Complex microdevices and apparatus and methods for fabricating such devices

• US 20030183008A1
• Filed: 12/06/2002
• Published: 10/02/2003
• Est. Priority Date: 12/06/2001
• Status: Active Grant

• Current Assignee: Memgen Corporation (Technoprobe S.P.A.)
• Original Assignee: Memgen Corporation (Technoprobe S.P.A.)
• Inventors: Cohen, Adam L., Lockard, Michael S., Bang, Christopher A., Evans, John D.
• Granted Patent: US 7,185,542 B2
• Time in Patent Office: Days
• US Class Current: 73/514.01
• CPC Class Codes: B33Y 10/00 Processes of additive manufacturing
• CPC Class Codes: B81C 1/0019 Flexible or deformable structures not provided for in groups B81C1/00142 - B81C1/00182

Abstract

Various embodiments of the invention are directed to various microdevices including sensors, actuators, valves, scanning mirrors, accelerometers, switches, and the like. In some embodiments the devices are formed via electrochemical fabrication (EFAB™)

Claims

1. A microdevice comprising at least one of:

a. a sensor comprising at least two sets of capacitor plates wherein each set of plates comprises a plurality of plates;

b. an actuator comprising at least two sets of capacitor plates wherein each set includes a plurality of plates and wherein a motion of the actuator is perpendicular to a plane of the plates;

c. an actuator comprising at least two sets of capacitor plates wherein each set includes a plurality of plates and wherein a motion of the actuator is in a direction parallel to a plane of the plates, and wherein a portion of the plurality of plates in one set are positioned in a first plane while another portion of the plurality of the plates of the one set are positioned in a second plane offset from the first plane;

d. an actuator comprising at least two sets of capacitor plates wherein each set includes a plurality of plates and wherein a motion of the actuator is in a direction parallel to a plane of the plates, and wherein the plurality of plates in one set are positioned in an array that extends in three dimensions;

e. an electrostatic actuator comprising at least one moveable member and at least one actuation electrode for causing movement of the moveable member wherein the electrode and/or the moveable member is configured to have a contour that leads to a spacing between moveable member and the electrode when the moveable member is in its deflected position toward the electrode which is more uniform than when the moveable member is in an undeflected position;

f. an electrostatic actuator comprising at least one moveable member and at least one actuation electrode for causing movement of the moveable member wherein the electrode and/or the moveable member has a configuration that brings portions of the electrode and member closer together without significantly interfering with the movement of the member;

g. an electrostatic actuator comprising at least one moveable member and at least one actuation electrode for causing movement of the moveable member wherein the electrode has at least one sidewall or at least one protrusion in a region that reduces the separation between the electrode and the member without hindering the motion of the member;

h. an electrostatic actuator comprising at least one moveable member and at least two actuation electrodes that can be activated to create forces that pull the moveable member in opposing directions;

i. an electrostatically actuated micro-mirror scanning system comprising contoured electrodes that allow a reduced drive voltage without hindering mirror movement;

j. a structure comprising a multi-level micro flow channel;

or

k. a metal mold have a plurality of levels having features with dimensions on the order of 10s of microns or less.

2. The microdevice of claim 1 formed at least in part via electrochemical fabrication.

3. A process for forming a multilayer microdevice, comprising:

(a) forming a layer of at least one material on a substrate that may include one or more previously deposited layers of one or more materials;

(b) repeating the forming operation of “

(a)”

one or more times to form at least one subsequent layer on at least one previously formed layer to build up a three-dimensional structure from a plurality layers;

wherein the forming of at least one layer, comprises;

(1) supplying a substrate on which one or more successive depositions of one or more materials may have occurred;

(2) supplying a mask having a desired pattern or capable of being activated to effectively deposit or etch a desired pattern of material;

(3) bringing the mask and the substrate into contact or proximity such that electrochemical process pockets are formed having a desired registration with respect to any previous depositions and providing a desired electrolyte solution such that the solution is provided within the electrochemical process pockets; and

(4) applying a desired electrical activation to cause a desired material to be deposited onto the substrate or removed from the substrate in preparation for deposition of a material onto the substrate;

wherein the microdevice includes one or more of the following;

i. an accelerometer,

ii. a switch,

iii. a valve,

iv. a 3-D tilt mirror,

v. a fluid well,

vi. a tool for producing other microstructures or structures with micro-patterning,

vii. an actuator including a contoured electrode,

viii. a bellows controlled valve,

ix. an actuator with pull down and pull up electrodes,

x. a valve comprising a shape memory device,

xi. a bistable valve,

xii. a device at least partly surrounded by a conductive shield wall.

4. The process of claim 3 additionally comprising one or more of the following operations:

a. selectively electrodepositing a first conductive material and electrodepositing a second conductive material, wherein one of the first or second conductive materials is a sacrificial material and the other is a structural material;

b. electrodepositing a first conductive material, selectively etching the first structural material to create at least one void, and electrodepositing a second conductive material to fill the at least one void;

c. electrodepositing at least one conductive material, depositing at least one flowable dielectric material, and depositing a seed layer of conductive material in preparation for formation of a next layer of electrodeposited material, and/or

d. selectively electrodepositing a first conductive material, then electrodepositing a second conductive material, then selectively etching one of the first or second conductive materials, and then electrodepositing a third conductive material, wherein at least one of the first, second, or third conductive materials is a sacrificial material and at least one of the remaining two conductive materials is a structural material.

