We often hear about the breakthroughs of scientists who are about to change our lives. But in many cases we are dealing with novelties whose implementation on a production scale would be incredibly expensive and not always cost-effective. However, the researchers at Dartmouth College have developed an interesting way to effectively enhance home Wi-Fi networks which rely on aluminium foil. Sounds like a typical clickbait, but it really works.

The method developed by researchers from Dartmouth College in the United States is based on the well-known in radiocommunication principle of electromagnetic wave reflection and their concentration. This may sound complicated, but this idea is used, for example, in parabolic antennas that are commonly used to receive satellite TV. The problem with such antennas is that they are large, so they can not be used in Wi-Fi networks. Of course there are plenty of recordings on the Internet showing how to build simple reflector for home routers. But scientists show that conventional approach to the problem do not provide the best results. That’s why they decided to solve the problem in a slightly different way and have written a program that optimizes the shape of the reflector for Wi-Fi routers.

Researchers have been working on Wi-Fi reflectors for over 2 years.

The first results of the study were presented at the HotWireless 2015 conference, where researchers were rewarded. A few days ago, at the BuildSys conference in the Netherlands, they have published a paper which describes a refined version of the algorithm. For 2 years the researchers have worked out:

  • a method for quickly calculating the radiation characteristics of a Wi-Fi router with a reflector,
  • an indoor propagation model that takes into account wall attenuation,
  • algorithm to optimize the shape of the reflector.

Project assumptions are quite interesting. The inputs are: a room plan, a Wi-Fi router location, and a list of places where the Wi-Fi signal should be amplified and where it has to be low. Exactly, the use of a specially shaped headlamp not only “amplifies” the signal in selected rooms, but also limits the range of our Wi-Fi network in selected directions. This may be an interesting practical application for Wi-Fi security. For example, we can make sure none of the neighbours will connect to our router because they will not receive the signal coming from it. Custom-made reflectors are manufactured using a 3D printer. The process lasts 23 minutes, and the materials cost $35.


  • WiPrint project
  • Xi Xiong, Justin Chan, Ethan Yu, Nisha Kumari, Ardalan Amiri Sani, Changxi Zheng, and Xia Zhou. Customizing Indoor Wireless Coverage via 3D-Fabricated Reflectors, ACM International Conference on Systems for Energy-Efficient Built Environments (BuildSys), November, 2017, Delft, The Netherlands. [PDF]
  • Justin Chan, Changxi Zheng, and Xia Zhou. 3D Printing Your Wireless Coverage, ACM Workshop on Hot Topics in Wireless (HotWireless), September, 2015, Paris, France. Hot Paper Award. [PDF]