Cheap, Flexible, Battery-Free Tags to Control Your IoT Devices

The Internet of Things is a bit of a double-edged sword. On the one hand, outfitting your home with IoT devices can make a lot of tasks more convenient. But, on the other hand, IoT devices get expensive quickly when every device and control needs a microcontroller and WiFi capability. These new smart tags could, potentially, reduce that cost dramatically by providing control with simple, incredibly inexpensive, printable circuits.

The LiveTag circuits are printed in thin copper foil on a flexible substrate similar to paper. The circuits themselves are incredibly simple, and would cost just pennies per piece to manufacture at a large scale. They work by modifying and reflecting the WiFi radio waves being emitted by your router. When you touch part of the circuit it’s either connected, like a switch, or the resistance changes, and the radio waves being reflected back to the router are changed and can be registered. The same concept could be also be used with Bluetooth and cellular signals.

To demonstrate LiveTag, the team created an IoT music player controller that has buttons for play/pause and next track, along with a slider for volume control. A WiFi remote with comparable controls would cost at least a few dollars, but this chip-free circuit would cost just cents. It’s also thin and flexible enough to be placed on any object. However, LiveTag is severely limited by range right now, and tags need to be within three feet of the router. The LiveTag team hopes to eventually improve that range in order to make it practical for use throughout your home.