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Color Control Technology using Candy Light-emitting Principle

  • 조회. 450
  • 등록일. 2016.08.30
  • 작성자. Administrator

Color Control Technology using Candy Light-emitting Principle






Research

team led by Dr. Soon Moon Jeong developed a mechanoluminescence color control

technology that can change green light to red light by simulating the candy

light-emitting principle. The technology is expected to be used for displays

and lights that require no external electricity. 



 



*

mechanoluminescence: a method of light emission that requires no external

electric power and which applies a mechanical force to a material to cause motion

and the recombination of electrons in the material that in turn transmits

mechanical energy to light energy. 



 



The research team noted that blue light is emitted when

wintergreen-flavored candy (ex. Lifesavers) is bitten or smashed. In general,

it is known that mechanoluminescence in the ultraviolet region is generated

when the sugar component in the candy is broken. Natural vegetable oil is a

material that generates a blue color by absorbing ultraviolet, thus

wintergreen-flavored candy containing natural vegetable oil emits a blue light

when it is smashed. 








The research team thus combined this phenomenon with

mechanoluminescence research and developed a color control technology that

allows the existing green light in the mechanoluminescence material to be

absorbed and red light to be generated by mixing single green

mechanoluminescence material and organic fluorescent dye.














When rubbing a substrate that is coated with organic

fluorescent dye with a mixture of mechanoluminescence materials (ex. ZnS and PDMS)

and silicone rubber, the mechanoluminescence materials that are heavier than the

silicon rubber will sink to the bottom of the substrate, while the silicon

rubber is being hardened and the organic fluorescent dye will be evenly spread over

its top forming a natural double-layered structure. An experiment confirmed

that when mechanical force is applied on the substrate, the light-emitting

layer in the mechanoluminescence material generates green light, and the color

conversion layer where the organic fluorescent dye is spread on the rubber converts

this green light into red light. 



 






Through these experiments, the team proved that it is

possible to express a variety of colors depending on the mixture ratio of the single

mechanoluminescence materials and organic fluorescent dye. Color conversion

efficiency can also be increased through the diffusion of the organic

fluorescent dye. Further, this structure can be applied to an electric field

that generates light electrically, so the team also developed a hybrid element

implementing patterns that enable mechanoluminescence light-emission and

electrical light emission simultaneously yet independently.











In contrast to existing studies that relied on the

development of mechanoluminescence materials based on the fact that

mechanoluminescence material affects the color of light produced, the findings

of this study have been evaluated highly in the sense that they pioneered

mechanoluminescence color control technology by enabling a larger variety of

color expression by combining organic fluorescent dye.



 



This mechanoluminescence light-emitting phenomenon can

be applied to displays, lights, and sensors without external electric power;

thus, it is expected to be used in the development of environment-friendly

displays that cause no energy or environmental problems. 



 



Dr. Soon Moon Jeong from Division of Nano and Energy

Convergence Research said, “The core of this study is that we discovered that a

variety of colors can be generated by combining mechanoluminescence materials

as well as organic fluorescent dye that are widely and commonly used. I’ll

continue to conduct research that improves energy and environmental issues by

using mechanoluminescence phenomena.”



 






This research outcome was published in Advanced Functional Materials, a world-renowned

international journal in the materials science field, on July 19, 2016.






Journal Reference



Soon Moon Jeong, Seongkyu Song, et.

al., “Mechanoluminescence Color Conversion by Spontaneous

Fluorescent-Dye-Diffusion in Elastomeric Zinc Sulfide Composite”, Advanced

Functional Materials 2016.





http://onlinelibrary.wiley.com/doi/10.1002/adfm.201601461/abstract