Magnetic actuation method

• US 8,779,637 B2
• Filed: 10/23/2009
• Issued: 07/15/2014
• Est. Priority Date: 10/24/2008
• Status: Expired due to Fees

• Current Assignee: Centre National De La Recherche Scientifique, Institut Polytechnique De Grenoble
• Original Assignee: Centre National De La Recherche Scientifique, Institut Polytechnique De Grenoble
• Inventors: O'Brien, Daniel, Delamare, Jrme, Cugat, Orphe, Geoffroy, Olivier
• Primary Examiner(s): Kim, John K
• Application Number:
  US13/125,589
• Publication Number:
  US 20110248581A1
• Time in Patent Office: 1,726 Days
• US Class Current: 310/26
• CPC Class Codes: H01F 10/13 Amorphous metallic alloys, e.g. glassy metals H01F10/3204 takes precedence
• CPC Class Codes: H02K 37/00 Motors with rotor rotating step by step and without interrupter or commutator driven by the rotor, e.g. stepping motors
• CPC Class Codes: H02K 37/10 of permanent magnet type H02K37/02 takes precedence
• CPC Class Codes: H02N 11/006 Motors
• CPC Class Codes: H10N 30/00 Piezoelectric or electrostrictive devices integrated devices or assemblies of multiple devices H10N39/00
• CPC Class Codes: H10N 30/20 with electrical input and mechanical output, e.g. functioning as actuators or vibrators
• CPC Class Codes: H10N 35/00 Magnetostrictive devices integrated devices or assemblies of multiple devices H10N39/00
• CPC Class Codes: H10N 35/80 Constructional details

Abstract

The present invention relates to a magnetic actuation method according to which a magnetized mobile (4) is directed by means of at least one magnetic element (2, 2a, 2b) placed opposite said magnetized mobile, characterized in that the preferred direction (or easy axis) of magnetization is made to turn at every point of said element by applying at least one mechanical constraint to said magnetic element(s) (2, 2, 2b), causing anisotropy within said element and thus moving the magnetized mobile in a preferred linear direction or causing the same to rotate.

Claims

1. A magnetic actuation method, according to which a magnetized mobile (4) is steered by means of at least one magnetic element (2, 2a, 2b) set facing said magnetized mobile, wherein the preferred direction (or easy axis) of magnetization is spun throughout said element round by the application of at least one mechanical stress to said magnetic element(s) (2, 2a, 2b), causing an anisotropy within said element and thus driving the magnetized mobile in a preferred rotation or linear direction, wherein the mechanical stress applied is a unidirectional stress resulting from the bidirectional combination of two unidirectional stress preferably applied along two intersecting directions substantially 45°

apart.

2. A method according to claim 1, wherein the magnetic element (2, 2a, 2b) consists of a magnetic material chosen among soft magnetostrictive materials, the easy magnetization axis whereof can turn under a mechanical stress.

3. A method according to claim 1, wherein the mechanical stress applied is an oriented, directional or anisotropic stress.

4. A method according to claim 1, wherein the magnetized mobile is held in at least one stable position in the absence of a mechanical stress applied to at least one magnetic element, the stable position(s) being determined by at least one shape anisotropy of said at least one magnetic element.

5. A method according to claim 4, wherein the magnetized mobile is held in several stable positions, regularly spaced from one another, in the absence of a mechanical stress, said stable positions being determined by an identical periodic anisotropy of said at least one magnetic element.

6. A method according to claim 1, wherein the magnetic element consists of at least one thin layer (Cm) or at least one element made of a soft magnetostrictive material, such as the following alloy bases:

FeNi, FeCo, FeAl, FeB, FeSiB, FeCoZrNbB, FeCoSmB, FeCoTbB, obtained in amorphous or crystalline form.

7. A method according to claim 6, wherein the magnetic element is deposited on a substrate (3, 3a, 3b), preferably piezoelectric, connected to a direct or alternating voltage generator (5).

8. A method according to claim 7, wherein the substrate is a piezoelectric element (3) of the multi-fiber composite type.