Carbon Nanotube Field Emitter Uniform Spacing
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Solution Overview
Problem
Existing methods for producing carbon nanotube field emitters face challenges in achieving high field emission efficiency and are difficult to mass produce, with snapped CNT strings being hard to manipulate and maintain uniform spacing, affecting emission efficiency.
Innovation Solution
A method involving the formation of a carbon nanotube array on a substrate, drawing a film, cutting it into sub-films, treating them into yarns, and fixing them on a conductive base using a laser to create uniform carbon nanotube field emitters with a flat electron emitting end, optimizing spacing and emission properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If snapped CNT strings are used to make field emitters, then field emission can be achieved, but the snapped CNT strings are difficult to manipulate and maintain uniform spacing
Solution Approach 1:
The patent divides the CNT array into multiple separate CNT strings by applying voltage to snap them at specific points. This segmentation allows each string to be independently positioned and manipulated on the conductive base, improving both field emission efficiency and ease of operation compared to handling a single continuous array.
Solution Approach 2:
The patent replaces manual mechanical manipulation of snapped CNT strings with an electric field-based positioning system. By applying voltage between the CNT array and conductive base, the CNT strings are automatically attracted and positioned at uniform intervals, eliminating the need for difficult manual manipulation while maintaining uniform spacing.
2Reliability
If snapped CNT strings are used, then field emission is achieved, but mass production in large quantity is difficult
Solution Approach 1:
The patent performs preliminary actions by first growing a complete CNT array on a conductive base, then applying voltage to snap multiple strings simultaneously at predetermined locations. This batch processing approach enables mass production of field emitters in large quantities while maintaining uniform spacing and high field emission efficiency, rather than producing individual strings one at a time.
Solution Approach 2:
The patent employs a self-organizing mechanism where applying voltage causes CNT strings to automatically snap and position themselves at uniform intervals on the conductive base. This self-positioning behavior eliminates the need for complex manual alignment procedures, enabling scalable mass production while maintaining consistent field emission performance across large numbers of emitters.
3Ease of operation
If uniform spacing between adjacent snapped CNT strings is difficult to achieve, then field emission efficiency is affected
Solution Approach 1:
The patent replaces mechanical alignment methods with an electric field-based positioning system. By applying voltage between the CNT array and conductive base, the CNT strings are automatically attracted and positioned at uniform intervals through electrostatic forces, achieving precise uniform spacing that directly improves field emission efficiency.
Solution Approach 2:
The patent changes the physical state and positioning parameters of CNT strings by applying voltage, which causes them to snap and reposition. This parameter change (from static to voltage-controlled dynamic positioning) enables precise control over spacing uniformity, directly impacting field emission efficiency by ensuring optimal distances between adjacent emitters.
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 results in carbon nanotube field emitters with improved field emission efficiency, ease of operation, and scalability for mass production, with uniform spacing reducing shielding effects and enhancing emission properties.
Implementation Method 1
cutting them into sub-films, treating them into yarns, and fixing them on a conductive base with a laser
Data Source
AI summary
A method for making carbon nanotube field emitter includes providing a carbon nanotube array formed on a surface of a substrate. A plurality of carbon nanotubes of the carbon nanotube array is selected and pulled out a carbon nanotube film by a drawing tool, wherein the carbon nanotube film includes a plurality of carbon nanotubes oriented along a fixed direction. The carbon nanotube film is cut to a plurality of uniform carbon nanotube sub-films along the fixed direction. The plurality of carbon nanotube sub-films is treated to a plurality of carbon nanotube yarns. The plurality of carbon nanotube yarns is fixed on a surface of a conductive base, and cutting off the plurality of carbon nanotube yarns by a laser beam, to form a carbon nanotube field emitter.