Researchers from that university have announced the creation of the first 3D printed plastic objects and sensors able to collect useful data and communicate with other WiFi devices on their own. In this case, the antenna is contained in a 3-D printed object made of conductive printing filament that mixes plastic with copper.
What this means is that the researchers can turn non-electrical items into handy WiFi-connected tools: a laundry detergent lid that detects when you're out of soap (and places an order for a replacment), a battery-free slider that controls music volume, or a button that automatically places an online order for food, for example.
Vikram Lyer, co-lead author, said: "The big challenge [was] how do you communicate wirelessly with WiFi using only plastic? That's something that no one has been able to do before".
The secret to these unusual plastic objects is the use of backscatter techniques, which allow devices to exchange information. It typically relies on electronic components to reflect or absorb radio signals from a Wi-Fi router.
Physical motion triggers gears and springs elsewhere in the 3D printed object that cause a conductive switch to intermittently connect or disconnect with the antenna and change its reflective state.
The printed gear system encodes the 0s and 1s via the presence or absence of teeth in a plastic cog. Energy from a coiled spring drives the gear system, and the width and pattern of gear teeth control how long the backscatter switch makes contact with the antenna, creating patterns of reflected signals that can be decoded by a WiFi receiver. "The interaction between the 3-D printed switch and antenna wirelessly transmits that data", said Shyam Gollakota, an associate professor in the Paul G. Allen School of Computer Science & Engineering.
The researchers also used an iron filament to create magnetic properties and embed information into objects, which could include barcodes or information that tells a robot how to interact with the objects. They also 3D printed a test tube holder that could help manage inventory or measure the amount of liquid in each test tube, as well as a series of buttons, knobs and sliders that can be customized to communicate with other smart objects.
The research paper, "3D Printing Wireless Connected Objects", was authored by Iyer, Gollakota, and Justin Chan.