Researchers at the University of Washington have combined 3D printing, conductive materials, and backscatter techniques to connect plastic objects and sensors to a wireless Wi-Fi network without using embedded electronics.
“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 co-lead author and UW electrical engineering doctoral student Vikram Iyer. “But the big challenge is how do you communicate wirelessly with Wi-Fi using only plastic? That’s something that no one has been able to do before.”
The system uses backscatter communication techniques to exchange information with Wi-Fi receivers. A system of springs, gears and switches are used to initiate most of the functions that would normally be handled by electronics.
The backscatter system uses an antenna to transmit data by reflecting radio signals emitted by another wireless device. The conductive switch in the object connects or disconnects intermittently as a result of physical motion (pushing a button, turning a knob, etc.).
“As you pour detergent out of a Tide bottle, for instance, the speed at which the gears are turning tells you how much soap is flowing out. The interaction between the 3D printed switch and antenna wirelessly transmits that data,” said senior author Shyam Gollakota, an associate professor in the Paul G. Allen School of Computer Science & Engineering. “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.”
The research team has made its CAD models available to the public so that others can test out the objects for themselves. The designs include a number of gears, antennas, springs, switches and a flow meter. According to the researchers, the parts can be used to create a battery-free volume slider, a water sensor or a “button that automatically orders more cornflakes from Amazon.”
The research team successfully tested several devices, including a wind meter, a water flow meter and a scale. They also created the aforementioned laundry soap flow meter and a test tube holder that could help manage inventory or measure liquid amounts in each tube.
The team also used a printing filament that includes plastic and iron to encode static information in the objects using magnetism.
The team’s findings were presented on Nov. 30 at the Association for Computing Machinery’s SIGGRAPH Conference and Exhibition on Computer Graphics and Interactive Techniques in Asia.
Source: University of Washington