Bio-inspired, highly stretchable and conductive dry adhesive patch, method of manufacturing the same and wearable device including the same

Patent metadata

Field	Value
Publication number	US-2020337640-A1
Application number	US-201816486245-A
Country	US
Kind code	A1
Filing date	Feb 5, 2018
Priority date	Feb 16, 2017
Publication date	Oct 29, 2020
Grant date	—

Abstract

In a method of manufacturing a biomimetic highly stretchable conductive dry adhesive patch, a mold including a plurality of holes is provided by etching a semiconductor substrate including an insulation layer based on a footing effect. A conductive polymer composite is provided by dispersing mixed conductive fillers in a liquid elastomer. The mixed conductive fillers are formed by mixing one-dimensional conductive fillers and two-dimensional conductive fillers. The conductive polymer composite is applied on the mold such that the conductive polymer composite is injected into the plurality of holes. A conductive dry adhesive structure including a plurality of micropillars corresponding to the plurality of holes is obtained by performing a post-treatment on the conductive polymer composite applied on the mold and by removing the mold. Each of the plurality of micropillars includes a body portion and a tip portion. The tip portion has a spatula shape, is formed on the body portion, and has an area larger than that of the body portion in a plan view.

First claim

What is claimed is:

1 . A method of manufacturing a biomimetic highly stretchable conductive dry adhesive patch, the method comprising:
providing a mold including a plurality of holes by etching a semiconductor substrate including an insulation layer based on a footing effect; providing a conductive polymer composite by dispersing mixed conductive fillers in a liquid elastomer, the mixed conductive fillers being formed by mixing one-dimensional conductive fillers and two-dimensional conductive fillers; applying the conductive polymer composite on the mold such that the conductive polymer composite is injected into the plurality of holes; and obtaining a conductive dry adhesive structure including a plurality of micropillars corresponding to the plurality of holes by performing a post-treatment on the conductive polymer composite applied on the mold and by removing the mold, wherein each of the plurality of micropillars includes: a body portion; and a tip portion having a spatula shape, formed on the body portion, and having an area larger than that of the body portion in a plan view.

2 . The method of claim 1 , wherein an amount of the one-dimensional conductive fillers included in the mixed conductive fillers is greater than an amount of the two-dimensional conductive fillers included in the mixed conductive fillers.

3 . The method of claim 2 , wherein a ratio of the one-dimensional conductive fillers and the two-dimensional conductive fillers in the mixed conductive fillers is within a range of about 8:2 to about 9.99:0.01.

4 . The method of claim 1 , wherein an amount of the mixed conductive fillers dispersed in the liquid elastomer is less than or equal to about 1.0 weight percent (wt %) based on a total weight of the conductive polymer composite.

5 . The method of claim 1 , wherein an aspect ratio obtained by dividing a height of each of the plurality of micropillars by a width of each of the plurality of micropillars is within a range of about 2 to about 4.

6 . The method of claim 1 , wherein:
each of the body portion and the tip portion has a cylindrical shape, the body portion is formed on an elastic substrate including the conductive polymer composite, and has a first diameter and a first thickness, and the tip portion is formed on the body portion, and has a second diameter larger than the first diameter and a second thickness smaller than the first thickness.

7 . The method of claim 1 , wherein each of the one-dimensional conductive fillers and the two-dimensional conductive fillers include a carbon-based nanoconductive material.

8 . The method of claim 7 , wherein the one-dimensional conductive fillers include a conductive material based on carbon nanotube (CNT).

9 . The method of claim 7 , wherein the two-dimensional conductive fillers include a conductive material based on a material selected from the group consisting of graphene, carbon black (CB) and graphite.

10 . The method of claim 1 , wherein the one-dimensional conductive fillers include a conductive material based on silver nanowire.

11 . The method of claim 1 , wherein the liquid elastomer includes a material selected from the group consisting of polydimethylsiloxane (PDMS), PDMS modified urethane acrylate (PUA), perfluoropolyether (PFPE) and polyethylene (PE).

