We've seen all kinds of medical implants over the years, but none that had a musical preference -- until now. Researchers at Purdue University have created a pressure sensitive microelectromechanical system (MEMS) that uses sound waves as an energy source. The proof-of-concept has a vibrating cantilever that's receptive to sound -- or music -- in the 200 - 500Hz frequency spectrum, which is towards the bottom end of the audible range. The subcutaneous implant converts the low-frequency vibrations into energy, and then stores it in a capacitor. Once the cantilever stops vibrating, it sends an electrical charge to a sensor and takes a pressure reading, the result is then transmitted out via radio waves for monitoring purposes. The immediate real world applications include diagnosing and treating incontinence, but we're already wondering if that self-powering mp3 player implant could finally become a reality?