Electrically driven magnetic shape memory apparatus and method

Patent metadata

Field	Value
Publication number	US-10535457-B2
Application number	US-201615086610-A
Country	US
Kind code	B2
Filing date	Mar 31, 2016
Priority date	Sep 23, 2014
Publication date	Jan 14, 2020
Grant date	Jan 14, 2020

Abstract

An actuation apparatus may include a magnetic shape memory (MSM) element configured to compress locally at a portion of the MSM element in response to a perpendicular concentrated portion of a magnetic field. The apparatus may further include a plurality of conductive coils laterally offset from the MSM element. Central axes of each conductive coil of the plurality of conductive coils may be substantially parallel to a longitudinal axis of the MSM element. The apparatus may also include at least one permanent magnet in proximity to the MSM element. The permanent magnet may generate a significant portion of the magnetic field. By successively applying, reversing, and reducing or eliminating electrical currents applied to the conductive coils, a position of the perpendicular concentrated portion of the magnetic field may be moved relative to the MSM element.

First claim

What is claimed is:

1. A micropump apparatus comprising:
a surface having a first opening and a second opening defined therein;
a magnetic shape memory (MSM) element positioned flush with the surface and adjacent to the first opening and the second opening, the MSM element configured to contract locally at a portion of the MSM element in response to local exposure, at the portion of the MSM element, to a perpendicular concentrated portion of a magnetic field; and
a plurality of conductive coils having a common central axis that is laterally offset from the MSM element, wherein the common central axis is substantially parallel to a longitudinal axis of the MSM element, and wherein the plurality of conductive coils is spaced along the MSM element from the first opening of the surface to the second opening of the surface.

2. The apparatus of claim 1 , further comprising:
at least one permanent magnet in proximity to the MSM element.

3. The apparatus of claim 2 , further comprising:
a ferromagnetic yoke positioned through each of the conductive coils and forming a conductive loop with the MSM element and the at least one permanent magnet.

4. The apparatus of claim 3 , wherein the at least one permanent magnet is coupled to the magnetic yoke within the conductive loop.

5. The apparatus of claim 2 , further comprising:
a second permanent magnet in proximity to the MSM element.

6. The apparatus of claim 5 , wherein the at least one permanent magnet and the second permanent magnet are configured to have an opposing magnetizing direction.

7. The apparatus of claim 2 , wherein the at least one permanent magnet is aligned with the longitudinal axis of the MSM element.

8. The apparatus of claim 2 , wherein the at least one permanent magnet includes an Al—Ni—Co alloy.

9. The apparatus of claim 1 , further comprising a controller coupled to the plurality of conductive coils, wherein the controller is configured to:
apply electrical currents to a first set of the plurality of coils to induce a magnetic field in a first direction;
apply electrical currents to a second set of the plurality of coils to induce a magnetic field in a second direction opposite the first direction; and
reverse a direction of at least one of the electrical currents.

10. The apparatus of claim 1 , wherein the surface is a surface of a plate, the first opening and second opening passing through the plate.

11. The apparatus of claim 10 , wherein the MSM element is in contact with the plate, blocking a path from the first opening to the second opening.

Assignees

• Univ Boise State

Inventors

• Mullner Peter
• Armstrong Andrew
• Finn Kevin
• Rafla Nader

Classifications

• H02N11/00

  Generators or motors not provided for elsewhere; Alleged perpetua mobilia obtained by electric or magnetic means (by hydrostatic pressure F03B17/04; {by mechanical means F03G7/10;} by dynamo-electric means, {including arrangements of permanent magnets interacting with other permanent magnets,} H02K53/00) · CPC title

• F04B43/12

  having peristaltic action · CPC title

• F04B19/006

  Micropumps (F04B43/043 and F04B43/095 take precedence) · CPC title

• H01F1/0308

  with magnetic shape memory [MSM], i.e. with lattice transformations driven by a magnetic field, e.g. Heusler alloys · CPC title

• H01F7/064 Primary

  Circuit arrangements for actuating electromagnets (circuit arrangements for obtaining special operating characteristics H01F7/18; driving circuits for electromagnets making use of a switching regulator H01H47/325) · CPC title