Patterned 3D Photonic Crystal Liquid Selective Infiltration

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Solution Overview

Problem

Existing photonic structures with uniform surface properties face challenges in selectively interacting with liquids, limiting their ability to dynamically change reflectance spectra and exhibit encrypted messages.

Innovation Solution

A porous three-dimensional photonic crystal with patterned surface regions, each functionalized with distinct groups that attract different liquids, allowing for selective infiltration and visible color changes, enabling the encoding of messages and differentiation of solvents.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If photonic structures have uniform surface properties, then manufacturing is simpler, but the ability to selectively interact with different liquids is limited

Engineering Contradiction:
Improveselective interaction with liquidsVSAvoidsurface property patterning
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies local quality by functionalizing different regions of the photonic crystal with distinct surface properties (hydrophilic, hydrophobic, lyophobic, lyophilic groups) to enable selective liquid infiltration in specific areas, creating spatially differentiated interactions with various liquids

Inventive Principle:
Principle #3Local quality

2Loss of information

If photonic structures have uniform surface properties, then device complexity is reduced, but encrypted message capability is lost

Engineering Contradiction:
Improveencrypted message revelationVSAvoidpatterned functional groups
Core Design Contradiction:
Loss of informationVSDevice complexity

Solution Approach 1:

The patent encodes information by patterning specific regions with functional groups that respond to particular liquids, creating hidden messages that are revealed only when the corresponding liquid infiltrates those specific regions, thereby converting spatial patterns into information carriers

Inventive Principle:
Principle #3Local quality

3Adaptability or versatility

If photonic structures have uniform surface properties, then manufacturing precision requirements are lower, but reflectance spectrum dynamic manipulation is limited

Engineering Contradiction:
Improvereflectance spectrum manipulationVSAvoidfunctional group patterning
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The patent enables dynamic reflectance spectrum manipulation by creating local regions with different surface energies that selectively attract or repel liquids, causing spatially varying refractive index changes that dynamically tune the overall reflectance spectrum based on liquid infiltration patterns

Inventive Principle:
Principle #3Local quality

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 structure effectively changes its reflectance spectrum upon liquid infiltration, allowing for encrypted message revelation and solvent identification, enhancing optical response and functional versatility.

Implementation Method 1

the first functional group attracts a first liquid differently than the second functional group

Methodology Applied
Scientific EffectAdhesion: Adhesive

Implementation Method 2

Three dimensional (3D) photonic crystals (PCs), materials with a 3D-periodic variation in refractive index, have been the subject of extensivescientific interest

Methodology Applied
Scientific EffectPhotonic crystal effect: Photonic Crystal

Implementation Method 3

Infiltration and inversion of porous 3D photonic crystals with materials that are capable of dynamic actuation has produced a broad class of PCs with structural colors that can be dynamically manipulated

Methodology Applied
Scientific EffectRefraction: Refraction

Data Source

PatentEP2646807B1Manipulation of fluids in three-dimensional porous photonic structures with patterned surface properties
Publication Date: 2022.07.20 PRESIDENT & FELLOWS OF HARVARD COLLEGE
  • EP2646807B1 patent drawingFigure 1
  • EP2646807B1 patent drawingFigure 2
  • EP2646807B1 patent drawingFigure 3

AI summary

A three-dimensional porous photonic structure, whose internal pore surfaces can be provided with desired surface properties in a spatially selective manner with arbitrary patterns, and methods for making the same are described. When exposed to a fluid (e.g., via immersion or wicking), the fluid can selectively penetrate the regions of the structure with compatible surface properties. Broad applications, for example in security, encryption and document authentication, as well as in areas such as simple microfluidics and diagnostics, are anticipated.