World's first technology that can connect battery-free devices to Wi-Fi
Scientists
have created the world's first technology that can connect battery-free devices
to Wi-Fi.
University
of Washington says a world will soon become a reality where your wristwatch or
other wearable device will communicate directly with your online profiles,
storing information about your daily activities where you can best access it -
all without requiring batteries. Or maybe battery-free sensors embedded around
your home could track minute-by-minute temperature changes and send that
information to your thermostat to help conserve energy.
The
university engineers have designed a new communication system that uses radio
frequency signals as a power source and reuses existing Wi-Fi infrastructure to
provide Internet connectivity to these devices.
Sensors
could now be embedded in everyday objects to help monitor and track everything
from the structural safety of bridges to the health of your heart. But having a
way to cheaply power and connect these devices to the Internet has kept this
from taking off.
"If
such devices are going to take off, we must provide connectivity to the
potentially billions of battery-free devices that will be embedded in everyday
objects," said Shyam Gollakota, a UW assistant professor of computer
science and engineering. "We now have the ability to enable Wi-Fi
connectivity for devices while consuming orders of magnitude less power than
what Wi-Fi typically requires."
This
work builds upon previous research that showed how low-powered devices such as
temperature sensors or wearable technology could run without batteries or cords
by harnessing energy from existing radio, TV and wireless signals in the air.
This work takes that a step further by connecting each individual device to the
Internet, which previously wasn't possible.
The
challenge in providing Wi-Fi connectivity to these devices is that
conventional, low-power Wi-Fi consumes three to four orders of magnitude more
power than can be harvested in these wireless signals.
The
researchers instead developed an ultra-low power tag prototype with an antenna
and circuitry that can talk to Wi-Fi-enabled laptops or smartphones while
consuming negligible power.
These
tags work by essentially "looking" for Wi-Fi signals moving between
the router and a laptop or smartphone. They encode data by either reflecting or
not reflecting the Wi-Fi router's signals, slightly changing the wireless
signal. Wi-Fi-enabled devices like laptops and smartphones would detect these
minute changes and receive data from the tag.
