Researchers 3D-print WiFi-connected objects that don't need power

The objects contain antennas that reflect surrounding WiFi signals.

Researchers at the University of Washington have developed a way for 3D-printed plastic objects to transmit information via WiFi without the help of batteries or electronics. And they show that it can be done with commercially available plastics and WiFi receivers. "Our goal was to create something that just comes out of your 3D printer at home and can send useful information to other devices," Vikram Iyer, a graduate student on the project, said in a statement. "But the big challenge is how do you communicate wirelessly with WiFi using only plastic? That's something that no one has been able to do before."

To do this, the team used things like 3D-printed springs, gears and switches that could be used to translate motion into antenna-transmitted information. For example, they created an anemometer, which measures wind speed, and attached it to a gear. When the gear spins, the teeth connect with an antenna embedded into the object and that antenna then reflects ambient WiFi signal, which can be decoded by a WiFi receiver. The faster the wind, the faster the gear spins and the more rapidly those signals are transmitted. They also created a scale and a flowmeter that can measure water speed.