12 . The method of claim 1 , wherein providing the mold includes:
forming a photoresist layer on the semiconductor substrate, the semiconductor substrate including a bare semiconductor wafer, the insulation layer formed on the bare semiconductor wafer, and a semiconductor layer formed on the insulation layer; forming a photoresist pattern including a hole array by patterning the photoresist layer; performing an etching process on the semiconductor layer using the photoresist pattern as a mask until the insulation layer is exposed; removing the photoresist pattern; and performing a surface treatment on the mold.

13 . The method of claim 12 , wherein each of the plurality of holes includes:
a first portion formed adjacent to the insulation layer, and having a shape corresponding to the tip portion; and a second portion formed on the first portion, and having a shape corresponding to the body portion, wherein a width and a thickness of the first portion are determined based on an execution time during which the etching process is performed on the semiconductor layer.

14 . A biomimetic highly stretchable conductive dry adhesive patch, comprising:
an elastic structure formed of an elastic material, and including an elastic substrate and a plurality of micropillars formed on the elastic substrate; and mixed conductive fillers formed by mixing one-dimensional conductive fillers and two-dimensional conductive fillers, and dispersed in the elastic structure to form a conductive network, wherein each of the plurality of micropillars includes: a body portion; and a tip portion having a spatula shape, formed on the body portion, and having an area larger than that of the body portion in a plan view, and wherein a conductive dry adhesive structure is formed by the elastic structure and the mixed conductive fillers.

15 . The biomimetic highly stretchable conductive dry adhesive patch of claim 14 , wherein an amount of the one-dimensional conductive fillers included in the mixed conductive fillers is greater than an amount of the two-dimensional conductive fillers included in the mixed conductive fillers.

16 . The biomimetic highly stretchable conductive dry adhesive patch of claim 15 , wherein a ratio of the one-dimensional conductive fillers and the two-dimensional conductive fillers in the mixed conductive fillers is within a range of about 8:2 to about 9.99:0.01.

17 . The biomimetic highly stretchable conductive dry adhesive patch of claim 14 , wherein an amount of the mixed conductive fillers dispersed in the elastic structure is less than or equal to about 1.0 weight percent (wt %) based on a total weight of the elastic structure and the mixed conductive fillers.

18 . The biomimetic highly stretchable conductive dry adhesive patch of claim 14 , wherein an aspect ratio obtained by dividing a height of each of the plurality of micropillars by a width of each of the plurality of micropillars is within a range of about 2 to about 4.

19 . The biomimetic highly stretchable conductive dry adhesive patch of claim 14 , wherein:
each of the one-dimensional conductive fillers and the two-dimensional conductive fillers include a carbon-based nanoconductive material, the one-dimensional conductive fillers include a conductive material based on carbon nanotube (CNT), and the two-dimensional conductive fillers include a conductive material based on a material selected from the group consisting of graphene, carbon black (CB) and graphite.

20 . A wearable device comprising:
a biomimetic highly stretchable conductive dry adhesive patch; a measurer connected to the biomimetic highly stretchable conductive dry adhesive patch; and a processor configured to perform a predetermined data processing operation based on an output of the measurer, wherein the biomimetic highly stretchable conductive dry adhesive patch includes: an elastic structure formed of an elastic material, and including an elastic substrate and a plurality of micropillars formed on the elastic substrate; and mixed conductive fillers formed by mixing one-dimensional conductive fillers and two-dimensional conductive fillers, and dispersed in the elastic structure to form a

Assignees

• Korea Advanced Inst Sci & Tech

Inventors

• Jeon Seok-Woo
• Kim Tae-Hoon
• Cho Dong-Hwi
• Park Junyong

Classifications

• H10W72/30

  Die-attach connectors · CPC title

• H10W74/01

  Manufacture or treatment · CPC title

• H10W20/01 Primary

  Manufacture or treatment · CPC title

• H10P76/00

  Manufacture or treatment of masks on semiconductor bodies, e.g. by lithography or photolithography · CPC title

• H10P95/00

  Generic processes or apparatus for manufacture or treatments not covered by the other groups of this subclass · CPC title