Researchers have made plastic gears and switches that reflect ambient WiFi.
Researchers at the University of Washington have come up with a way to 3D print objects that can connect to WiFi networks without the use of batteries or other power sources. Creating a number of gears, switches and springs, the team was able to show how little more than plastic could be needed to create a WiFi-enabled water meter, audio slider or way to automatically order products on Amazon.
“Our goal was to create something that just comes out of your 3D printer at home and can send useful information to other devices,” said electrical engineering doctoral student Vikram Iyer, 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.”
Borrowing from principles that allow battery-free watches to keep time, the researchers set out to replace functions performed by electronic components with mechanical parts. At the core of their efforts is a set of gears attached to a 3D-printed antenna, made from conductive plastic. The movements of the gears activate the antenna, which encodes contact information in the form of 1s and 0s.
This “backscatter data” reflects ambient WiFi signal, and can be decoded by a commercially available WiFi receiver. This allows the system to communicate information about, for example, how fast the gears are turning and therefore how fast a connected process is occurring.
“As you pour detergent out of a detergent bottle, for instance, the speed at which the gears are turning tells you how much soap is flowing out,” said Shyam Gollakota, associate professor at Washington's Paul G. Allen School of Computer Science & Engineering.
“The interaction between the 3-D printed switch and antenna wirelessly transmits that data. Then the receiver can track how much detergent you have left and when it dips below a certain amount, it can automatically send a message to your Amazon app to order more.”
As their paper on the research explains, the team also experimented with printing conductive material into 3D objects, which can carry specific information. It may be the case this setup is used to provide details about an object's history when it is scanned by a smartphone, or gives a robot information about what it is supposed to do with the object.
The researchers have made their 3D models available to the public. If you have a 3D printer and some conductive plastic lying around, you can try making your own WiFi connected gizmo.
Images: Mark Stone/University of Washington