Block Copolymer Filter Membrane for Uniform Nanoscale Pores
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current filter technologies face challenges in producing high-quality, highly selective, and cost-effective filters with small, controllable pore sizes suitable for integration with electronic circuits, particularly CMOS circuits, while also achieving high throughput and efficiency in applications like water purification and blood filtration.
Innovation Solution
A method involving a block copolymer layer that self-assembles into domains, which are selectively removed to create a mask for etching pores in a substrate, allowing for the formation of filters with small, uniform, and highly controllable pore sizes, integrated with semiconductor substrates and compatible with CMOS processing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional filter production methods are used, then manufacturing simplicity is maintained, but pore size control precision and filter selectivity deteriorate
Solution Approach 1:
The block copolymer layer self-assembles into periodic domains without external intervention, automatically creating a self-organized mask pattern that defines pore positions and sizes. This self-service mechanism eliminates the need for complex lithographic patterning processes while achieving precise nanoscale pore control.
Solution Approach 2:
The pore size and distribution are controlled by changing parameters of the block copolymer system, including copolymer composition ratios, molecular weights, and annealing temperatures. These parameter changes directly tune the self-assembled domain structures, enabling precise control of pore characteristics without complex manufacturing steps.
2Manufacturing precision
If pore size is reduced to increase selectivity, then filtration selectivity improves, but throughput decreases
Solution Approach 1:
The filter membrane is segmented into numerous small pores distributed across a large area, rather than having few large pores. The block copolymer self-assembly creates high-density arrays of uniform nanoscale pores that provide both fine selectivity and high total throughput by distributing flow across many parallel pathways.
Solution Approach 2:
The solution transitions from controlling pore size alone to controlling both pore size and pore density in two dimensions. The self-assembled block copolymer domains create two-dimensional arrays of pores where size and density are simultaneously optimized, achieving high selectivity through small pore size while maintaining high throughput through increased pore density.
3Manufacturing precision
If advanced self-assembly methods are used to achieve small pore sizes, then pore size control improves, but manufacturing cost increases
Solution Approach 1:
The block copolymer system performs self-assembly through spontaneous micellization and domain formation driven by thermodynamic forces, eliminating the need for expensive equipment such as electron beam lithography or focused ion beam systems. This self-service approach achieves nanoscale precision using simple, low-cost processing steps.
Solution Approach 2:
The block copolymer layer serves as a temporary, disposable mask that is deposited, self-assembled, and then removed after transferring the pore pattern to the membrane. This disposable mask approach avoids the need for expensive, reusable lithographic equipment and complex alignment systems, significantly reducing manufacturing costs.
4Manufacturing precision
If filters are designed for high selectivity with small pores, then filtration quality improves, but integration with electronic circuits becomes difficult
Solution Approach 1:
The block copolymer self-assembly method is a universal patterning technique that can be applied to various substrate materials including silicon, glass, and polymer membranes. The process uses standard thin film deposition and thermal annealing techniques compatible with CMOS fabrication, enabling the same method to produce filters for different applications and integrate with electronic circuits.
Solution Approach 2:
The mechanical lithographic patterning processes are replaced with a chemical self-assembly mechanism that naturally forms periodic patterns through block copolymer phase separation. This substitution eliminates the need for complex mechanical alignment and patterning equipment, enabling seamless integration with semiconductor manufacturing processes.
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 filters with efficient and selective filtration capabilities, high throughput, and a compact design, while being cost-effective and compatible with CMOS fabrication, suitable for various applications including water and blood filtration.
Implementation Method 1
converting the block copolymer layer to a mask by selectively removing domains of the block copolymer layer
Implementation Method 2
the polymer blocks may form a linear chain. The BCPs may e.g. be diblock copolymers (di-BCPs), where each linear chain comprises two blocks, A and B. However, any type of BCP may be used, e.g. triblock copolymers (tri-BCPs).
Implementation Method 3
fluid passing through the channel and the pores is filtered by the pores
Data Source
AI summary
A method for producing a filter, the method comprisingproviding a first layer above a substrate;providing a block copolymer layer above the first layer;converting the block copolymer layer to a mask by selectively removing domains of the block copolymer layer;etching pores through the first layer in regions exposed by the mask; andforming a channel through the substrate, the channel being configured to provide fluid communication between a first and a second end of the channel, the first end of the channel being directly below the etched pores of the first layer,whereby fluid passing through the channel and the pores is filtered by the pores, when the filter is in use.