5. A microdevice, comprising:

a plurality of layers of successively deposited material, wherein the deposition of each layer of material comprises,

a. deposition of at least a first material; and

b. deposition of at least a second material; and

wherein at least a portion of the first or second material is removed after deposition of the plurality of layers; and

wherein a structure resulting from the deposition and the removal provides at least one structure that can function as (1) an accelerometer, (2) a toroidal inductor, (3) a switch, (4) a valve, (5) a helical inductor, (6) a 3-D tilt mirror, (7) a fluid well, (8) an antenna, or (9) a mold.

6. The microdevice of claim 5 wherein the microdevice comprises an accelerometer comprising:

a proof mass; and

a plurality of spring-like structures for supporting the proof mass relative to a substrate;

where a portion of the plurality of spring-like structures attach to the proof mass below a center of mass of the proof mass and a plurality of the spring-like structures attach to the proof mass above the center of mass of the proof mass.

7. The microdevice of claim 5 wherein the microdevice comprises an accelerometer comprising:

a proof mass; and

a plurality of spring-like structures for supporting the proof mass relative to a substrate;

where a portion of the plurality of spring-like structures attach to the proof mass in a common plane that includes the center of mass of mass of the proof mass.

8. The microdevice of either of claims 6 wherein proof mass acts as a first capacitor plate, additionally comprising:

a conductive element that functions as a second capacitor plate separated from the proof mass and supported relative to a substrate, wherein the second capacitor plate is suspended above the substrate.

9. The microdevice of claim 8 wherein a parasitic capacitance of a circuit comprising the first and second capacitance plate and the substrate is reduced from what the parasitic capacitance would have been if the second capacitance plate were formed on the substrate.

10. The microdevice of claim 6 wherein at least one motion limiting structure is located between the proof mass and the second capacitance plate so as to inhibit the proof mass and second capacitance plate from contacting one another, wherein the at least one limiting structure is either a dielectric or a structure that is electrically isolated from at least one of the proof mass or the second capacitance plate.

11. The microdevice of claim 10 wherein the limiting structure is a plurality of structures each with a cross-sectional dimension substantially smaller than that of either the second capacitance plate or the proof mass.

12. The microdevice of claim 10 wherein the motion limiting structure inhibits the proof mass and second capacitance plate from shorting together during maximum deflection of the proof mass relative to and toward the second capacitance plate.

13. The microdevice of claims 6 wherein the proof mass has a thickness greater than the thickness of at least one of the plurality of the spring-like structures.

14. The microdevice of claims 13 wherein the proof mass has a thickness greater than the thickness of each of the plurality of the spring-like structures.

15. The microdevice of claim 5 wherein the microdevice comprises a plurality of microdevices selected from the group of structures.

16. The microdevice of claim 6 wherein the microdevice comprises a structure of overall dimension less than 1 centimeter with at least some design features having dimensions smaller than 500 microns, more preferably smaller than 100 microns, or most preferably smaller than 25 microns.

17. The microdevice of claim 5 wherein the microdevice comprises a valve that has a valve seal and a valve seat wherein at least one of the valve seat or valve seal is supported by at least one corrugated support structure.

18. The microdevice of claim 17 wherein the valve is a check valve.

19. The microdevice of claim 17 wherein the corrugated support structure comprises at least two spring-like structures.

20. The microdevice of claim 5 wherein the microdevice comprises a 3-D tilt mirror wherein the mirror comprises a rotatable structure with a reflective surface that is supported by at least one spring-like structure, wherein the spring-like structure is formed from the same material as that which forms the reflective surface.

21. The microdevice of claim 18 where the mirror can rotate around a first axis and about a second axis that is substantially perpendicular to the first axis, wherein the first axis is defined by first and second rod-like elements which produce a return force when twisted, wherein the first and second rod-like elements are supported by a loop shaped structure, which loop shaped structure is in turn supported by third and fourth rod-like elements which produce a return force when twisted, wherein the first and second rod-like elements are substantially co-linear along a first line and the third and fourth rod-like elements are substantially co-linear along a second line where-in the first and second lines are substantially perpendicular to one another.

22. The microdevice of claim 18 wherein the rotatable structure with the reflective surface has thickness dimension that is at least in part substantially thicker than the thickness dimension of the first and second rod-like elements, wherein portions of the rotatable structure may be thinner than a maximum thickness of the rotatable structure such that the moment of inertia of the rotatable structure is reduced.

23. The microdevice of claim 21 wherein the loop shaped structure has a thickness dimension that is substantially thicker than the thickness dimension of the third and forth rod-like elements.

24. The microdevice of claim 21 wherein the loop shaped structure has thickness dimension that is substantially thicker than the thickness dimension of the first and second rod-like elements.

