Nanopore Sensors in Microfluidic Arrays via Controlled Breakdown
Solution Overview
Problem
Conventional methods for fabricating solid-state nanopores in microfluidic channels face challenges such as alignment requirements, integration issues, and handling risks due to the need for direct line-of-sight access with high-energy beams, which limits the yield and durability of nanopore sensors, especially in reduced microfluidic channel dimensions and aqueous environments.
Innovation Solution
The controlled breakdown (CBD) method induces a dielectric breakdown in a thin insulating membrane within microfluidic channels to form nanopores, allowing for in situ fabrication under biological sensing conditions, enabling integration with complex microfluidic architectures and improving device durability and applicability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If high-energy ion or electron beams are used to fabricate nanopores, then nanopores can be formed in ultrathin dielectric membranes, but direct line-of-sight access is required which complicates integration into microfluidic devices
Solution Approach 1:
The patent replaces mechanical beam-based fabrication with an electric field-based controlled breakdown method. High-energy ion or electron beams are substituted with electrical signals applied through microfluidic channels, eliminating the need for line-of-sight access and complex alignment mechanisms while maintaining nanopore fabrication capability
Solution Approach 2:
The patent introduces an intermediary electrical signal transmission mechanism through the microfluidic channel medium. Instead of direct beam access, electric fields are transmitted through the aqueous solution in the microfluidic channels to induce dielectric breakdown and nanopore formation, serving as a mediator between the control system and the membrane
2Manufacturing precision
If strict alignment requirements are imposed during nanopore fabrication, then nanopores can be formed with precise positioning, but the yield of functional devices is reduced
Solution Approach 1:
The patent employs self-alignment mechanisms where the electric field naturally concentrates at the membrane location within the microfluidic channel. The system uses the inherent geometry of the microfluidic channel and membrane interface to automatically position nanopores without requiring external alignment procedures, thereby improving yield while maintaining precision
Solution Approach 2:
The patent performs preliminary structuring of the microfluidic channel geometry and membrane positioning before nanopore fabrication. The microfluidic channel network is pre-designed to guide electric field lines to specific membrane regions, establishing precise nanopore locations through the preliminary structural configuration rather than during the fabrication process itself
3Ease of manufacture
If nanopores are fabricated before integration into microfluidic devices, then beam access is enabled, but handling risks and wetting issues arise when transitioning to aqueous solutions
Solution Approach 1:
The patent performs preliminary integration of the membrane into the microfluidic device structure before nanopore fabrication. The membrane is pre-mounted within the sealed microfluidic channel network, creating a protected environment that eliminates handling risks and prevents wetting issues during subsequent nanopore formation and operation in aqueous solutions
Solution Approach 2:
The patent provides beforehand protection by sealing the membrane within the microfluidic device structure prior to nanopore fabrication. This preliminary encapsulation cushions the membrane against mechanical damage and uncontrolled environmental exposure, ensuring reliability when the device transitions to aqueous solution operation
4Object-affected harmful factors
If microfluidic channel dimensions are reduced to minimize electrical noise, then noise is reduced, but alignment and integration challenges increase
Solution Approach 1:
The patent replaces mechanical alignment systems with electric field-based positioning. In reduced-dimension microfluidic channels, the electric field naturally concentrates at the membrane location, enabling precise nanopore formation without complex mechanical alignment mechanisms, thus reducing noise while maintaining integration simplicity
Solution Approach 2:
The patent changes the fabrication approach from mechanical beam-based methods to electric field-based controlled breakdown. This parameter change enables effective nanopore fabrication in highly confined microfluidic channels where mechanical alignment would be prohibitively complex, allowing noise reduction through miniaturization without sacrificing integrability
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
CBD facilitates the reliable formation of nanopores with precise control over size and location, reducing noise and enhancing the integration of nanopore sensors within microfluidic devices, expanding their range of applications and improving the robustness of lab-on-a-chip devices.
Implementation Method 1
a dielectric breakdown event is induced in the supporting intact insulating membrane resulting in the formation of a single nanopore
Implementation Method 2
charged biomolecules such as DNA and proteins that are electrophoretically driven through the nanopore
Data Source
Figure 1
Figure 2A~2B
Figure 3A~3C
AI summary
An apparatus for fabricating one or more nanopores in a membrane is disclosed. Nanopore arrays are fabricated by controlled breakdown in solid-state membranes integrated within polydimethylsiloxane (PDMS) microfluidic devices. This technique enables the scalable production of independently addressable nanopores. By confining the electric field within the microfluidic architecture, nanopore fabrication is precisely localized and electrical noise is significantly reduced during sensing. (Fig. 1)