Radio Waves: Alternative Power Source

Jul 20, 2010 by John Messina weblog
Radio Waves: Alternative Power Source
Using only radio waves for its electrical power, the SmartHat has a beeper that alerts the wearer to dangerous construction equipment nearby.
Credit: Jochen Teizer

(PhysOrg.com) -- Researchers at Duke University are harvesting ambient radio waves to power small microprocessor devices that consume very little energy. Devices such as sensors that monitor critical environmental changes can be powered from radio waves.

Dr. Matt Reynolds, an assistant professor at Duke University, heads the electrical and computer department. Matt has demonstrated a low power device that is fitted into a hard-hat. Called a SmartHat, the device sounds a beeper that warns when dangerous equipment is nearby on a construction site.

The radio waves are harvest from wireless network transmitters installed on backhoes and bulldozers; they are used to keep track of their location. The low power sensor is used to monitor the direction and strength of the and warns the hard-hat wearer if they are too close.

Matt and his associates are inventing devices that consume so little power that batteries aren’t require to run them. Ambient radio waves are sufficient to operate these devices equipped with low power microprocessors.

Powercast is a company that sells radio wave transmitters and receivers that use radio waves to operate low power devices. The company recently released a receiver for charging battery-free wireless sensors; the receiver powers modules that include microcontrollers from Microchip Technology.

Because radio waves spread and lose their energy rapidly, this technology hasn’t been explored very much. With the recent advancements in , tiny amounts of electricity can now be made to do useful work.

At Intel, Dr. Smith is exploring the use of and creating an electronic "harvester" of ambient . The harvester collects enough energy from a TV station that’s approximately 2.5 miles from the lab to run a temperature and humidity sensor. The device collects enough power to produce about 50 microwatts of power that’s sufficient to operate many sensors. In comparison a solar powered calculator only consumes about 5 microwatts.

Dr. Reynolds of Duke University stated: “We are on the cusp of an explosion in small wireless devices than can run on alternatives to battery power. Devices like this can live on and on."

Explore further: PsiKick's batteryless sensors poised for coming 'Internet of things'

More information: Powercast
Via: NY Times

Related Stories

Imec achieves breakthrough in battery-less radios

Feb 09, 2010

At today's International Solid State Circuit Conference, Imec and Holst Centre report a 2.4GHz/915MHz wake-up receiver which consumes only 51µW power. This record low power achievement opens the door to battery-less ...

MEMS device generates power from body heat

Apr 29, 2010

(PhysOrg.com) -- In an attempt to develop a power source that is compact, environmentally friendly, and has an unlimited lifetime, a team of researchers from Singapore has fabricated an energy harvesting device ...

Random Antenna Arrays Boost Emergency Communications

Feb 25, 2009

(PhysOrg.com) -- First responders could boost their radio communications quickly at a disaster site by setting out just four extra transmitters in a random arrangement to significantly increase the signal power at the receiver, ...

Recommended for you

Large streams of data warn cars, banks and oil drillers

Apr 16, 2014

Better warning systems that alert motorists to a collision, make banks aware of the risk of losses on bad customers, and tell oil companies about potential problems with new drilling. This is the aim of AMIDST, the EU project ...

User comments : 2

Adjust slider to filter visible comments by rank

Display comments: newest first

langbaba
not rated yet Jul 21, 2010
Had a similar idea quite a few years back (still in school). The circuit I built took about 4 components and powered a small LED light while close to a RF source (CRT screen worked quite well ;-).
I always had this idea of building a thousand of these devices and connecting their output together, thus providing enough power to charge a battery ...
Yes, have a look at a basic crystal radio - that's where my ideas originally came from if I remember correctly!
trekgeek1
not rated yet Jul 29, 2010
Seems like such a low power system could have energy harvested from the motion of the human body just as easily without having an RF source nearby. Most hard hats have the outer shell and an inner "net" that sits on your head and provides a shock absorbing feature. Placing piezoelectric materials at these junctions would probably accomplish the same task.

More news stories

Venture investments jump to $9.5B in 1Q

Funding for U.S. startup companies soared 57 percent in the first quarter to a level not seen since 2001, as venture capitalists piled more money into an increasing number of deals, according to a report due out Friday.

Hackathon team's GoogolPlex gives Siri extra powers

(Phys.org) —Four freshmen at the University of Pennsylvania have taken Apple's personal assistant Siri to behave as a graduate-level executive assistant which, when asked, is capable of adjusting the temperature ...

White House updating online privacy policy

A new Obama administration privacy policy out Friday explains how the government will gather the user data of online visitors to WhiteHouse.gov, mobile apps and social media sites. It also clarifies that ...

Scientists tether lionfish to Cayman reefs

Research done by U.S. scientists in the Cayman Islands suggests that native predators can be trained to gobble up invasive lionfish that colonize regional reefs and voraciously prey on juvenile marine creatures.

Leeches help save woman's ear after pit bull mauling

(HealthDay)—A pit bull attack in July 2013 left a 19-year-old woman with her left ear ripped from her head, leaving an open wound. After preserving the ear, the surgical team started with a reconnection ...