Nanofibrillar Architecture via Mechanical Tension and Crystallization
Solution Overview
Problem
Current methods for fabricating fibrous structures, such as electrospinning and chemical self-assembly, face limitations in speed, throughput, and control over fiber orientation and resolution, which restrict the formation of complex nanofibrillar architectures with tunable mechanical properties.
Innovation Solution
A method involving the formation of a fibrillar or fibrous material solution, infiltration into a deformable mold, induction of gelation, and application of mechanical tension to create nanofibrillar structures, followed by re-entrapping the structure via crystallization, allowing for the creation of large-scale, aligned nanofibrillar architectures with controlled birefringence and mechanical properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If electrospinning is used to fabricate fibrous structures, then fiber formation is achieved, but speed and throughput are limited
Solution Approach 1:
The patent replaces electrospinning's electrostatic field-based fiber formation with a mechanical tension-based approach. A gel precursor is infiltrated into a mold and then mechanically stretched to align nanofibrils, substituting electrical field control with direct mechanical deformation to achieve high-speed fiber formation while maintaining control over fiber orientation and architecture.
Solution Approach 2:
The invention changes the state parameters of the material during fabrication. The gel precursor transitions from a soft, infiltratable state to a stretched, aligned nanofibrillar structure through controlled mechanical tension. This parameter change enables rapid fabrication while preserving the ability to control fiber orientation and architectural features.
2Manufacturing precision
If chemical self-assembly is used to form fibrous structures, then fiber organization is achieved, but control over fiber orientation and resolution is limited
Solution Approach 1:
The patent performs preliminary organization of nanofibrils within a mold before final structure formation. The gel precursor is infiltrated into a pre-designed mold that defines the desired architectural features, and then mechanically stretched to align nanofibrils along tension axes. This preliminary organization enables precise control over fiber orientation and resolution without requiring complex real-time process control.
Solution Approach 2:
The invention uses a gel precursor as an intermediary medium that facilitates controlled nanofibril organization. The gel acts as a carrier that can be infiltrated into molds and then mechanically deformed, serving as a mediator between the desired final architecture and the actual nanofibril formation process, thereby simplifying process control while achieving high manufacturing precision.
3Manufacturing precision
If mechanical tension is applied to create nanofibrillar structures, then fiber alignment and birefringence are improved, but structural re-entrapping is required
Solution Approach 1:
The patent utilizes phase transitions to achieve structural re-entrapping. After mechanical tension aligns the nanofibrils and creates the desired architecture, the stretched gel structure is allowed to undergo phase transition (sol-to-gel transition or crystallization) that locks in the aligned nanofibrillar configuration. This phase transition enables the structure to re-entrain itself without requiring additional complex processing steps.
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 enables the production of nanofibrillar architectures with tunable mechanical properties and controlled alignment, achieving high birefringence and strain-stiffening effects, suitable for applications in biotechnology and energy.
Implementation Method 1
induction of gelation
Implementation Method 2
application of mechanical tension
Implementation Method 3
controlled birefringence and mechanical properties
Implementation Method 4
re-entrapping the structure via crystallization
Data Source
AI summary
This present disclosure provides methods for utilizing such forces in when generating nanofibrillar constructs with engineered morphology from the nano- to macro-scales. Using for example, a biopolymer silk fibroin as a base material, patterns an intermediate hydrogel were generated within a deformable mold. Subsequently, mechanical tension was introduced via either hydrogel contraction or mold deformation, and finally a material is reentrapped in this transformed shape via beta-sheet crystallization and critical point drying. Topdown engineered anchorages, cables, and shapes act in concert to mediate precision changes in nanofiber alignment/orientation and a macroscale form of provided nanofibrillar structure. An ability of this technique to engineer large gradients of nano- and micro-scale order, manipulate mechanical properties (such as plasticity and thermal transport), and the in-situ generation of 2D and 3D, multi-tiered and doped, nanofibrillar constructs was demonstrated.