Engineers at Stanford University have developed a tiny radio that’s 
about as big as an ant and that’s cheap and small enough that it could 
help realize the “Internet of things”—the world of everyday objects that
 send and receive data via the Internet.
 
The radio is built on a piece of silicon that measures just a few 
millimeters on each side. Several tens of them can fit on the top of a 
U.S. penny and the radio itself is expected to cost only a few pennies 
to manufacture in mass quantities.
 
Part of the secret to the radio’s size is its lack of a battery. Its 
power requirements are sufficiently frugal that it can harvest the 
energy it needs from nearby radio fields, such as those from a reader 
device when it’s brought nearby.
 
RFID tags and contactless smartcards can get their power the same way, 
drawing energy from a radio source, but Stanford’s radio has more 
processing power than those simpler devices, a university representative
 said. That means it could query a sensor for its data, for instance, 
and transmit it when required.
 
The device operates in the 24GHz and 60GHz bands, suitable for communications over a few tens of centimeters.
 
Engineers envisage a day when trillions of objects are connected via 
tiny radios to the Internet. Data from the devices is expected to help 
realize smarter and more energy-efficient homes, although quite how it 
will all work is yet to be figured out. Radios like the one from 
Stanford should help greatly expand the number of devices that can 
collect and share data.
 
The radio was demonstrated by Amin Arbabian, an assistant professor of 
electrical engineering at Stanford and one of the developers of the 
device, at the recent VLSI Technology and Circuits Symposium in Hawaii.