Anodic Aluminum Oxide Invisible Ink for Stable Luminescence
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Solution Overview
Problem
Existing invisible inks made from organic and inorganic luminescent materials suffer from poor stability, high production costs due to the use of rare earth elements, and environmental pollution from solvents.
Innovation Solution
An invisible ink composed of anodic aluminum oxide (AAO) powder and solvents, where the AAO powder is produced through an anodic oxidation process on aluminum substrates, followed by separation and pulverization, and then mixed with silicone oil and dispersants.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If organic luminescent materials are used in invisible ink, then the ink can be produced with simpler materials, but the stability deteriorates due to decomposition and fading under high temperature or long term illumination
Solution Approach 1:
The patent replaces unstable organic luminescent materials with inorganic aluminum oxide particles that provide long-term stability and resistance to decomposition, effectively substituting short-lived organic compounds with durable inorganic materials that maintain luminescence properties over time and under various environmental conditions
2Reliability
If inorganic luminescent materials containing rare earth elements are used, then the stability is improved, but the production cost increases significantly due to low yield and expensive rare earth elements
Solution Approach 1:
The patent extracts and eliminates rare earth elements from the luminescent material composition, using pure aluminum oxide particles that can be produced through inexpensive anodization of aluminum substrates. This extraction of the expensive rare earth component while retaining the luminescent functionality directly addresses the cost-stability contradiction
Solution Approach 2:
The patent substitutes expensive inorganic luminescent materials containing rare earth elements with inexpensive aluminum oxide particles derived from common aluminum substrates, achieving a cost-effective solution that maintains stability through the use of abundant, low-cost materials
3Reliability
If inorganic luminescent materials are used, then the stability is improved, but environmental pollution increases due to the use of harmful solvents and production processes
Solution Approach 1:
The patent converts the typically harmful production process into an environmentally beneficial one by using anodization, which naturally forms aluminum oxide layers on aluminum substrates. This process utilizes oxygen from the air and electrical energy to create the luminescent material, eliminating the need for harmful chemical solvents and production processes while maintaining stability
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 AAO-based invisible ink exhibits stable luminescence properties, is resistant to decomposition, and has a lower production cost without the need for rare earth elements, while also minimizing environmental impact.
Implementation Method 1
An invisible ink or pigment is colorless and invisible under visible light until but visible under specific conditions such as UV radiation
Implementation Method 2
the AAO-based invisible ink exhibits stable luminescence properties
Implementation Method 3
carrying out an anodic oxidation process on the aluminum substrate at least once to form an anodic aluminum oxide (AAO) layer on a surface of the aluminum substrate
Data Source
AI summary
An invisible ink and a method of making the same are revealed. The invisible ink includes anodic aluminum oxide (AAO) powder and at least one solvent. The method of making the invisible ink includes the steps of taking an aluminum substrate and carrying out anodic oxidation on the aluminum substrate at least once to form an anodic aluminum oxide (AAO) layer on a surface of the aluminum substrate, separating the AAO layer from the aluminum substrate and pulverizing the separated AAO layer to get AAO powder, and adding the AAO powder into a solvent to obtain the invisible ink.