Is this something I could feasibly accomplish?
Passive RFID transponders receive energy from a reader antenna and store it briefly in a capacitor, then use that energy to respond to the reader's commands. If you are looking to harvest energy for a non-RFID device, then I'm afraid I can't help you since I am not an engineer. I do know that a lot of research is being done around energy harvesting, though, so I would suggest you contact the IEEE, which can probably point you to some of the research going on in this field.
—Mark Roberti, Founder and Editor, RFID Journal