Micro-turbines, roller bearings, bushings, and design of hollow closed structures and fabrication methods for creating such structures

• US 8,257,573 B1
• Filed: 09/23/2009
• Issued: 09/04/2012
• Est. Priority Date: 09/24/2003
• Status: Active Grant

• Current Assignee: Microfabrica Incorporated (Technoprobe S.P.A.)
• Original Assignee: Microfabrica Incorporated (Technoprobe S.P.A.)
• Inventors: Cohen, Adam L.
• Primary Examiner(s): Van, Luan
• Application Number:
  US12/565,186
• Time in Patent Office: 1,077 Days
• Field of Search: 205/118, 205/122, 205/170, 205/181, 205/220, 205/223
• US Class Current: 205/118
• CPC Class Codes: B33Y 10/00 Processes of additive manufacturing
• CPC Class Codes: C25D 1/003 3D structures, e.g. superposed patterned layers

Abstract

Multi-layer fabrication methods (e.g. electrochemical fabrication methods) for forming microscale and mesoscale devices or structures (e.g. turbines) provide bushings or roller bearing that allow rotational or linear motion which is constrained by multiple structural elements spaced from one another by gaps that are effectively less than minimum features sizes associated with the individual layers used to form the structures. In some embodiments, features or protrusions formed on different layers on opposing surfaces are offset along the axis of layer stacking so as to bring the features into positions that are closer than allowed by the minimum features sizes associated with individual layers. In other embodiments, interference is used to create effective spacings that are less than the minimum features sizes.

Claims

1. A fabrication process for producing a microscale or mesoscale three-dimensional structure comprising at least one structural material, from a plurality of adhered layers, comprising at least one structural material and at least one sacrificial material, the process comprising:

(A) forming a first layer by depositing at least one structural material and at least one sacrificial material and planarizing the at least one structural material and the at least one sacrificial material to produce a planarized layer having a desired lower boundary level and a desired upper boundary level;

(B) forming a plurality of layers such that each successive layer is formed adjacent to and adhered to a previously formed layer along an axis of layer formation, wherein an initial successive layer is formed adjacent to and adhered to the first layer, and wherein said forming comprises repeating (A) multiple times;

(C) after forming the plurality of layers, separating the at least one sacrificial material from the at least one structural material such that two components of the structure can move relative to one another, wherein each of the two components have at least one surface that opposes a surface of the other component wherein at least one of the opposing surfaces comprises a plurality of protrusions and the other opposing surface comprises at least one protrusion, and wherein opposing protrusions exist on different layers, wherein a lateral separation between neighboring opposing protrusions is less than a minimum feature size for a gap in structural material on a single layer;

(D) displacing the two components along the axis of layer formation such that one of the plurality of protrusions is shifted relative to the at least one protrusion so that at least a portion of the protrusions at least partially align along the axis of layer formation;

(E) after said displacing, translating the two components relative to one another along a path that is perpendicular to the axis of layer formation.

2. A fabrication process for producing a microscale or mesoscale three-dimensional structure comprising at least one structural material, from a plurality of adhered layers, comprising at least one structural material and at least one sacrificial material, the process comprising:

(A) forming a first layer by depositing at least one structural material and at least one sacrificial material and planarizing the at least one structural material and the at least one sacrificial material to produce a planarized layer having a desired lower boundary level and a desired upper boundary level;

(B) forming a plurality of layers such that each successive layer is formed adjacent to and adhered to a previously formed layer along an axis of layer formation, wherein an initial successive layer is formed adjacent to and adhered to the first layer, and wherein said forming comprises repeating (A) multiple times;

(C) after forming the plurality of layers, separating the at least one sacrificial material from the at least one structural material such that two components of the structure can move relative to one another, wherein each of the two components have at least one surface that opposes a surface of the other component wherein at least one of the opposing surfaces comprises a plurality of protrusions and the other opposing surface comprises at least one protrusion, and wherein opposing protrusions exist on different layers, wherein a lateral separation between neighboring opposing protrusions is less than a minimum feature size for a gap in structural material on a single layer;

(D) translating the two components relative to one another along a path that is perpendicular to the axis of layer formation.

3. The process of claim 2 wherein a first protrusion exists on an nth layer and wherein a second opposing protrusion exists on an (n+1)th layer, and a third protrusion which opposes the second protrusion exists on an (n+2)th layer.

4. The process of claim 2 wherein a plurality of first protrusions exist on an nth and an (n+2)th layer and wherein a plurality second opposing protrusions exists on an (n+1)th layer and an (n+3)th layer.

