Adhesive microstructure and method of forming same

• US 7,828,982 B2
• Filed: 06/11/2007
• Issued: 11/09/2010
• Est. Priority Date: 12/20/1999
• Status: Expired due to Term

• Current Assignee: Board of Trustees of the Leland Stanford Junior University (Stanford Management Co.)
• Original Assignee: Regents of the University of California (University of California)
• Inventors: Kenny, Thomas, Full, Robert J., Fearing, Ronald S., Autumn, Kellar
• Primary Examiner(s): Tran; Binh X
• Application Number:
  US11/811,882
• Publication Number:
  US 20080073323A1
• Time in Patent Office: 1,247 Days
• Field of Search: 216/7, 216/11, 427/208.2, 427/208.4, 427/208.6
• US Class Current: 216/7
• CPC Class Codes: C09J 2301/31 the adhesive effect being based on a Gecko structure
• CPC Class Codes: C09J 5/00 Adhesive processes in general; Adhesive processes not provided for elsewhere, e.g. relating to primers
• CPC Class Codes: C09J 7/00 Adhesives in the form of films or foils
• CPC Class Codes: G01N 19/04 Measuring adhesive force between materials, e.g. of sealing tape, of coating
• CPC Class Codes: G01N 2203/0025 Shearing
• CPC Class Codes: G01N 2203/0286 Miniature specimen; Testing on microregions of a specimen
• CPC Class Codes: G01N 2203/0623 using piezoelectric gauges
• CPC Class Codes: G01N 3/24 by applying steady shearing forces G01N3/26, G01N3/28 take precedence
• CPC Class Codes: Y10T 156/10 Methods of surface bonding and/or assembly therefor
• CPC Class Codes: Y10T 428/28 Web or sheet containing structurally defined element or component and having an adhesive outermost layer
• CPC Class Codes: Y10T 428/2973 Particular cross section
• CPC Class Codes: Y10T 428/2976 Longitudinally varying
• CPC Class Codes: Y10T 428/2978 Surface characteristic
• CPC Class Codes: Y10T 428/298 Physical dimension

Abstract

A method of forming an adhesive force includes removing a seta from a living specimen, attaching the seta to a substrate, and applying the seta to a surface so as to establish an adhesive force between the substrate and the surface. The seta is applied to the surface with a force perpendicular to the surface. The seta is then pulled with a force parallel to the surface so as to preload the adhesive force of the seta.

Claims

1. A method of fabricating a microstructure, comprising:

obtaining a substrate;

forming a plurality of shafts, each shaft having a first end connected to the substrate and a second end opposite the first end, each shaft having a length of less than 500 microns, and each shaft having a diameter of between 0.01 and 0.1 times the length of the shaft; and

forming a protrusion at the second end of each shaft, each protrusion having a width of less than 10 microns, and each protrusion capable of providing a substantially parallel adhesive force at a surface of between about 20 and 8,000 nano-Newtons.

2. The method of claim 1, where the plurality of shafts are formed using a sandwich of nitride and oxide.

3. The method of claim 1, wherein forming a protrusion includes seeding the second end of each shaft to form the protrusion.

4. The method of claim 1, wherein forming a protrusion includes roughening the second end of each shaft to form the protrusion.

5. The method of claim 1, wherein forming a protrusion includes etching the second end of each shaft to form the protrusion.

6. The method of claim 1, wherein forming a protrusion includes embossing the second end of each shaft to form the protrusion.

7. The method of claim 1, wherein the plurality of shafts are formed using a sandwich of polymer layers.

8. The method of claim 7, wherein the sandwich of polymer layers includes a spin-cast polymer material selected from the group consisting of photoresist, polyimide, glass, and epoxy-based compounds.

9. The method of claim 7, wherein the sandwich of polymer layers includes a spray-deposited polymer material selected from the group consisting of photoresist, polyimide, glass, and epoxy-based compounds.

10. The method of claim 7, wherein the sandwich of polymer layers includes ultra violet curable epoxies.

11. The method of claim 1, wherein forming a plurality of shafts includes etching the substrate to form molding structures defining the length and shape of the plurality of shafts.

12. The method of claim 11, further comprising:

coating the substrate with oxide and nitride layers.

13. The method of claim 11, further comprising:

coating the substrate with a material selected from the group consisting of photoresist, polyimide, glass, and epoxy-based compounds.

14. A method of fabricating a microstructure, comprising:

obtaining a substrate;

forming a plurality of shafts, each shaft having a first end connected to the substrate and a second end opposite the first end, each shaft having a length of less than 500 microns, and each shaft having a diameter of between 0.01 and 0.1 times the length of the shaft; and

forming a plurality of protrusions at the second end of each shaft, each protrusion having a width of less than 10 microns, and each protrusion capable of providing a substantially parallel adhesive force at a surface of between about 20 and 8,000 nano-Newtons.

15. The method of claim 14, wherein forming a protrusion includes seeding the second end of each shaft to form the protrusion.

16. The method of claim 14, wherein forming a protrusion includes roughening the second end of each shaft to form the protrusion.

17. The method of claim 14, wherein forming a protrusion includes etching the second end of each shaft to form the protrusion.

18. A method of fabricating a microstructure, comprising:

obtaining a substrate;

forming a plurality of shafts by etching the substrate to form molding structures defining the length and shape of the plurality of shafts, each shaft having a first end connected to the substrate and a second end opposite the first end, each shaft having a length of less than 500 microns, and each shaft having a diameter of between 0.01 and 0.1 times the length of the shaft; and

forming a plurality of protrusions at the second end of each shaft, each protrusion having a width of less than 10 microns.

19. The method of claim 18, wherein forming a protrusion includes seeding the second end of each shaft to form the protrusion.

20. The method of claim 18, wherein forming a protrusion includes roughening the second end of each shaft to form the protrusion.

21. The method of claim 18, wherein forming a protrusion includes etching the second end of each shaft to form the protrusion.