Power Generation by Harvesting Ambient Energy with a Micro- Electromagnetic Generator

摘要

This thesis investigated the potential power output of micro-electromagnetic generators fabricated using typical microfabrication materials and techniques. The design was intended to eliminate the need for batteries in bio-implanted or remote electronic devices. Such a micro-generator could harvest ambient energy and power such devices indefinitely. Using electromagnetic theory, designs for the magnet's stator coil and rotor magnets were optimized to produce maximum current density. A method for overlaying two evaporated gold wires was devised and successfully fabricated in order to avoid side-wall thinning of the conductive coils. Once fabricated, the ferromagnetic nickel rotors were magnetized with an electromagnet. Testing of the magnets showed that the nickel rotors were able to be highly magnetized when placed near a strong yield, but, upon removal from the yield, the magnetization quickly dissipated. It was determined that the coercivity of electroplated nickel was too low for the rotor magnets to retain a yield for any appreciable amount of time. Testing of the micro-generator revealed that power output did not exceed 2 nA, thus nickel does not maintain the ux density required for such a generator and different materials should be investigated.