Mold fabrication method for gecko-inspired adhesives

Patent metadata

Field	Value
Publication number	US-9908266-B2
Application number	US-201514924252-A
Country	US
Kind code	B2
Filing date	Oct 27, 2015
Priority date	Apr 20, 2011
Publication date	Mar 6, 2018
Grant date	Mar 6, 2018

Abstract

A method of forming synthetic dry adhesives is provided that includes using a combined wedge indenting and orthogonal machining process to form tapered mold cavities in a mold, filling the tapered mold cavities with an elastomeric adhesive, curing the elastomeric adhesive in the tapered mold cavities, and removing the elastomeric adhesive from the mold, where a plurality of tapered lamellar ridges extend from a surface of the elastomeric adhesive.

First claim

What is claimed:

1. A method of forming synthetic dry adhesives, comprising:
a. using a combined wedge indenting and orthogonal machining process to form tapered mold cavities in a mold;
b. filling said tapered mold cavities with an elastomeric adhesive;
c. curing said elastomeric adhesive in said tapered mold cavities; and
d. removing said elastomeric adhesive from said mold, wherein a plurality of tapered lamellar ridges extend from a surface of said elastomeric adhesive, wherein said wedge indenting and orthogonal machining process comprises using a wedge-shape tool, wherein a centerline of said wedge-shaped tool is set at an angle λ with respect to a top surface of said mold, wherein a trajectory of said tool is at an intermediate angle θ with respect to a top surface of said mold, wherein said angle θ is in a range of 0<θ<2.

2. The method according to claim 1 , wherein said mold comprises a homogeneous wax composition having a Young's modulus to yield stress ratio E/Y greater than 100.

3. The method according to claim 1 , wherein said wedge-shaped tool comprises at least a primary bevel.

4. The method according to claim 1 , wherein said wedge-shaped tool comprises a primary bevel, a secondary bevel and a tertiary bevel.

5. The method according to claim 1 , wherein said wedge-shaped tool comprises a lubricated surface.

6. The method according to claim 1 , wherein said wedge-shaped tool is moved along a 2-dimensional or 3-dimensional trajectory into said mold until a tip of said wedge-shaped tool reaches said depth t below a top surface of said mold.

7. The method according to claim 1 , wherein a trajectory of said wedge-shaped tool is controlled to move displaced mold material in a desired direction, wherein said mold cavities are desirably spaced and a shape of said cavities is controlled.

8. The method according to claim 1 , wherein said elastomeric adhesive comprises an elastomer selected from the group consisting of silicones, polyurethanes, and polypropylene.

9. The method according to claim 1 , wherein said substrate surface comprises a smooth or textured surface, wherein said surface is disposed to transfer a desired smoothness or desired texture to a film of said uncured elastomeric material as said uncured elastomeric material cures.

10. The method according to claim 1 , wherein a siping step is used when said adhesive is de-molded, wherein said siping step comprises a cut perpendicular to said extending tapered lamellar ridge at a desired frequency to improve adhesion on textured surfaces having micro-scale roughness, wherein independent adhesive sections of said extending tapered lamellar ridge conform to said textured surface.

Assignees

• Univ Leland Stanford Junior

Inventors

• Cutkosky Mark R
• Day Paul S
• Eason Eric V

Classifications

• B29C33/424

  Moulding surfaces provided with means for marking or patterning (for injection moulding B29C45/372) · CPC title

• Y10T428/2457

  Parallel ribs and/or grooves · CPC title

• B29C33/3842 Primary

  Manufacturing moulds, e.g. shaping the mould surface by machining · CPC title

• B29K2083/00

  Use of polymers having silicon, with or without sulfur, nitrogen, oxygen, or carbon only, in the main chain, as moulding material · CPC title

• C09J183/04

  Polysiloxanes · CPC title