Scientists have invented a device that collects errant microwave signals from the air and converts them into electrical current capable of charging a cell phone. <br /><br />Researchers at Duke University said the device has nearly the same efficiency as solar panels. <br /><br />The device consists of a series of five fiberglass and copper conductors wired together on a circuit board to convert microwaves into 7.3V of electricity. USB chargers for small electronic devices provide about 5V.<br /><br /> "We had been getting energy efficiency around 6 to 10 percent, but with this design we were able to dramatically improve energy conversion to 37 percent." said engineering student Allen Hawkes.<br /><br />The small amount of energy generated from these signals might power a sensor network in a remote location or remote environments such as a mountaintop or in a desert. <br /><br />Future versions of this device will be able to harvest signals from a range of sources such as satellite, sound or Wi-Fi .<br /><br />The invention that provides a simple and inexpensive approach to electromagnetic power harvesting was created by undergraduate engineering student Allen Hawkes, graduate student Alexander Katko and lead investigator Steven Cummer.
