These experiments were based off the idea of using an aluminum soda can behind a router in order to direct the signal away from deadening walls and other obstructions. The team was able to analyze a space and create a custom reflector that would optimize the WiFi signal in that room. They then fed their data into a custom program called WiPrint that designed an optimal plastic reflector and created it using a 3D printer. The last step is to cover the object in aluminum foil and place it on the router. You can see a demonstration in the video below.

This solution solves multiple problems with WiFi signals. First of all, it's inexpensive; if you have access to a 3D printer, it will only run you about $35. Directional antennas cost a lot more than that. Second, it allows you control over your WiFi signal, which has more benefits than you think. Not only does it make sure you have signal in the rooms you need it in, but it allows you to cut off signal where you don't. This improves physical security, ensuring neighbors (and unsavory types) can't access your network.

The next step for the team is to figure out how to design reflectors that are made of a different material than 3D printed plastic. The idea is to eventually create an object that can actually change shape if the room's layout changes. This may not expand the coverage area of your router, but it will ensure that you'll get stronger signal in the areas you need it most.