Magnetic Color-Changeable Microcapsules for Stable Photonic Crystal Arrangement
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Solution Overview
Problem
Conventional printing methods using magnetic-color-changeable microcapsules face challenges in achieving stable color retention after curing, as the arrangement of photonic crystals can be disturbed by external magnetic fields, and the curable solvent hinders the movement of nanoparticles, making it difficult to achieve desired color arrangements.
Innovation Solution
A composition comprising magnetic-color-changeable microcapsules with a curable solvent having a specific weight-average molecular weight and viscosity, along with a magnetic field generation unit and energy regulation unit, is used to control the arrangement of electrically charged nanoparticles within the microcapsules, ensuring stable color retention even after exposure to strong magnetic fields.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a curable solvent is used to disperse photonic crystals in magnetic-color-changeable microcapsules, then the composition can be jetted and printed onto a printing medium, but the curable solvent inhibits the movement of photonic crystals making it difficult to achieve desired color arrangements
Solution Approach 1:
The patent applies a magnetic field before the curable solvent fully cures to arrange the photonic crystals in the desired configuration. This preliminary action occurs while the solvent is still in a mobile state, allowing crystal movement, but before curing locks the arrangement in place, thus resolving the contradiction between printability and arrangement stability.
2Adaptability or versatility
If photonic crystals are arranged by applying a magnetic field, then color-changing effects are achieved, but the arrangement may be disturbed by external magnetic fields even after curing
Solution Approach 1:
The patent utilizes the phase transition of the curable solvent from liquid to solid state through curing. In the liquid state, photonic crystals can move and rearrange in response to magnetic fields for color changing. After curing transitions to solid state, the crystals are locked in position, providing color stability while maintaining the ability to change color when needed through controlled magnetic field application.
3Device complexity
If multiple colors are printed using a single cartridge with magnetic-color-changeable microcapsules, then device complexity is reduced, but manufacturing precision of color arrangement becomes more difficult
Solution Approach 1:
The patent changes the magnetic field parameters (strength, direction, timing) to control photonic crystal arrangement for different colors. By varying these parameters during the printing process, a single cartridge can produce multiple colors with precise arrangements, reducing device complexity while maintaining manufacturing precision through parameter control rather than physical structure.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The composition exhibits stable color changes and retention, suitable for fast curing and repeated exposure to magnetic fields, enhancing the performance of printing devices like handheld writing instruments by maintaining color stability and sharpness.
Implementation Method 1
a curable solvent having a specific weight-average molecular weight and viscosity
Implementation Method 2
a magnetic field generation unit and energy regulation unit, is used to control the arrangement of electrically charged nanoparticles within the microcapsules
Implementation Method 3
based on the principle by which photonic crystals that constitute the magnetic-color-changeable microcapsules are arranged differently depending on the magnetic field strength to thereby vary the wavelength of reflected light
Implementation Method 4
a curable solvent surrounding the photonic crystals is cured and, thus, the mobility of the arranged photonic crystals is reduced
Data Source
Figure 1(a)~1(b)
Figure 2(a)~2(b)
Figure 3~4d
AI summary
This disclosure relates to a printing device for printing or dispensing a curable printing composition which is capable of changing color in response to the application of a magnetic field in the non-cured state. The printing device may be a handheld device such as a portable pen. The present disclosure further relates to curable compositions, cartridges and methods which may be used in combination with the aforementioned printing devices or in other applications.