Multi-Layer Laminate for Transparent Thermal Insulation
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Solution Overview
Problem
Current building and window materials lack sufficient thermal insulation while maintaining transparency, as existing heat-insulating materials are either opaque or costly due to complex vacuum structures.
Innovation Solution
A laminate structure with multiple layers of varying specific acoustic impedances, including metal oxides and nitrides, is developed, featuring a large number of thin layers with uneven thicknesses to reduce thermal conductivity and enhance insulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If vacuum glass or glass wool is used for heat insulation, then thermal insulation function is improved, but transparency is lost and cost increases
Solution Approach 1:
The patent divides the heat insulation function into multiple thin layers (10 or more layers) with different specific acoustic impedances. Each layer is thin (8 nm or less) to maintain transparency while the collective structure provides thermal insulation through phonon scattering at numerous interfaces, resolving the contradiction between insulation performance and transparency.
Solution Approach 2:
The patent uses composite material structure with alternating layers of different materials (e.g., metal oxides, metal nitrides) having different specific acoustic impedances. This composite structure scatters phonons effectively for thermal insulation while remaining transparent to visible light, avoiding the need for opaque materials like glass wool or vacuum structures.
2Loss of energy
If multiple layers with different specific acoustic impedances are used, then thermal conductivity is reduced, but manufacturing precision requirements increase
Solution Approach 1:
The patent specifies that the coefficient of variation (CV) of layer thicknesses should be 0.05 or more, meaning intentional thickness variation is allowed and even beneficial. This parameter change approach reduces the need for ultra-precise manufacturing while maintaining thermal insulation performance through phonon scattering at interfaces with varying thicknesses.
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 laminate achieves reduced thermal conductivity and improved thermal insulation, making it suitable for building and window materials, while maintaining transparency and reducing costs.
Implementation Method 1
a laminated structure including two or more kinds of layers having different specific acoustic impedances which is disposed on a substrate... the number of layers constituting the laminated structure is 10 or more... a thickness of a layer having the largest thickness among the layers constituting the laminated structure is 8 nm or less
Data Source
AI summary
Provided are a laminate including a substrate; and a laminated structure including two or more kinds of layers having different specific acoustic impedances which is disposed on the substrate, in which the number of the layers constituting the laminated structure is 10 or more, a thickness of a layer having the largest thickness among the layers constituting the laminated structure is 8 nm or less, and in the laminated structure, a CV value defined by a standard deviation of a layer thickness/average layer thickness is 0.05 or more, and a building material, a window material, and a radiation cooling device including the laminate.