Nanotech powers this super-sensitive microphone

The trouble with microphones is that they don't just hear -- they have to listen. Powering the mic and its signal processor means using energy, and energy means a battery, and a battery means charging. This new microphone-like system hears more like the way our own ears do, requiring little or no power, and could help fill the world with voice-responsive machines. (If that's something we really want.)