CNT String Field Emission Electron Source
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for manufacturing field emission electron sources using carbon nanotubes face challenges with controllability, mechanical connection reliability, and field emission efficiency due to the small size of individual nanotubes and the shield effect between adjacent nanotubes.
Innovation Solution
A method involving the formation of a CNT string by drawing a bundle of CNTs into a yarn, soaking it in an organic solvent, and then applying voltage to snap it into a tooth-shaped structure for attachment to a conductive base, enhancing mechanical and electrical conductivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If in-situ synthesis method is used to form CNTs on conductive base, then CNTs can be directly synthesized on the base, but the mechanical connection between CNTs and conductive base is weak and unreliable
Solution Approach 1:
The invention separates the CNT formation process from the base attachment process. Instead of synthesizing CNTs directly on the base (in-situ), the method first forms CNT arrays on a temporary substrate, then transfers them to the conductive base. This segmentation allows optimization of each step independently, ensuring strong mechanical connection at the transfer stage while maintaining ease of manufacture through standardized processes.
Solution Approach 2:
The invention introduces a temporary substrate as an intermediary carrier for the CNT arrays. This mediator allows the CNTs to be formed and handled on a stable platform before being transferred to the final conductive base. The intermediary substrate enables reliable mechanical connection through controlled transfer mechanisms while preserving the ease of CNT synthesis and positioning.
2Measurement precision
If mechanical method is used to place single CNT on conductive base, then single CNT positioning is possible, but controllability is less than desired due to tiny size
Solution Approach 1:
The invention merges multiple individual CNTs into a bundled CNT array structure. Instead of handling single CNTs which are difficult to control, the method bundles many CNTs together to form a larger, more controllable unit. This merging maintains the precision of positioning (through array structure) while dramatically improving ease of operation, as the bundled array can be manipulated and positioned much more easily than individual nanotubes.
3Ease of operation
If bundle of CNTs is used as emitter, then controllability is improved, but shield effect between adjacent CNTs reduces field emission efficiency
Solution Approach 1:
The invention applies local quality by creating a tooth-shaped structure at the tip of the CNT bundle. Instead of a uniform bundle structure, the tip is locally modified to have protruding teeth that concentrate the electric field. This local structural change at the emission tip enhances field emission efficiency by reducing the shield effect between adjacent CNTs, while the overall bundled structure maintains good controllability during positioning and attachment.
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 improves the controllability, mechanical strength, and field emission efficiency of the electron source by creating a larger-scale emitter with a firm connection and reduced shield effect, allowing precise control over the snapping location and enhanced performance.
Implementation Method 1
soaking the CNT yarn into an organic solvent, and shrinking the CNT yarn into a CNT string after the organic solvent volatilizing
Implementation Method 2
bombarding a predetermined point of the CNT string by an electron emitter, until the CNT string snapping
Data Source
AI summary
A method for manufacturing a field emission includes: providing a CNT array; drawing a bundle of CNTs from the CNT array to form a CNT yarn; soaking the CNT yarn into an organic solvent, and shrinking the CNT yarn into a CNT string after the organic solvent volatilizing; applying a voltage between two opposite ends of the CNT string; bombarding a predetermined point of the CNT string by an electron emitter, until the CNT string snapping; and attaching the snapped CNT string to a conductive base, and achieving a field emission electron source. The field emission efficiency of the field emission electron source is high.