An invention which converts WiFi signals into electricity

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Researchers from MIT have just presented the first completely flexible device that is able to convert energy from WiFi signals into electricity.  This new invention gives us an insight into many other possible devices which could be created in the future. 

Electronic properties of two-dimensional materials are the future of flexible electronics. Their atomic thickness could help to develop “smart films” capable of turning any object into a true electromagnetic wave sensor (like Wi-Fi) to transform these waves into electricity. Many components today are able to recover this energy and convert it, but they are all rigid. A flexible device, on the other hand, would allow a maximum surface coverage. This is why this new inventions is a step forward for this type of technology.

Transforming WiFi into an alternating current

Devices that convert electromagnetic waves into alternating currenst are called “rectennas”, or “rectifying antennas”. An MIT team explains in a recent study that they have developed a new device of this kind which uses a flexible RF antenna capturing electromagnetic waves, including those equipped with WiFi. The antenna is then connected to a two-dimensional  semiconductor which is three atoms thick. The signals then flow through the semiconductor, which converts them into an alternating current.
We have developed a new way to power the electronic systems of the future by harnessing Wi-Fi energy,” said Tomás Palacios, co-author of this new study published in Nature. This new device would currently be able to produce about 40 microwatts of power once exposed to the typical Wi-Fi signal power levels (about 150 microwatts).
Credits: Wikipedia

Many application would be possible

The energy this new device is able to produce (40 microwatts) is not much.  It would only be enough to illuminate a small mobile screen. However, in the long run, other applications using this technology seem very promising. As the material is flexible, the device could cover large areas a bit like a protective film – and then recover the surrounding electromagnetic energy to turn it into electricity. This current could then feed many electronic devices.

Researchers also believe that these flexible devices could be used for medical purposes. For example,  pills can be swallowed by patients that can now transfer their health status data to a computer. But there is a problem. “Ideally, you would not want to use batteries to power these systems as the patient could die if there was a lithium leakage, explains Jesús Grajal, researcher at the Technical University of Madrid (Spain). It is therefore better to recover energy from the environment to feed small laboratories located inside the body that can then communicate their data to external computers.

This is just a start to this type of technology. Researchers now plan to develop more effective devices. In the end, we could live in a world where smartphones, laptops and other electronic devices would never need to be recharged by us again.


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