Electrically Grated Carbon Foam Resistivity Gradient
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing carbon foam materials lack the ability to create a gradient in electrical resistivity through their thickness, which is necessary for advanced applications such as radar absorption and electromagnetic interference shielding.
Innovation Solution
A method to produce electrically gradated carbon foam materials by controlling the heating temperatures and times of different surfaces of the carbon foam body, resulting in significantly varying electrical resistivity values between the surfaces, with the resistivity near the second surface being at least twice that of the first surface, and potentially ranging from 2 to 1E+8 times greater.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If carbon foam material is used with uniform composition, then manufacturing is simple, but electrical resistivity cannot be gradient-controlled for advanced applications
Solution Approach 1:
The patent applies local quality by creating different electrical resistivity properties at different locations within the carbon foam body. Specifically, the first surface is heated to a first temperature to achieve a first electrical resistivity, while the second surface is heated to a second temperature to achieve a second electrical resistivity that is at least twice that of the first surface. This spatial variation in electrical properties enables gradient control for radar absorption and EMI shielding applications.
Solution Approach 2:
The patent implements parameter changes by varying the heating temperatures applied to different surfaces of the carbon foam body. The first surface is heated to a first temperature and the second surface is heated to a second temperature, where the temperature difference creates the desired electrical resistivity gradient. This approach allows precise control of electrical properties through thermal parameter manipulation.
2Manufacturing precision
If uniform heating is applied to carbon foam, then processing is simple, but electrical resistivity gradient cannot be achieved
Solution Approach 1:
The patent applies local quality by creating different electrical resistivity properties at different locations within the carbon foam body. Specifically, the first surface is heated to a first temperature to achieve a first electrical resistivity, while the second surface is heated to a second temperature to achieve a second electrical resistivity that is at least twice that of the first surface. This spatial variation in electrical properties enables gradient control for radar absorption and EMI shielding applications.
Solution Approach 2:
The patent implements parameter changes by varying the heating temperatures applied to different surfaces of the carbon foam body. The first surface is heated to a first temperature and the second surface is heated to a second temperature, where the temperature difference creates the desired electrical resistivity gradient. This approach allows precise control of electrical properties through thermal parameter manipulation.
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 method effectively creates a gradient in electrical resistivity through the thickness of the carbon foam, enabling its use in advanced applications like radar absorption and electromagnetic interference shielding, with the ability to customize resistivity values based on specific requirements.
Implementation Method 1
heating the first surface of the carbon foam body at a temperature and for a time effective to decrease the electrical resistivity near the first surface
Data Source
AI summary
Electrically gradated carbon foam materials that have changing or differing electrical properties through the thickness of the carbon foam material and methods for making these electrically gradated carbon foam materials are described herein. In some embodiments, the electrically gradated carbon foam materials exhibit increasing electrical resistivity through the thickness of the carbon foam material such that the electrical resistivity near a second surface of the carbon foam is at least 2 times greater than the electrical resistivity near a first surface of the carbon foam. These electrically gradated carbon foam materials may be used as radar absorbers, as well as in electromagnetic interference (EMI) shielding schemes.