There are various ways that can be used to generate electricity to power up mobile device but the recent announcement from Nokia may open up your mind. The Nokia Research Centre located in Cambridge, UK is designing a new prototype that is able to convert ambient electromagnetic radiation from phone antenna, or other RF wave source to electricity so that the mobile device can be continuously powered up for longer talk time without the need of recharging.
The mechanism behind is quite similar to what being deployed by current RFID (Radio Frequency Identification) but its usage has been expanded to more interesting application. Besides its own generated electromagnetic wave, the device can detect any other radiation sources such as WiFi devices, cordless phones in surrounding area for more effective power conversion. Currently, the prototype is claimed to be able to convert 3 to 5 miliwatts of electricity. Although it is still far from 50 miliwatts target required to sustain the mobile device in normal operation, but the brilliant concept is definitely a good start to trigger more development improvements as part of the efforts towards greener environment besides bringing convenience to end users.
While there are some technology obstacles that need to be tackled, the Finland based company is confident that the next generation energy harvesting technology should reach market space by three to four years time from now.