, a Google engineer and Mustafa Rangwala, who is with a startup company.
Arbabian managed to put all the necessary components on one chip: a receiving antenna that also scavenges energy from incoming electromagnetic waves; a transmitting antenna 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.
Based on his designs, a French semiconductor manufacturer 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 radio signals and carry out commands and relay instructions. He 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).