2017 study shows 3D-printed foil shapes can direct or block Wi-Fi signals

Researchers demonstrated in a 2017 experiment that wireless network signals extend far beyond a building's physical walls. Their study presented a method to customize indoor Wi-Fi coverage using 3D-printed plastic shapes coated in common aluminum foil. These custom reflectors, positioned around a router's antennas, could be computationally designed to strengthen or weaken signals in specific target areas. The technique showed signal strength could be adjusted by several decibels in controlled tests. This research highlights the potential to engineer a network's radio footprint as a possible security or performance measure.