1. Vulture Technologies Project Update 1 15 February 2007

2. Vibration Harvesting Device

3. Magnet Design:  Geometric configuration  transfer of vibrational energy from source to magnet Source: Donations from Prof. O'Handley and/or Prof. Ross Type: Powerful, probably rare earth (NdFeB)

4. Magnetostriction “Deformation of a body in response to a change in its magnetization.” Engdahl, G. (2000). Handbook of Giant Magnetostrictive Materials. San Diego: Academic Press. Arises from an imbalance in magnetic moments of electrons Type: CoFe, TERFENOL-D, GALFANOL (FeGa) Challenges: TERFENOL-D: eddy current loss, brittle

5. Piezoelectricity Property of materials to convert between mechanical strain and voltage Challenges: Stiffness, anisotropy, leads Design: Geometry, ratio of piezo to magnetostrictive Type: PZT, BaTi Sources: Morgan, TRS

6. Lamination Design question: How to connect magnetostrictive to piezoelectric to maximize transferred strain and minimize chance of failure? Options:  Bulk: Conductive epoxy (Ag)  Composite: cold compression

7. Power Conditioning Design question: How to most effectively normalize and store the electric energy produced by the device? Challenges  Appropriate size capacitor/battery  Rectifying circuit  Appropriate resistance in circuit Sources: EE students

8. Application Sources:  Windows on busy street: 100 Hz at 1μm  The London Millenium Footbridge: 1.1 Hz. Uses:  Small or non-constant powered devices  Existing devices <1 mW  LED ( ~30 mW)  Themocouple; wireless sensor; actuator

9. Next Research Steps Evaluate kinetic energy of various sources  Ducts, motors, ground Calculate energy loss through 2 transformations  mechanical→magnetic→electrical (DC↔AC) Answer materials questions  Will magnetostrictive strain cause failure in piezo?  Ideal frequencies; ratio magnetostrictive/piezo  Bulk vs. Composite

10. Project Schedule