SBIR-STTR Award

Energy harvesting devices utilizing magnetostrictive materials are a logical choice for harvesting the high impedance (high force, low displacement) vibrations found aboard Navy ships. Force-based devices, enabled by magnetostrictive materials, can harvest energy over an extremely large bandwidth, approximately 35 and 70 Hz currently, making them more desirable in situations aboard Navy ships were transient vibration conditions created by varying ship speeds is present. This broader bandwidth also means easier installation of the devices without the need for exact placement on the vibration source and eliminating tuning requirements typical of the displacement based devices. The robustness and formability that Galfenol alloys exhibit allow 1-dimensional (1D), 2-dimensional (2D), and 3-dimensional (3D) energy harvesting devices to be developed and optimized for the identified need and vibration coupling scheme. A 1D Galfenol device could consist of wire(s) bundled together to form an energy harvesting cable that could be wrapped around a vibrating column; a 2D Galfenol device could consist of a single Galfenol sheet attached to a vibrating panel; and a 3D Galfenol device could consist of structural support on-which the vibration source is mounted. The proposed work will investigate 1D and 2D Galfenol energy harvesting devices in Navy ship environments.

Benefit:
Wireless-networked sensors have long held promise for decreased down-time and reduced life-cycle costs by allowing automated monitoring of essential equipment. A critical obstacle to widespread adoption is the means of powering the network. Batteries are not an optimal solution as they require manual replacement, defeating cost-reduction benefits. Powering the sensors by wire limits sensor location and does not achieve the level of monitoring needed. The development of an energy harvester that can be directly integrated into a wireless sensor is the critical disruptive technology that will open up the multi-billion dollar wireless sensor condition-based monitoring market for both DoD and worldwide commercial applications. The solution created by the proposed work will benefit all branches of the military. While the specific scope addresses a need by the Navy, the other services have similar needs for wireless sensor networks. The Navy benefits by using the energy-harvester powered wireless sensors for use aboard surface ships where a wired network would add unnecessary weight and expensive ship alterations. Assuming a network of 250 sensors per vessel and 275 surface combatants alone, this one application represents a potential market of $35 million and does not include reserve and auxiliary vessels. The commercial applications for the proposed solution are considerable. Every industrial plant that wishes to implement a wireless sensor CBM approach would find the completed solution easy to install and operate as it would not require substantial installation costs. Assuming an average of $10,000 of sensors per plant, the US market alone would be $600-900 Million.

Keywords:
energy harvester, energy harvester, Magnetostrictive, galfenol, power scavenging, Terfenol-D

Development of an energy harvesting system utilizing the magnetostrictive material, Galfenol, will be completed in this effort. The energy harvesting system will consist of Galfenol plates or sheets, magnetic circuit components, coupling structure, power conditioning electronics, sensor, and wireless transmitter. Lab testing and relevant environment testing through sea-trials will be completed on the system and compared to the predicted performance of FEA and analytical models. In addition, Galfenol wire fabrication efforts will be advanced with the primary goal of developing a Galfenol alloy and process capable of producing wire with the appropriate texture to maximize energy harvesting properties for future 1D devices.

Benefit:
Successful completion of the proposed Phase II work will demonstrate the energy harvesting capability of a 2D patch energy harvesting system using Galfenol in a real-world at-sea environment. Wireless-networked sensors have long held promise for decreased down-time and reduced life-cycle costs by allowing automated monitoring of essential equipment. A critical obstacle to widespread adoption is the means of powering the network. The development of an energy harvester that can be directly integrated into a wireless sensor, as will be shown with successful completion of this effort, is the critical disruptive technology that will open up the multi-billion dollar wireless sensor condition-based monitoring market for both DoD and worldwide commercial applications. In addition to the 2D energy harvesting system development, advancements in Galfenol wire fabrication technology will be made in the Phase II work. Development of a Galfenol cable in Phase II will allow future research to begin designing and fabricating 1D energy harvesting structures. These innovative energy harvesters have the potential to be used for suspending vibrating loads, cargo, connecting rafted objects, or coupling to curved or irregular shaped vibrating surfaces. Wire arrangement, magnetic bias, coil placement, and return path are all considerations in the design of an energy harvesting cable.

Keywords:
magnetostriction, wireless sensors, Energy Harvesting, galfenol, Vibrations