A team of researchers at the Massachusetts Institute of Technology have discovered a very unique and extraordinary way to produce electricity from ubiquitous Wi-Fi signals. They have made this possible by making the first device that can harness energy from Wi-Fi signals and convert that energy to electric power. Successful experiments conducted by the researchers prove that the device can produce about 40 microwatts of power, which is enough to power a smartphone display screen, from a typical Wi-Fi signal.
According to Tom?s Palacios (2019), a professor in the Department of Electrical Engineering and Computer Science, this energy can potentially be used to power electronic devices like smartphones, laptops and wearables without in-built batteries.
AC and DC are two kinds of electric signals, out of which only DC can be used to power electronic components. Wi-Fi signals consist of electromagnetic waves called radio waves. The researchers at MIT modified a device called rectenna to use radio frequencies and capture these radio waves in the Wi-Fi signals.
These waves can then be converted to DC signals with an electronic device called rectifier which is a part of the rectenna. Instead of using a traditional rectifier, which is a solid and rigid device, the researchers built their own by using a special chemical compound called molybdenum disulphide, which is the worlds thinnest (only three atoms thick) semiconductor. According to Zhang (2019), an assistant professor at Carnegie Mellon University, this has allowed the MIT researchers to fabricate the newly developed device into sheets of flexible plastic or metal foil.
The team is now working to improve the efficiency of the device to build power more complex components.
Relation with The Science of Everything
This news article relates to the second chapter titled Energy from the book Science Matters: Achieving Scientific Literacy by Robert Hazen and James Trefil. The chapter mentions that energy comes in a variety of forms and energy can be converted from one form to another. The researchers at MIT utilized this very fact and converted the radio signals into electric kinetic energy, which is the energy of moving electrons. The book also mentions that when such a conversion occurs, there is always a loss of energy in the form of heat. In order to improve efficiency, the researchers would have to minimize this loss. The article is also related to the chapter, Electricity and Magnetism which mentions the fact that Wi-Fi signals are radio waves which in turn are electromagnetic radiation.
Reading through the article, I did not understand the process of designing an electronic component into layers of flexible plastic or metal foil. According to Jeffrey Morse (2011), the managing director of National Nanomanufacturing Network, this process of manufacturing electronic circuits or components into sheets of metal is called roll-to-roll processing, web processing or R2R. In this technique, flexible electronic components are continuously processed and transferred between two moving rolls of metal or plastic. These devices are patterned onto these sheets in a manner similar to how a printer deposits ink on the paper. After processing these materials onto the rolls, the required size is cut into products. According to Alberto Salleo (2009), these rolls can be anywhere between a few meters to about 50 km. One of the major advantages of R2R is that overall, it reduces the manufacturing cost even though the initial installation cost can be higher. Electronic components like solar cells can best take advantage of this flexible nature of R2R manufacturing.
The development of this device is a significant step towards powering electronic devices without batteries. According to Tom?s Palacios (2019), this invention can potentially be used to cover an entire highway or a bridge to power up street lights. Foldable smartphones make a major application of this device as it can be manufactured using the R2R technique. According to Jes?s Grajal (2019), a researcher at the Technical University of Madrid, this device can also be used to develop oral pills which, once taken by the patient, can provide medical data of the body to local computers. Present day pills use lithium batteries but they can potentially kill the patient if the lithium leaks. Powering these pills through rectennas solves this problem.
One of the major reasons why I picked this article is because I find inventions of electrical and electronic devices very interesting. Currently, I am pursuing the Electrical Engineering program at Humber and reading through this news article has made me realize how this invention can change our perception of electronic devices. Now I am more aware of the options that I have for further education like pursuing a masters degree in Microelectronics Manufacturing Engineering. As far as my personal interests are concerned, it would very fascinating to use foldable smartphones in the near future.
Abazorius A. (2019, January 28). Converting Wi-Fi signals to electricity with new 2D materials. Retrieved from
Morse J. (2011, September 27). Nanofabrication Technologies for Roll-to-Roll Processing. Retrieved from
Wong, W. S., & Salleo, A. (2009). Flexible electronics: Materials and applications. Springer.