Radiation Directing Layer with Conductive Nanoshells
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Solution Overview
Problem
Conventional windows with inert gas insulation and low emissivity coatings reflect or transmit radiation without directing it effectively, leading to wasted visible radiation and inefficient infrared radiation management, resulting in increased building operating costs and thermal inefficiency.
Innovation Solution
The development of windows with nano-radiators and radiation directing layers comprising conductive nanoshells that can redirect visible and infrared radiation by aligning conductive shells on substrates with different thermal expansion coefficients, allowing for wavelength-dependent redirection of radiation to optimize its entry and exit through the windows.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If conventional windows use inert gas insulation and low emissivity coatings to reduce heat transfer, then thermal efficiency is improved, but the windows cannot redirect visible or infrared radiation into the building effectively, resulting in wasted visible radiation and increased need for artificial lighting
Solution Approach 1:
The window is segmented into multiple functional layers: inert gas insulation layer for thermal efficiency, low emissivity coatings for infrared reflection, and photovoltaic cells for converting visible radiation to electricity. Each layer performs a specific function, allowing the window to simultaneously reduce heat transfer and capture visible radiation energy.
Solution Approach 2:
The window structure is designed to perform multiple functions: thermal insulation through inert gas, infrared radiation management through low emissivity coatings, and visible radiation conversion through photovoltaic cells. This multi-functional design resolves the contradiction by making the window both thermally efficient and capable of utilizing visible radiation.
2Loss of energy
If low emissivity coatings reflect infrared radiation to promote thermal efficiency, then heat loss is reduced, but the coatings cannot admit or reject infrared radiation based on interior or exterior temperatures, resulting in wasted infrared radiation that could warm interior spaces
Solution Approach 1:
The window incorporates thermochromic materials that dynamically change their optical properties in response to temperature changes. When the interior becomes too warm, the materials automatically adjust to reflect infrared radiation; when cooler, they allow infrared transmission to warm interior spaces. This dynamic adaptation resolves the contradiction between thermal efficiency and temperature-responsive control.
Solution Approach 2:
The low emissivity coatings are enhanced with temperature-dependent materials whose infrared transmission properties change based on temperature parameters. This allows the window to automatically adjust infrared radiation management according to interior and exterior temperature conditions, enabling both thermal efficiency and adaptive control.
3Illumination intensity
If visible radiation enters the building at inconvenient angles through conventional windows, then illumination is provided, but light shades are needed to block entry and avoid glare, resulting in wasted useful visible radiation and increased building operating cost
Solution Approach 1:
The photovoltaic cells convert visible radiation that would otherwise cause glare or require blocking into electrical energy. By transforming the potentially harmful high-angle visible radiation into useful electricity, the window eliminates the need for light shades while reducing building operating costs through energy generation.
Solution Approach 2:
The mechanical light shade system is replaced with photovoltaic cells that automatically manage visible radiation. Instead of using mechanical shades to block inconvenient angles of visible radiation, the photovoltaic cells convert this radiation into electricity, eliminating the need for mechanical control systems and reducing operating costs.
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
This solution enables the efficient redirection of visible and infrared radiation, reducing the need for artificial lighting and improving thermal efficiency by allowing selective admission or rejection of radiation based on temperature, thereby lowering building operating costs and enhancing energy management.
Implementation Method 1
a radiation directing layer comprising a plurality of conductive nanoshells... configured so that radiation incident in a first direction is directed so as to propagate along a second direction different from the first layer based on an orientation direction of the conductive nanoshells
Implementation Method 2
the substrate includes a first layer and a second layer having different coefficients of thermal expansion and configured so that a thermal expansion of the first layer produces buckling of the second layer
Implementation Method 3
thermal expansion of the first layer produces buckling of the second layer
Implementation Method 4
Some windows also include so-called low emissivity coatings that reflect infrared radiant so that infrared radiation is not efficiently coupled through the window
Implementation Method 5
the space between filled with an inert gas. This construction reduces heat transfer through the window
Data Source
AI summary
Conductive nanoshells are oriented so as to redirect incident radiation as a function of wavelength. Nanoshells can be formed on templates such as nanospheres or gratings and embedded in an elastomeric layer. In some examples, conductive nanoshells are coupled to a layer that is configured to unbuckle and buckle as a function of temperature, so that radiation in one or more wavelength ranges is directed differently at different temperatures. Building windows can include such layers to that infrared radiation is reflected on warm days and directed into a building on cool days. Such layers can also direct incident visible radiation to a room ceiling so as to enhance interior lighting.