" By culling energy from existing radio, TV, and wireless signals, they've developed a way to connect low-energy devices, such as sensors and wearables, to the Internet without the need for batteries or power cords."
Hey! I just mentioned that idea a week ago in a comment! How did they develop it so fast?
Just kidding--obviously they came up with idea before me. This would be great for stress sensors on bridges and buildings. They are very low-power and low speed, so they need almost no power. They could slowly build up enough energy to be able to send out their data when needed.
Idea sounds brilliant. Challenge is how much can be drawn from WiFi signal that is intended for other purpose. Would it make more sense to draw power from other means such as solar or thermo? On the other hands, for indoor use, I am not too sure energy harvesting is crucial to the future of IoT. I can see outdoor IoT definitely demands energy harvesting though.