3D-Printed Plastic Objects Send Data Over Wi-Fi Without Any Electronics

3D printing can be useful if you need a simple object or a replacement part, but making anything complex usually requires you add some non-printed materials. A team from the University of Washington has shown that isn’t necessarily the case anymore. They’ve created 3D printed plastic objects that are Wi-Fi enabled and don’t require any added electronic components.

Finding practical uses for basic consumer 3D printing has been a challenge, and this has definitely slowed adoption of the technology. Although, maybe we just haven’t hit upon the right designs yet. The UW team wanted to see if it was possible for a plastic object from a printer to send useful data over Wi-Fi, and that seems like it could be quite useful. The result of that work is a fascinating gear and spring system that turns physical movement into electronic data on a Wi-Fi network.

The team created several versions of the gear and spring contraption, which is essentially a wireless sensor. Most of the object is standard plastic, but there’s also an “antenna” composed of conductive filament. Again, this is 3D printed, so there’s no cheating going on here.

So, how does it work? There’s no battery — we still can’t print those — but the coiled spring provides all the energy needed to transmit data. The gear has teeth that encode 1s and 0s. As it spins, it pushes a contact on the end of the spring to make contact with the antenna. The printed sensor doesn’t need to actually connect to your Wi-Fi network to transmit data. Instead, it reflects ambient wireless signals in a way that can be detected by a Wi-Fi receiver. This “backscatter” signal is decoded by a device like a phone or computer to determine how fast the gear is spinning.

Researchers created a few examples of 3D printed devices that could send data to other connected devices without any internal electronics. There’s a wind meter, a water flow meter, and a scale. The technique was also applied to simple input devices. The team created a button, a slider, and a knob, all of which can interact with an electronic device. For example, you could 3D print a slider that changes the volume on your computer without any electronics.

The UW team used a somewhat spendy MakeIt Pro 3D printer, which retails for just shy of $3,000. You don’t need anything that extravagant, though. All the 3D models are available for download if you want to build your own plastic Wi-Fi devices.