Assistive Technology Lets 3D-Printed Parts Communicate Wirelessly

University of Washington researchers develop device that tracks how 3D-printed objects are used without batteries or electronics.

The world of 3D printing has quickly expanded into many realms thanks to it being a cost-efficient and customizable method of production. Health care is one of those industries. As more printed plastic parts, such as prosthetics and smart pill dispensers, are being produced this way, there is one underlying issue: plastic parts lack electronics for monitoring.

Engineers at the University of Washington’s Paul G. Allen School of Computer Science & Engineering have developed an assistive technology that can track and store data without relying on batteries or electronics. The team turned to a method called backscatter to make it happen. The device communicates data by reflecting signals transmitted to it with an antenna.

The University of Washington team leading the 3D-printed wireless analytics project includes, from left, Vikram Iyer, Shyam Gollakota, Jennifer Mankoff, Ian Culhane and Justin Chan. (Image courtesy of Mark Stone, University of Washington.)

The University of Washington team leading the 3D-printed wireless analytics project includes, from left, Vikram Iyer, Shyam Gollakota, Jennifer Mankoff, Ian Culhane and Justin Chan. (Image courtesy of Mark Stone, University of Washington.)

“Using plastic for these applications means you don’t have to worry about batteries running out or your device getting wet. That can transform the way we think of computing,” said senior author Shyam Gollakota, associate professor. “If we really want to transform 3D-printed objects into smart objects, we need mechanisms to monitor and store data.”

The latest announcement comes on the heels of the team’s previous work, which included developing 3D-printed objects able to connect to Wi-Fi without electronics. This allowed them to address the first issue of monitoring. They were able to track movements in one direction, making it possible to measure wind speed and monitor the level of laundry detergent. The system was able to detect the bottle’s low level and automatically order more online.


After crossing that hump, they then focused on bidirectional monitoring. The newest device has two antennas attached to the top and bottom that can be contacted through a switch attached to a gear. In the case of opening a bottle, when the cap is moved to be opened, the gear moves in one direction. When closing, it moves in the opposite direction. Each time, the switch hits the antenna.

“The gear’s teeth have a specific sequencing that encodes a message,” said co-author and doctoral student Justin Chan. “It’s like Morse code. When you turn the cap in one direction, you see the message going forward. When you turn the cap in the other direction, you get a reverse message.”

The team sees this method being used to monitor prosthetics, like the 3-D printed e-NABLE arms. Designed for children with hand abnormalities, these mechanical hands attach at the wrist and assist with grasping objects. Flexing the wrist triggers cables on the hand to tighten and the fingers to close. The printed a prototype using their sensors to monitor movements.

3D-printed assistive technology could help monitor how prosthetics are used. (Image courtesy of Mark Stone, University of Washington.)

3D-printed assistive technology could help monitor how prosthetics are used. (Image courtesy of Mark Stone, University of Washington.)

“This system will give us a higher-fidelity picture of what is going on,” said Jennifer Mankoff, professor. “For example, right now we don’t have a way of tracking if and how people are using e-NABLE hands. Ultimately, what I’d like to do with this data is predict whether or not people are going to abandon a device based on how they’re using it.”

While these prototypes are encouraging, according to Mankoff, the team’s next step is to take these concepts and shrink them so that they can be embedded in real pill bottles, prosthetics or insulin pens.

Interested in more 3D printing innovations? Check out 3D Printing a Bionic Eye and Dog Receives 3D Printed Skull Implant in Pioneering Surgery.