Device with magnetoplastic and/or magnetoelastic thin-film transducer and pick-up coil for harvesting energy

• US 8,008,816 B2
• Filed: 10/19/2007
• Issued: 08/30/2011
• Est. Priority Date: 10/19/2006
• Status: Active Grant

• Current Assignee: Boise State University
• Original Assignee: Boise State University
• Inventors: Hampikian, Greg, Mullner, Peter
• Primary Examiner(s): Tamai; Karl I
• Application Number:
  US11/875,732
• Publication Number:
  US 20080143195A1
• Time in Patent Office: 1,411 Days
• Field of Search: 310/26, 310/339, 310/311
• US Class Current: 310/26
• CPC Class Codes: H10N 35/00 Magnetostrictive devices integrated devices or assemblies of multiple devices H10N39/00

Abstract

A magnetoplastic and/or magnetoelastic material transduces linear motion, delivered to it by a mechanical connection, into a change of magnetic field, via twin boundary deformation. A bias magnetic field assures a net change of magnetization during the deformation, and a coil, coaxial with the magnetoplastic/elastic material, couples the magnetic field change to an electrical output. The bias magnetic field or a device that produces strain in a reverse direction resets the magnetomechanical transducer to its initial state. Microgenerators using the magnetoplastic/elastic material may be connected in series or parallel, combined with solar cells, and used to capture energy from passive motion such as random, cyclic or vibrational motion.

Claims

1. A magnetomechanical device for harvesting energy from random, cyclic or vibrational motion, the device comprising:

a support with a hole extending into the support, the hole having an opening and a longitudinal axis;

a magnet connected to said support and providing a magnetic bias,

a first thin-film transducer on said support and having a portion extending over the hole and coaxial with said hole longitudinal axis, said portion comprising magnetoplastic and/or magnetoelastic material that, upon deformation of the material into said hole by an applied force, produces a net change in magnetization relative to said magnetic bias by twin boundary rearrangement, wherein said portion is coaxial with said longitudinal axis of the hole; and

a one-turn conducting-thin-film pick-up coil on said first thin-film transducer and having a coil opening that is over said portion of the first thin-film transducer, wherein the coil opening is coaxial with the hole and with said portion, and wherein said applied force reaches said portion of the first thin-film transducer through the coil opening, and the conducting-thin-film pick-up coil transduces magnetization to electrical energy;

wherein said first transducer resides in an initial state prior to deformation by said applied force, and wherein the magnet is adapted to reset said material to the initial state after said deformation.

2. A system as in claim 1, wherein the first thin-film transducer comprises material selected from the group consisting of:

Heusler shape-memory alloy, non-Heusler ferromagnetic shape-memory alloy, antiferromagnetic shape-memory alloy, non-shape-memory magnetoplastic alloy, Ni.sub.2MnGa, Dy, .alpha.-Fe, Co—

Ni, .tau.-MnAl—

C, L1.sub.OFePd, L1.sub.0CoPt, L1.sub.OFePt, Ni.sub.2MnGa, Co.sub.2NiGa, Ni.sub.2MnAl, Ni.sub.2FeGa, Fe.sub.3Pd, Fe—

Pd—

PT, .gamma.-Mn—

Fe—

Cu, Ni.sub.51Mn.sub.28Ga.sub.21, Ni—

Mn—

Ga alloys, Ni—

Mn—

Ga ferromagnetic martensite, and combinations thereof.