The guys at Instructables came up with a chest harness to generate power for USB devices. Maybe they’ll give new meaning to the term wonderbra.
Using some high-ratio gear motors this â€œthorax expansion couplerâ€ uses your body motion for regular breathing. Although the instructions to build such a device are a little taxing, it would be a fun gear-head project.
The goal of the chest USB charger would be generating about 500mW and in the enclosure size of a cell phone. The picture above is only a proof of concept and gets just a little over 50mW of power. At that rate, it would take about a day to charge one AA battary.