5. A fabrication process for producing a microscale or mesoscale three-dimensional structure comprising at least one structural material, from a plurality of adhered layers, comprising at least one structural material and at least one sacrificial material, the process comprising:

(A) forming a first layer by depositing at least one structural material and at least one sacrificial material and planarizing the at least one structural material and the at least one sacrificial material to produce a planarized layer having a desired lower boundary level and a desired upper boundary level;

(B) forming a plurality of layers such that each successive layer is formed adjacent to and adhered to a previously formed layer along an axis of layer formation, wherein an initial successive layer is formed adjacent to and adhered to the first layer, and wherein said forming comprises repeating (A) multiple times;

(C) after forming the plurality of layers, separating the at least one sacrificial material from the at least one structural material such that two components of the structure can move relative to one another, wherein each of the two components have at least one surface that opposes a surface of the other component wherein at least one of the opposing surfaces comprises a plurality of protrusions and the other opposing surface comprises at least one protrusion, wherein a lateral separation between neighboring opposing protrusions is greater than a minimum feature size for a gap in structural material on a single layer;

(D) displacing the two components laterally such that one of the plurality of protrusions is shifted relative to the at least one protrusion along a lateral direction such that the gap between the opposing protrusions is less than the minimum feature size;

(E) after said displacing, translating the two components relative to one another wherein the motion of translation is constrained by the original lateral displacement so that the gap between the opposing protrusions remains less than the minimum feature size.

7. The fabrication process of claim 5 wherein the three-dimensional structure comprises a turbine having an impeller, a shaft, and a bore, wherein the first component comprises the bore and the second component comprises the shaft and wherein the shaft has a longitudinal axis parallel to the axis of layer formation, and wherein the bore and shaft have an effective radial spacing at a given axial level which is smaller than the minimum feature size.

8. The fabrication process of claim 5 wherein the three-dimensional structure comprises a turbine having an impeller, at least one pair of races and a plurality of rollers, wherein each of the impeller, the races, and the rollers are formed from a plurality of the adhered layers and wherein the races are rotatable with respect to one another along an axis which is parallel to the axis of layer formation and which are separated from one another by the plurality of rollers which are also rotatable relative to the pair of races and wherein an effective spacing between the races and the rollers is less than the minimum feature size at a given axial level.

9. The fabrication process of claim 5 wherein the three-dimensional structure comprises a linear translator having a beam, at least one pair of races and a plurality of rollers wherein each of the beam, the races, and the rollers are formed from a plurality of the adhered layers and wherein each of the races are rotatable with respect to the beam along an axis which is parallel to the axis of layer formation and wherein the beam is separated from each race by the plurality of rollers, wherein the races and rollers are rotatable relative to each other and wherein an effective spacing between the races and the rollers is less than the minimum feature size at a given axial level.

10. The fabrication process of claim 5 wherein the three-dimensional structure comprises at least one pair of races and a plurality of rollers, wherein each of the races and the rollers are formed from a plurality of the adhered layers and wherein the races are rotatable with respect to one another along an axis which is parallel to the axis of layer formation and which are separated from one another by the plurality of rollers which are also rotatable relative to the pair of races and wherein an effective spacing between the races and the rollers is less than the minimum feature size at a given axial level.

11. The fabrication process of claim 5 wherein the three-dimensional structure comprises a bushing having at least one shaft and at least one bore formed from a plurality of adhered layers and wherein the shaft and bore are rotatable with respect to one another along an axis which is parallel to the axis of layer formation where the spacing between the bore and the shaft have an effective radial spacing at a given axial level that is less than the minimum feature size at the given axial level.

6. A fabrication process for producing a microscale or mesoscale three-dimensional structure, comprising at least one structural material, from a plurality of adhered layers, comprising at least one structural material and at least one sacrificial material, the process comprising:

(A) forming a first layer by depositing at least one structural material and at least one sacrificial material and planarizing the at least one structural material and the at least one sacrificial material to produce a planarized layer having a desired lower boundary level and a desired upper boundary level;

(B) forming a plurality of layers such that each successive layer is formed adjacent to and adhered to a previously formed layer along an axis of layer formation, wherein an initial successive layer is formed adjacent to and adhered to the first layer, and wherein said forming comprises repeating (A) multiple times;

(C) after forming the plurality of layers, separating the at least one sacrificial material from the at least one structural material such that two components of the structure can move relative to one another, wherein each of the two components have at least one surface that opposes a surface of the other component wherein at least one of the opposing surfaces comprises a plurality of protrusions and the other opposing surface comprises at least one protrusion, wherein a lateral separation between neighboring opposing protrusions is greater than a minimum feature size for a gap in structural material on a single layer;

(D) displacing the two components laterally such that one of the plurality of protrusions is shifted relative to the at least one protrusion so that they at least partially align along a lateral direction and such that the gap between the displaced protrusions is less than the minimum feature size;

(E) after said displacing rotating the two components relative to one another about an axis parallel to the axis of layer formation.