Capturing Otherwise Lost Wireless Energy
Right now there is a good chance a great deal of radiation is passing through each of us, from wireless routers and cell phone towers. Sadly, there is a good chance that much of that energy passing through us is going to be lost. Researchers at Duke University though have a new device to hopefully harvest that energy, and put it to use.
While most people will associate the photoelectric effect with solar panels that capture visible light, it applies to the larger electromagnetic spectrum, including the microwaves used for wireless communication. Using metamaterials, which have optical properties impossible to find in Nature, the researchers were able to build a device to capture and convert wasted wireless energy into a direct current. When tested the device was able to reach an impressive 37% efficiency and produced 7.3 V of energy.
An important aspect of the device's design is that it can be easily extended to capture more energy. It should also be possible to modify it to fit within cell phones and other devices, in order to wirelessly charge them when an outlet is not available.
Source: Duke University