The amount of energy harvested thru these methods is ridiculously small except for the green wheel. You're better off putting a rechargable watch battery into devices along with wireless charging circuitry than use these methods. The exception being research into implantable pacemakers that never need removing.
Energy harvesting seems to be one of the next big thing in 2013. I wonder whether the energy is being harvested is actually needed elsewhere. Harvesting from breathing and body heat would probably has no side effect to the person. I would like to understand more about "Harvesting vibrations from heartbeats", etc.
Wearable human motion energy harvester
A Book For All Reasons Bernard Cole1 Comment Robert Oshana's recent book "Software Engineering for Embedded Systems (Newnes/Elsevier)," written and edited with Mark Kraeling, is a 'book for all reasons.' At almost 1,200 pages, it ...