Worldwide studies are underway on the batteries of the future, but today you can influence existing technology to power electronic devices. In addition to radio signals at high frequency, you could in fact use the widespread standard for wireless networks. Researchers at the University of Washington (Seattle) have urbanized a system, called Power over WiFi (PoWiFi) which allows providing power to various types of devices and sensors for the Internet of Things (IoT).
A WiFi router is commonly used to send data to mobile devices, but these transmissions are a form of energy that can be collected by antennas and converted to voltage. The US university team has made a test by connecting an antenna to a temperature sensor, positioned next to the router. Unfortunately, the value never reached the in service threshold of 300 milli volts, because the data transmission does not takes put continuously. When you stop, the voltage decreases and the sensor are not powered.
However, the researchers found the answer. Using three router with chips, properly programmed, they sent noise along with data on different channels WiFi, avoiding interference. It was therefore generated a continuous signal that has allowed to supply the sensor temperature from a distance of six meters. Adding a rechargeable battery can reach nine meters.
With two other experiments, the researchers were able to feed camera surveillance to five meters away and recharge up to 41% fitness tracker Jawbone UP24 in about 2.5 hours. Technology wifi signal could make a significant contribution to the spread of the Internet of Things, as devices and sensors would not need its own power source.