Interesting article about using the energy from the AM and FM radio stations to power a sensor. I think the key technologies for the future will be using the summing of waves to move things really small distances or change properties of light and sound. And the other key feature is tapping into the resonant frequency of materials.

I have been thinking about the power of resonance ever since I saw the Tacoma Narrows bridge disaster (1:25 into the video), which I feel every engineering student saw at some point. There must be cool ways to leverage resonance.