Densifying a nanofiber sheet using heat and force
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for densifying nanofiber sheets, such as using solvents, limit the alignment and density of nanofibers due to entanglements and dimensional shrinkage, making it difficult to produce commercially viable products with enhanced mechanical and electrical properties.
Innovation Solution
Applying a combination of heat and force with both tensile and compressive components to nanofiber sheets, either simultaneously or sequentially, to align and densify the nanofibers without the use of solvents, allowing for the introduction of additional materials like nanoparticles or polymers through solvent vapor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If solvent densification is used, then nanofiber sheets can be densified, but nanofiber alignment and density are limited due to entanglements and dimensional shrinkage
Solution Approach 1:
The patent replaces the chemical solvent-based densification system with a mechanical system applying controlled tensile and compressive forces. This mechanical approach directly manipulates nanofiber positioning and alignment without relying on solvent-mediated processes, thereby achieving superior alignment precision while increasing density.
Solution Approach 2:
The patent changes the physical parameters of the nanofiber sheet by applying controlled mechanical forces (tensile and compressive components) and heat. This alters the mechanical state of the nanofibers, enabling them to overcome entanglements and achieve higher density and alignment without the limitations of solvent-based methods.
2Quantity of substance
If solvent densification is used, then nanofiber sheets can be densified, but dimensional shrinkage occurs making commercial product fabrication difficult
Solution Approach 1:
The patent replaces solvent-based densification with a controlled mechanical forcing system that applies tensile and compressive forces. This mechanical approach provides precise control over dimensional changes, preventing uncontrolled shrinkage while achieving densification, thereby facilitating commercial product fabrication.
3Length of moving object
If multiple precursor nanofiber sheets are merged, then longer and thicker sheets can be produced, but uniform composition and structure are difficult to achieve
Solution Approach 1:
The patent merges multiple precursor nanofiber sheets under controlled mechanical forcing and heat treatment. The applied forces and heat ensure that the merging process creates a uniform composition and structure throughout the combined sheet, eliminating boundaries and achieving homogeneity across the entire merged structure.
Solution Approach 2:
The patent applies controlled changes in mechanical parameters (tensile and compressive forces) and thermal parameters during the merging process. These parameter changes ensure uniform densification and structural homogeneity across multiple precursor sheets, achieving consistent composition and structure in the final merged product.
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 method results in nanofiber sheets with improved mechanical and electrical properties, including increased tensile strength and conductivity, and the ability to produce longer, thicker, denser sheets and yarns with uniform composition and structure from multiple precursor sheets.
Implementation Method 1
providing, to the at least one nanofiber sheet, heat and a force having a tensile component and a compressive component
Implementation Method 2
providing, to the at least one nanofiber sheet, heat and a force having a tensile component and a compressive component
Data Source
AI summary
Methods and systems are described for continuously densifying at least one nanofiber sheet using heat and an applied force that can include both compressive and tensile components. Nanofiber sheets densified using these techniques have a more uniform and more highly aligned microstructure than nanofiber sheets densified using a solvent alone. As a result, the nanofiber sheets of the present disclosure have, for example, higher tensile strength and better electrical conductivity than nanofiber sheets densified using other techniques.