Porous Polymer Etching for High Aspect Ratio Microchannels
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Solution Overview
Problem
Current methods for producing porous materials with microscale features are limited in scalability, throughput, and complexity, particularly in achieving high aspect ratios and porosity, as existing technologies like machining, extrusion, and three-dimensional printing face challenges in producing materials with high percentages of porosity and complex shapes.
Innovation Solution
The technology involves embossing polymer compositions to create porous materials with microscale and nanoscale features, utilizing roll-to-roll processing and porogen-based methods to produce materials with high open lumen volume, high surface-to-volume ratio, and high permeability, allowing for the creation of materials with aligned microchannel features and hierarchical porosity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional machining methods are used to produce microscale features, then features can be produced in a variety of materials and over a range of scales, but they cannot produce three-dimensional high aspect ratios in the microscale range and do not work well on many polymeric materials
Solution Approach 1:
The patent replaces conventional mechanical machining methods with a chemical etching process using fluorocarbon plasma. This substitution enables the production of high aspect ratio microscale features (e.g., 10:1 or higher) in polymeric materials that are difficult or impossible to machine conventionally, while maintaining precise dimensional control through controlled chemical reactions rather than mechanical contact.
Solution Approach 2:
The patent utilizes controlled changes in plasma process parameters (power, pressure, gas flow rates, treatment time) to achieve selective etching of polymeric materials. By adjusting these parameters, the process can produce high aspect ratio features with controlled morphology and dimensions, adapting to different polymer types and desired feature geometries without requiring mechanical tooling changes.
2Length of moving object
If extrusion technologies are used to produce high aspect ratios, then high aspect ratios can be achieved in a variety of shapes, but materials cannot have high percentages of porosity (e.g., greater than approximately 30 vol %) while maintaining microscale features
Solution Approach 1:
The patent employs a two-stage process that segments the feature creation and porosity introduction steps. First, high aspect ratio microscale features are etched into the polymer matrix using fluorocarbon plasma. Second, porogens (such as salt particles or bubbles) are introduced and the material is reprocessed to create high porosity (greater than 30 vol %) while preserving the previously formed microscale features, achieving both high aspect ratio and high porosity simultaneously.
Solution Approach 2:
The patent performs preliminary etching of high aspect ratio microscale features into the polymer material before introducing porogens and reprocessing. This preliminary action ensures that the microscale features are established and protected during the subsequent porosity creation process, allowing the final material to maintain both high aspect ratio features and high porosity (greater than 30 vol %).
3Manufacturing precision
If three-dimensional printing technologies are used, then microscale production is increasingly transitioning, but UV-curing technologies are hindered by the 'bleed' of features, especially at small scales, limiting feature size and aspect ratio
Solution Approach 1:
The patent replaces UV-curing three-dimensional printing with a fluorocarbon plasma etching process for creating microscale features. This substitution eliminates the feature bleed problem inherent in UV-curing technologies, as the plasma process provides sharp, well-defined feature boundaries through controlled chemical reactions rather than photopolymerization, enabling precise microscale features with high aspect ratios (10:1 or higher).
4Length of moving object
If dip-coating methods are used to produce microscale features from porous polymers at high aspect ratios, then microscale features can be produced at high aspect ratios, but only simple shapes can be produced in batch processes with low throughput
Solution Approach 1:
The fluorocarbon plasma etching process serves multiple functions: it can produce high aspect ratio microscale features, create complex three-dimensional shapes, and process materials continuously at high throughput. The process is universal in its ability to etch various polymeric materials with different properties, replacing the limited dip-coating method that could only produce simple shapes in batch mode.
Solution Approach 2:
The patent implements continuous fluorocarbon plasma etching processing that can operate in continuous or high-volume batch mode, dramatically increasing throughput compared to traditional dip-coating batch processes. The continuous plasma process maintains consistent etching quality while processing large quantities of material, enabling high-volume production of complex-shaped components with high aspect ratio microscale features.
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 materials with reproducible, homogeneous microscale features and high interconnecting porosity, overcoming the limitations of existing methods by achieving scalable batch sizes and complex shapes with enhanced fluid flow and mechanical properties.
Implementation Method 1
A method for producing a porous material with microscale features comprises providing a polymeric material and treating the polymeric material with fluorocarbon plasma to etch the polymeric material and produce the porous material with microscale features
Implementation Method 2
In some embodiments, the technology comprises use of a polymer composition (e.g., polycaprolactone (PCL), poly(lactic-co-glycolic acid) (PLGA), etc.). In some embodiments, materials produced according to the technology provided herein comprise a first composition and a second composition. In some embodiments, a first composition comprises (e.g., encloses) a second composition that is a porogen. In some embodiments, a first composition comprises (e.g., encloses) a second composition and the second composition is subsequently removed to provide a void space in the first composition
Data Source
AI summary
Provided herein is technology relating to materials having microscale and/or nanoscale features and particularly, but not exclusively, to porous materials comprising microscale features, methods for producing porous materials comprising microscale features, drug delivery vehicles, and related kits, systems, and uses.