25. The microdevice of claim 22 wherein the mirror is caused to rotate by activation of one or more of a plurality of electrodes located between the mirror and a substrate, wherein at least a plurality of the electrodes are separated from the substrate.

26. The microdevice of claim 25 wherein a parasitic capacitance of a circuit comprising the electrodes and the substrate is reduced from what the parasitic capacitance would have been if the electrodes were formed on the substrate.

27. The microdevice of claim 5 wherein the microdevice comprises a structure having a multilevel flow channel.

28. The microdevice of claim 5 wherein the microdevice comprises a multilevel mold.

29. A method of manufacturing a microdevice, comprising:

depositing a plurality of adhered layers of material, wherein the deposition of each layer of material comprises,

a. selective deposition of at least a first material;

b. deposition of at least a second material; and

c. planarization of at least a portion of the deposited material;

removing of at least a portion of the first or second material after deposition of the plurality of layers;

wherein a structure resulting from the deposition and the removal provides at least one structure that can function as (1) an accelerometer, (2) a toroidal inductor, (3) a switch, (4) a valve, (5) a helical inductor, (6) a 3-D tilt mirror, (7) a fluid well, (8) an antenna, or (9) a mold.

30. A microaccelerometer, comprising:

a proof mass; and

at least one of

a plurality of spring-like structures for supporting the proof mass relative to a substrate;

where a portion of the plurality of spring-like structures attach to the proof mass below a center of mass of the proof mass and a plurality of the spring-like structures attach to the proof mass above the center of mass of the proof mass;

or

a plurality of spring-like structures for supporting the proof mass relative to a substrate;

where a portion of the plurality of spring-like structures attach to the proof mass in a common plane that includes the center of mass of mass of the proof mass.

31. The microaccelerometer of claim 30 wherein proof mass acts as a first capacitor plate, additionally comprising:

a conductive element that functions as a second capacitor plate separated from the proof mass and supported relative to a substrate wherein the second capacitor plate is suspended above the substrate.

32. The microaccelerometer of claim 31 wherein a parasitic capacitance of a circuit comprising the first and second capacitance plate and the substrate is reduced from what the parasitic capacitance would have been if the second capacitance plate were formed on the substrate.

33. The microaccelerometer of claim 30 wherein at least one motion limiting structure is located between the proof mass and the second capacitance plate so as to inhibit the proof mass and second capacitance plate from contacting one another, wherein the at least one limiting structure is either dielectrical or is electrically isolated from at least one of the proof mass or the second capacitance plate.

34. The microaccelerometer of claim 33 wherein the limiting structure is a plurality of structures each with a cross-sectional dimension substantially smaller than that of either the second capacitance plate or the proof mass.

35. The microaccelerometer of claims 33 wherein the motion limiting structure inhibits the proof mass and second capacitance plate from shorting together during maximum deflection of the proof mass relative to and toward the second capacitance plate.

36. The microaccelerometer of claim 30 wherein the proof mass has a thickness greater than the thickness of at least one of the plurality of the spring-like structures.

37. The microaccelerometer of claim 36 wherein the proof mass has a thickness greater than the thickness of each of the plurality of the spring-like structures.

38. A microvalve that has a valve seal and a valve seat wherein at least one of the valve seat or valve seal is supported by at least one corrugated support structure.

39. The microvalve of claim 38 wherein the valve is a check valve.

40. The microvalve of claim 39 wherein the corrugated support structure comprises at least two spring-like structures.

41. A 3-D tilt mirror having features with dimensions on the order of 10s of microns comprising a rotatable mirror structure with a reflective surface that is supported by at least one spring-like structure, wherein the spring-like structure is formed from the same material as that which forms the reflective surface.

42. The mirror of claim 41 wherein the mirror can rotate around a first axis and about a second axis that is substantially perpendicular to the first axis, wherein the first axis is defined by first and second rod-like elements which produce a return force when twisted, wherein the first and second rod-like elements are supported by a loop shaped structure, which loop shaped structure is in turn supported by third and fourth rod-like elements which produce a return force when twisted, wherein the first and second rod-like elements are substantially co-linear a long a first line and the third and fourth rod-like elements are substantially co-linear along a second line where-in the first and second lines are substantially perpendicular to one another.

43. The mirror of either of claim 42 wherein the rotatable structure with the reflective surface has thickness dimension that is thicker than the thickness dimension of the first and second rod-like elements.

44. The mirror of either of claims 42 wherein the loop shaped structure has a thickness dimension that is thicker than the thickness dimension of the third and forth rod-like elements.

45. The mirror of either of claim 42 wherein the loop shaped structure has thickness dimension that is thicker than the thickness dimension of the first and second rod-like elements.

46. The mirror of claim 42 wherein the mirror is caused to rotate by activation of one or more of a plurality of electrodes located between the mirror and a substrate, wherein at least a plurality of the electrodes are separated from the substrate.

47. The mirror of claim 46 wherein a parasitic capacitance of a circuit comprising the electrodes and the substrate is reduced from what the parasitic capacitance would have been if the electrodes were formed on the substrate.