Actively switchable nano-structured adhesive

• US 20080014465A1
• Filed: 11/10/2005
• Published: 01/17/2008
• Est. Priority Date: 11/10/2004
• Status: Active Grant

• Current Assignee: Regents of the University of California (University of California)
• Original Assignee: Regents of the University of California (University of California)
• Inventors: Fearing, Ronald, Groff, Richard, Majidi, Carmel, Bachrach, Abraham
• Granted Patent: US 7,914,912 B2
• Time in Patent Office: Days
• US Class Current: 428/692.1
• CPC Class Codes: B81B 3/0032 Structures for transforming energy not provided for in groups B81B3/0021 - B81B3/0029
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: Y10T 428/24355 Continuous and nonuniform or irregular surface on layer or component [e.g., roofing, etc.]
• CPC Class Codes: Y10T 428/32 Composite [nonstructural laminate] of inorganic material having metal-compound-containing layer and having defined magnetic layer

Abstract

Described herein is a microstructure having a substrate and a plurality of nano-fibers attached to the substrate. Each nano-fiber moves between the first and second states without an external mechanical load being applied to the nano-fibers. Each nano-fiber is configured to move between a first state and a second state in response to applied electricity, magnetism, chemical solution, heat, or light. Each nano-fiber is straight in the first state and curved in the second state, and when the nano-fibers are in the second state and in contact with a contact surface, the nano-fibers adhere to the contact surface.

Claims

1. A fabricated microstructure, comprising:

a substrate; and

a plurality of nano-fibers attached to the substrate, each nano-fiber configured to move between a first state and a second state in response to applied electricity, magnetism, chemical solution, heat, or light,

wherein each nano-fiber is straight in the first state and curved in the second state, and

wherein, when the nano-fibers are in the second state and in contact with a contact surface, the nano-fibers adhere to the contact surface.

2. The fabricated microstructure of claim 1, wherein each nano-fiber is differentially coated with an electroactive polymer.

3. The fabricated microstructure of claim 2, further comprising:

a set of electrodes disposed on the substrate, wherein in response to an applied voltage, the electrodes generate an electric field that activates the electroactive polymer on each nano-fiber to bend each nano-fiber.

4. The fabricated microstructure of claim 1, wherein each nano-fiber is differentially coated with magnetostrictive material, and wherein in response to an applied magnetic field, the magnetostrictive material on each nano-fiber bends each nano-fiber.

5. The fabricated microstructure of claim 1, wherein each nano-fiber includes a paramagnetic or ferromagnetic material.

6. The fabricated microstructure of claim 5, further comprising:

a wire disposed on the substrate, wherein in response to an applied current, the wire generates a magnetic field that activates the ferromagnetic material to bend each nano-fiber.

7. The fabricated microstructure of claim 5, wherein each nano-fiber is differentially coated with the paramagnetic or ferromagnetic material.

8. The fabricated microstructure of claim 5, wherein each nano-fiber is formed from paramagnetic or ferromagnetic material.

9. The fabricated microstructure of claim 1, wherein each nano-fiber moves from the first state to the second state in response to applied electricity, magnetism, chemical solution, heat, or light, and wherein each nano-fiber remains in or returns to the first state when electricity, magnetism, chemical solution, heat, or light is not applied.

10. The fabricated microstructure of claim 1, wherein each nano-fiber moves from the second state to the first state in response to applied electricity, magnetism, chemical solution, heat, or light, wherein each nano-fiber remains in or returns to the second state when electricity, magnetism, chemical solution, heat, or light is not applied.

11. The fabricated microstructure of claim 1, wherein each nano-fiber moves between the first and second states without an external mechanical load being applied to the nano-fibers.

12. The fabricated microstructure of claim 1, wherein the entire length of each nano-fiber is curved.

13. A fabricated microstructure, comprising:

a substrate; and

a nano-fiber attached to the substrate,

the nano-fiber configured to move between a first state and a second state in response to an applied electric or magnetic field, wherein the nano-fiber is straight in the first state and curved in the second state, and wherein, when the nano-fiber is in the second state and in contact with a contact surface, the nano-fiber adheres to the contact surface.

14. The fabricated microstructure of claim 13, wherein the nano-fiber is differentially coated with an electroactive polymer, and further comprising:

a set of electrodes disposed on the substrate, wherein in response to an applied voltage, the electrodes generate an electric field that activates the electroactive polymer on the nano-fiber to bend the nano-fiber.

15. The fabricated microstructure of claim 13, wherein the nano-fiber is differentially coated with magnetostrictive material, wherein in response to an applied magnetic field, the magnetostrictive material on the nano-fiber bends the nano-fiber.

16. The fabricated microstructure of claim 13, wherein the nano-fiber includes a paramagnetic or ferromagnetic material, and further comprising:

a wire disposed on the substrate, wherein in response to an applied current, the wire generates a magnetic field that activates the paramagnetic or ferromagnetic material to bend the nano-fiber.

17. A method of forming a fabricated microstructure, comprising:

forming a substrate; and

forming a plurality of nano-fibers attached to the substrate,

each nano-fiber configured to move between a first state and a second state in response to applied electricity, magnetism, chemical solution, heat, or light,

wherein each nano-fiber is straight in the first state and curved in the second state, and

wherein, when the nano-fibers are in the second state and in contact with a contact surface, the nano-fibers adhere to the contact surface.

18. A method of adhering a fabricated microstructure to a contact surface, comprising:

obtaining a substrate having a plurality of nano-fibers attached to the substrate, each nano-fiber configured to move between a first state and a second state in response to applied electricity, magnetism, chemical solution, heat, or light, wherein each nano-fiber is straight in the first state and curved in the second state; and

placing the substrate having the plurality of nano-fibers on the contact surface, wherein, when in the second state, the nano-fibers adhere to the contact surface.

19. The method of claim 18, further comprising:

before placing the substrate on the contact surface, moving the nano-fibers from the first state to the second state by applying electricity, magnetism, chemical solution, heat, or light to the nano-fibers.

20. The method of claim 18, further comprising:

before placing the substrate on the contact surface, moving the nano-fibers from the second state to the first state by applying electricity, magnetism, chemical solution, heat, or light to the nano-fibers.

21. A method of adhering a fabricated microstructure to a contact surface, comprising:

obtaining a substrate having a plurality of nano-fibers attached to the substrate, each nano-fiber configured to move between a first state and a second state in response to applied electricity, magnetism, chemical solution, heat, or light, wherein each nano-fiber is straight in the first state and curved in the second state;

placing the substrate having the plurality of nano-fibers on the contact surface; and

moving the nano-fibers from the first state to the second state by applying electricity, magnetism, chemical solution, heat, or light to the nano-fibers, wherein, when in the second state, the nano-fibers adhere to the contact surface.