SYMMETRIC, SPATULAR ATTACHMENTS FOR ENHANCED ADHESION OF MICRO-AND NANO-FIBERS

• US 20080070002A1
• Filed: 08/22/2007
• Published: 03/20/2008
• Est. Priority Date: 08/23/2006
• 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: Groff, Richard, Majidi, Carmel, Fearing, Ronald
• Granted Patent: US 8,309,201 B2
• Time in Patent Office: Days
• US Class Current: 428/141
• CPC Class Codes: A44B 18/0015 Male or hook elements A44B18/0007 takes precedence
• CPC Class Codes: C09J 2301/31 the adhesive effect being based on a Gecko structure
• CPC Class Codes: C09J 9/00 Adhesives characterised by their physical nature or the effects produced, e.g. glue sticks C09J7/00 takes precedence
• CPC Class Codes: Y10T 428/24355 Continuous and nonuniform or irregular surface on layer or component [e.g., roofing, etc.]

Abstract

A fabricated nano-structure includes a substrate, a supporting stalk, a node, and at least two spatular plate portions. The supporting stalk has a first end opposite a second end. The first end of the supporting stalk is connected to the substrate. The supporting stalk has a diameter range of about 50 nanometers to about 2 microns. A node is disposed at the second end of the supporting stalk. At least two spatular plate portions are connected to the node. The at least two spatular plate portions have planar geometries and are radially distributed about the node. The at least two spatular plate portions has a ratio of a maximum plate thickness to a maximum plate length of at most about 1:20. The maximum plate length is measured along a line from a boundary of the spatular plate portion to a centroid of the node. The maximum plate length is at least about 100 nanometers. The at least two spatular plate portion adhere to a contact surface using intermolecular forces when the spatular plate portions are in contact with the contact surface.

Claims

1. A fabricated nano-fiber structure, comprising:

a substrate;

a supporting stalk having a first end and a second end, wherein the second end is opposite the first end, wherein the first end is connected to the substrate, and wherein the supporting stalk has a diameter of about 50 nanometers to about 2 microns;

a node that is disposed at the second end of the supporting stalk; and

at least two spatular plate portions connected to the node,

wherein the at least two spatular plate portions have planar geometries,

wherein the at least two spatular plate portions are radially distributed about the node,

wherein each of the at least two spatular plate portions has a ratio of a maximum plate thickness to a maximum plate length of at most about 1;

20, wherein the maximum plate length is measured along a line from a boundary of the spatular plate portion to a centroid of the node, and wherein the maximum plate length is at least about 100 nanometers, and

wherein the at least two spatular plate portions adhere to a contact surface using intermolecular forces when the spatular plate portions are in contact with the contact surface.

2. The fabricated nano-fiber structure of claim 1,

for each of the at least two spatular plate portions:

the maximum plate thickness is the thickness of the thickest portion of the spatular plate portion, and

the maximum plate length is the maximum distance from a point on the boundary of the spatular plate portion to a boundary of the node measured on the line in a transverse plane that contains the node and spatular plate portion,

wherein the transverse plane contains the greatest cross-sectional area of any transverse plane containing the node and the spatular plate portion,

wherein the cross-sectional area of the node in the transverse plane includes the centroid of the node, and

wherein the line is the longest line that connects two points on the boundaries of the at least two spatular plate portions through the centroid.

3. The fabricated nano-fiber structure of claim 1, wherein the maximum plate thickness of each of the at least two spatular plate portion is about 50-100 nanometers.

4. The fabricated nano-fiber structure of claim 1, wherein the maximum plate thickness of each of the at least two spatular plate portion is about 5-50 nanometers.

5. The fabricated nano-fiber structure of claim 1, wherein the at least two spatular plate portions have rectangular shapes.

6. The fabricated nano-fiber structure of claim 1, wherein the at least two spatular plate portions have circular shapes.

7. The fabricated nano-fiber structure of claim 1, wherein the at least two spatular plate portions are symmetrical with respect to the supporting stalk.

8. The fabricated nano-fiber structure of claim 1, wherein the maximum spatular plate length is about 100-500 nanometers.

9. The fabricated nano-fiber structure of claim 1, wherein the contact surface has spacing between surface asperities of at most about 20 times the maximum plate thickness.

10. The fabricated nano-fiber structure of claim 1, wherein the spatular plate portions are formed as a unitary structure.

11. The fabricated nano-fiber structure of claim 10, wherein the unitary structure has a circular shape.

12. The fabricated nano-fiber structure of claim 10, wherein the unitary structure has an irregular shape.

13. A method of forming a fabricated nano-fiber structure, comprising:

obtaining a substrate;

forming a supporting stalk on the substrate, wherein the supporting stalk has a first end and a second end, wherein the second end is opposite the first end, and wherein the first end is connected to the substrate, and wherein the supporting stalk has a diameter of about 50 nanometers to about 2 microns;

forming a node disposed at the second end of the supporting stalk; and

forming at least two spatular plate portions connected to the node,

wherein the at least two spatular plate portions have planar geometries,

wherein the at least two spatular plate portions are radially distributed about the node, and

wherein each of the at least two spatular plate portions has a ratio of a maximum plate thickness to a maximum plate length of at most about 1;

20, wherein the maximum plate length is measured along a line from a boundary of the spatular plate portion to a centroid of the node, and wherein the maximum plate length is at least about 100 nanometers.

14. The method of claim 13,

wherein for each of the at least two spatular plate portions:

the maximum plate thickness is the thickness of the thickest portion of the spatular plate portion, and

the maximum plate length is the maximum distance from a point on the boundary of the spatular plate portion to a boundary of the node measured on the line in a transverse plane that contains the node and spatular plate portion,

wherein the transverse plane contains the greatest cross-sectional area of any transverse plane containing the node and the spatular plate portion,

wherein the cross-sectional area of the node in the transverse plane includes the centroid of the node, and

wherein the line is the longest line that connects two points on the boundaries of the at least two spatular plate portions through the centroid.

15. A method of permanently adhering a fabricated nano-fiber structure to a contact surface, comprising:

obtaining a substrate having;

a supporting stalk having a first end and a second end, wherein the second end is opposite the first end, wherein the first end is connected to the substrate, and wherein the supporting stalk has a diameter of about 50 nanometers to about 2 microns;

a node that is disposed at the second end of the supporting stalk; and

at least two spatular plate portions connected to the node,

wherein the at least two spatular plate portions have planar geometries,

wherein the at least two spatular plate portions are radially distributed about the node, and

wherein each of the at least two spatular plate portions has a ratio of a maximum plate thickness to a maximum plate length of at most about 1;

20, wherein the maximum plate length is measured along a line from a boundary of the spatular plate portion to a centroid of the node, and wherein the maximum plate length is at least about 100 nanometers;

and

positioning the substrate with the spatular plate portions facing the contact surface to adhere the spatular plate portions to the contact surface using intermolecular forces.

16. The method of claim 15,

for each of the at least two spatular plate portions:

the maximum plate thickness is the thickness of the thickest portion of the spatular plate portion, and

the maximum plate length is the maximum distance from a point on the boundary of the spatular plate portion to a boundary of the node measured on the line in a transverse plane that contains the node and spatular plate portion,

wherein the transverse plane contains the greatest cross-sectional area of any transverse plane containing the node and the spatular plate portion,

wherein the cross-sectional area of the node in the transverse plane includes the centroid of the node, and

wherein the line is the longest line that connects two points on the boundaries of the at least two spatular plate portions through the centroid.