Electrochromic Device Selective Heating via Sheet Resistance
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Solution Overview
Problem
Electrochromic devices face challenges in efficiently switching transmission levels due to temperature-dependent performance, requiring substantial electrical power for heating, which can be wasteful and non-uniform, especially when rapid or frequent switching is needed.
Innovation Solution
The electrochromic device is configured to selectively heat specific regions of the conductive layer using varying sheet resistances, geometric structures, and electrode configurations, allowing for targeted heating of the EC film stack, reducing power consumption and ensuring uniformity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the EC stack is heated to ensure acceptable switching speeds, then the switching speed is improved, but the electrical power consumption increases substantially
Solution Approach 1:
The patent divides the heating function into separate heating electrodes that can be independently controlled for different regions of the EC stack. This allows selective heating of only those portions that require temperature elevation for acceptable switching performance, rather than heating the entire stack uniformly, thereby reducing overall power consumption while maintaining switching speed where needed.
Solution Approach 2:
The patent implements non-uniform heating by applying different heating levels to different regions of the EC stack based on local performance requirements. Regions with slower switching kinetics receive higher heating, while regions that switch adequately receive minimal or no heating, optimizing the balance between switching speed and power consumption.
2Loss of time
If the EC stack is heated rapidly to enable short-notice transmission switching, then the switching responsiveness is improved, but the electrical power expenditure increases substantially
Solution Approach 1:
The patent maintains the EC stack regions in a pre-heated state during idle periods, so that when transmission switching is required, the heating is already underway or complete, enabling rapid response without requiring substantial power expenditure at the moment of switching demand.
Solution Approach 2:
The patent employs periodic or pulsed heating cycles to maintain acceptable switching performance. Instead of continuous heating, the system applies heating intermittently to keep the EC stack regions at temperatures that enable acceptable switching speeds, reducing overall power expenditure while maintaining responsiveness.
3Stability of the object's composition
If uniform heating of the EC stack is applied, then the temperature distribution is improved, but the power consumption increases and switching uniformity across regions may be compromised
Solution Approach 1:
The patent implements non-uniform heating by applying different heating levels to different regions of the EC stack based on local performance requirements. Regions with slower switching kinetics receive higher heating, while regions that switch adequately receive minimal or no heating, optimizing the balance between switching speed and power consumption.
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 approach enhances the switching speed and uniformity of the electrochromic device while minimizing electrical power usage, allowing for efficient and controlled transmission level changes in different regions of the EC stack.
Implementation Method 1
heating an EC stack can require substantial amounts of electrical power
Data Source
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AI summary
An electrochromic device is structured to selectively heat one or more particular regions of a conductive layer of the electrochromic device. An electrical potential difference can be induced across the conductive layer to heat one or more layer regions. The conductive layer can be one of at least two conductive layers on opposite sides of an electrochromic film stack, and an electrical potential difference can be induced between the conductive layers to cause at least some of the electrochromic film stack to change transmission levels. The conductive layer can include regions with different sheet resistances, so that one or more regions are structured to generate more heat than other regions of the conductive layer when an electrical potential difference is induced across the conductive layer. Separate layer regions can include separate chemical species. The conductive layer can be geometrically structured so that some layer regions have a greater sheet resistance than other regions.