Surface Deformation Actuation Structure

• US 20070263302A1
• Filed: 11/21/2003
• Published: 11/15/2007
• Est. Priority Date: 11/21/2003
• Status: Active Grant

• Current Assignee: Nederlandse Organisatie Voor Toegepast-Natuurwetenschappelijk Onderzoek Tno
• Original Assignee: Nederlandse Organisatie Voor Toegepast-Natuurwetenschappelijk Onderzoek Tno
• Inventors: Rosielle, Petrus Carolus Johannes Nicolaas, Kappelhof, Jakobus, Hamelinck, Roger Franciscus
• Granted Patent: US 8,162,494 B2
• Time in Patent Office: Days
• US Class Current: 359/849
• CPC Class Codes: G02B 26/06 for controlling the phase of light G02B26/08 takes precedence , measuring optical phase difference G01J9/00
• CPC Class Codes: G02B 26/0825 the reflecting element being a flexible sheet or membrane, e.g. for varying the focus flexible mirrors for cosmetic use A45D42/24
• CPC Class Codes: Y10S 359/903 with magnet
• CPC Class Codes: Y10S 359/904 Micromirror

Abstract

A structure such as an electronically deformable mirror contains a deformable membrane, an array of actuators located facing the membrane, each actuator being arranged to actuate local displacement of the membrane perpendicular to its surface. The actuators and the membrane are connected via an array of actuating connections. The actuating connections substantially transmit movement perpendicular to the second surface, but leave planar displacement and/or local rotation of the second surface substantially free. Preferably, the actuators contain an array of soft magnetic islands on a soft magnetic base plane, with actuator coils running around the islands and a system of sort magnetic walls on the base plane to separate the coils. The walls support a soft magnetic resilient surface that extend over of the islands and serve to drive the actuating connections. Preferably the base plane is supported on an array of rod shaped connection elements, leaving space to permit air to circulate between the support structures and the support plate.

Claims

1. A surface deformation actuation structure, comprising:

a deformable membrane that has a first surface and a second surface opposite said first surface;

an array of actuators located facing the second surface, each actuator having an actuating surface, each actuator being arranged to actuate displacement of the actuating surface substantially perpendicularly to the second surface; and

an array of actuating connections, each coupled to the actuating surface of a respective one of the actuators in the array and a respective point of the second surface substantially opposite the actuating surface, each actuating connection having anisotropic stiffness, substantially transmitting movement perpendicular to the second surface and leaving planar displacement and/or local rotation of the second surface substantially free, wherein the array of actuators comprises;

a variably magnetizable base plane,

an array of variably magnetizable islands on said base plane,

actuator coils, each running around a respective one of the islands,

a system of variably magnetizable walls on the base plane, the walls dividing a surface of the base plane into separate cells, each containing a respective one of the islands and coils, and

a variably magnetizable resilient surface, with surface parts that each rest on at least one of the walls of respective cells, extend over a respective one of the islands and contain a respective one of the actuating surfaces.

2. A surface deformation actuation structure according to claim 1, comprising permanent magnets placed on top of the islands.

3. A surface deformation actuation structure according to claim 1, wherein the array of actuators comprises a support plate and the surface deformation actuation structure comprises:

a support structure, and

an array of rod shaped connection elements connecting the support structure and support plate, the array of rod shaped connection elements forming a space to permit air to circulate between the support structure and the support plate, each connection element having anisotropic stiffness, thereby substantially limiting a maximum distance between the support plate and the support structure to a predetermined value, while permitting transverse relative movement between the support structure and the support plate.

4. A surface deformation actuation structure according to claim 3, wherein the support structure comprises a honeycomb structure with cells that extend perpendicular to the support plate, and wall segments surrounding the cells at least in planes perpendicular to the support plate, the connection elements connecting junctions of wall segments to the support plate.

5. A surface deformation actuation structure according to claim 4, comprising thermal isolation material between the wall segments and inner spaces of the cells, the cells being open to permit air circulation from and/or to the support plate through the cells.

6. A surface deformation actuation structure according to claim 1, wherein the first surface is an optical mirror surface.

7. A surface deformation actuation structure according to claim 1, wherein each actuation connection is rod shaped and at least ten times longer perpendicular to the second surface than wide.

8. A surface deformation actuation structure, according to claim 1, further comprising

a variably magnetizable base plate;

an array of variably magnetizable islands on said base plate;

actuator coils, each running around a respective one of the islands;

a system of variably magnetizable wails on the base plate, the walls dividing a surface of the base plate into separate cells, each containing a respective one of the islands and coils; and

a variably magnetizable resilient surface, with surface parts that each rest on at least one of the walls of respective cells, extend over a respective one of the islands and contain a respective one of the actuating surfaces.

9. An actuator array according to claim 8 comprising permanent magnets placed on top of the islands.

10. A support construction, comprising

a support plate;

a support structure; and

an array of rod shaped connection elements connecting the support structure and support plate, the array of rod shaped connection elements forming a space to permit air to circulate between the support structure and the support plate, each connection element having anisotropic stiffness, thereby substantially limiting a maximum distance between the support plate and the support structure to a predetermined value, while permitting transverse relative movement between the support structure and the support plate.

11. A support construction according to claim 10, wherein the support structure comprises a honeycomb structure with cells that extend perpendicular to the support plate, and wall segments surrounding the cells at least in planes perpendicular to the support plate, the connection elements connecting junctions of wall segments to the support plate.

12. A support construction according to claim 10, comprising thermal isolation material between the wall segments and inner spaces of the cells, the cells being open to permit air circulation from and/or to the support plate through the cells.