Mechanical devices, particularly 3D printed ones, don’t have much room for electronics and so they remain “dumb” in many ways. Electronics need a power source and integrating them within moving components that are already complex can create greater difficulties. Engineers at the University of Washington have now developed a simple way to make devices, such as prosthetic arms, rehab tools, and pill bottles, be able to self-report on their usage without having any electronics at all.
Their technology brings together specially created gears, simple antennas, and a nearby wifi router to be able to detect changes in the signals reflecting from the antennas inside the mechanical devices.
Some of the gears have teeth that can have different widths and may be positioned to encode things like how far a prosthetic arm is extended or how many times a pill bottle has been opened. As the gears click along, they trigger antennas within the device to touch other pieces of metal, changing how they reflect wifi signals. The wifi router detects this and so recognizes the information being sent from the mechanical device.
Here’s a great video with one of the engineers explaining the system: