Nanofiber web piezoelectric material obtained by electrospinning polylactic acid, method of producing same, piezoelectric sensor comprising same, and method of manufacturing the piezoelectric sensor

Patent metadata

Field	Value
Publication number	US-2016190427-A1
Application number	US-201514979512-A
Country	US
Kind code	A1
Filing date	Dec 27, 2015
Priority date	Dec 30, 2014
Publication date	Jun 30, 2016
Grant date	—

Abstract

Disclosed are a nanofiber web piezoelectric material and a method of producing the same, wherein a spinning solution of polylactic acid (PLA) in a solvent is electrospun, yielding a nanofiber web, thereby exhibiting piezoelectric properties without additional drawing. This piezoelectric material is remarkably cost-effective, can exhibit superior piezoelectric properties, can be used to manufacture inexpensive piezoelectric products, and obviates any additional drawing because the PLA chain is drawn during electrospinning. The drawing force induced by a high electric field between the needle and the collector enables the formation of 3 1 helical β-crystal chains in a uniaxial direction even without any other drawing process. This PLA nanofiber web is very thin and flexible, the PLA chains are effectively aligned in an electric field direction due to the high DC voltage used for electrospinning, and helical β conformation is easily formed in a single process using electrospinning.

First claim

What is claimed is:

1 . A nanofiber web piezoelectric material, obtained by electrospinning a spinning solution of polylactic acid in a solvent.

2 . The piezoelectric material of claim 1 , wherein at least 80% of a monomer for the polylactic acid comprises an L-isomer or a D-isomer.

3 . The piezoelectric material of claim 1 , wherein the solvent is a mixture comprising chloroform and one of N,N-dimethylacetamide (DMAc), N,N-dimethylformamide (DMF) and dimethylsulfoxide (DMSO).

4 . The piezoelectric material of claim 3 , wherein the mixture comprises chloroform and one of N,N-dimethylacetamide (DMAc), N,N-dimethylformamide (DMF) and dimethylsulfoxide (DMSO) mixed at a volume ratio of 2:1 to 4:1.

5 . The piezoelectric material of claim 4 , wherein the spinning solution is prepared by dissolving 5 to 20 wt % of polylactic acid in the solvent.

6 . A piezoelectric sensor, comprising the piezoelectric material of claim 1 and electrodes.

7 . The piezoelectric sensor of claim 6 , wherein the piezoelectric material is folded at least two times and stacked so that same surface portions thereof face each other,
the electrodes are provided between the folded surface portions of the stacked piezoelectric material and on an uppermost surface and a lowermost surface thereof, and the electrodes, in contact with the same surface portions based on a surface of the unfolded piezoelectric material, are electrically connected to each other.

8 . The piezoelectric sensor of claim 6 , comprising:
a sensing unit including the piezoelectric material and electrodes formed on both surfaces of the piezoelectric material; and an elastic layer for wrapping the sensing unit.

9 . The piezoelectric sensor of claim 8 , wherein the elastic layer comprises silicone rubber.

10 . A method of producing a piezoelectric nanofiber web, comprising:
dissolving polylactic acid in a solvent, thus preparing a spinning solution; and electrospinning the spinning solution, yielding a nanofiber web.

11 . The method of claim 10 , wherein at least 80% of a monomer for the polylactic acid comprises an L-isomer or a D-isomer.

12 . The method of claim 10 , wherein the solvent is a mixture comprising chloroform and one of N,N-dimethylacetamide (DMAc), N,N-dimethylformamide (DMF) and dimethylsulfoxide (DMSO).

13 . The method of claim 12 , wherein the mixture comprises chloroform and one of N,N-dimethylacetamide (DMAc), N,N-dimethylformamide (DMF) and dimethylsulfoxide (DMSO) mixed at a volume ratio of 2:1 to 4:1.

14 . The method of claim 13 , wherein the spinning solution is prepared by dissolving 5 to 20 wt % of polylactic acid in the solvent.

Assignees

• Univ Kyung Hee Univ Ind Coop Group

Inventors

• Kim Kap Jin
• Lee Sol Jee
• Arun Anand Prabu
• Ponnan Sathiyanathan

Classifications

• B29C47/0076

  Operations & Transport · mapped topic

• H01L41/082 Primary

  Electricity · mapped topic

• H01L41/1132

  Electricity · mapped topic

• B29C47/0021

  Operations & Transport · mapped topic

• B29K2067/046

  PLA, i.e. polylactic acid or polylactide · CPC title