Digital Microfluidic Droplet Chip Electrode Density
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Solution Overview
Problem
Conventional digital microfluidic systems face limitations in the number of droplet actuation electrodes that can be arrayed, have small transistors not optimal for typical droplet sizes, and complex, expensive fabrication processes, making them unsuitable for inexpensive, disposable, or limited-use analytical assay devices.
Innovation Solution
The system divides digital microfluidic components into a droplet chip with an array of droplet actuation electrodes and a control chip with transistors, allowing for a reusable control chip and a disposable droplet chip, enabling increased throughput and density of electrodes while maintaining cost-effectiveness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a two-dimensional planar substrate with individually addressable droplet actuation electrodes is used, then the fabrication is simpler, but the number of droplet actuation electrodes that can be arrayed is limited
Solution Approach 1:
The patent transitions from a two-dimensional planar substrate to a three-dimensional substrate structure, allowing electrodes to be arranged in multiple layers and planes. This vertical stacking enables significantly more electrodes to be arrayed within the same footprint area, resolving the limitation on electrode quantity while maintaining fabrication feasibility through extended dimensional space.
Solution Approach 2:
The substrate is divided into multiple independent layers or planes, with electrode arrays distributed across different levels. This segmentation allows each layer to be fabricated and addressed independently, enabling a high density of electrodes without requiring all connections to coexist on a single two-dimensional plane, thus increasing the total number of addressable electrodes.
2Quantity of substance
If three-dimensional processes such as CMOS and TFT are used to increase the number of electrodes, then the throughput and quantity of achievable electrodes increase, but the fabrication processes become considerably more complex and expensive
Solution Approach 1:
The device is segmented into a reusable control chip containing the complex transistor arrays and a disposable droplet chip containing the electrode arrays. This segmentation allows the complex three-dimensional transistor fabrication (CMOS/TFT) to be confined to a single control chip that can be manufactured once and reused, while the droplet chip with simpler electrode structures can be fabricated using less complex processes and disposed of after use, thereby reducing overall system complexity and cost.
Solution Approach 2:
The control chip serves as a universal interface that can control multiple different droplet chips. The complex transistor arrays and control logic are implemented once in the reusable control chip, which then provides multi-functional control capability for various assay configurations. This universality amortizes the complexity and cost of three-dimensional fabrication across multiple uses and applications.
3Quantity of substance
If three-dimensional processes such as CMOS and TFT are used, then the quantity of achievable electrodes increases, but the small size of transistors is not optimal for typical droplet sizes used in digital microfluidic devices
Solution Approach 1:
The system segments the control functions into a separate control chip where transistor size is optimized for the specific application. The control chip can use appropriately sized transistors for typical droplet sizes, while the droplet chip contains the electrode arrays that directly interact with the droplets. This segmentation allows independent optimization of transistor dimensions for droplet manipulation without compromising electrode density or droplet interaction effectiveness.
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 provides a highly programmable, low-cost, disposable droplet chip with a reusable control chip, enabling high-density electrode arrays and efficient droplet manipulation, suitable for various microfluidic applications.
Implementation Method 1
electro-wetting-on-dielectric is a mechanism that may be used to dispense and manipulate droplets and/or bubbles. The electro-wetting-on-dielectric (EWOD) and dielectrophoresis (DEP) are mechanisms that exploit electromechanical forces to control the droplets and/or bubbles.
Implementation Method 2
The electro-wetting-on-dielectric (EWOD) and dielectrophoresis (DEP) are mechanisms that exploit electromechanical forces to control the droplets and/or bubbles.
Data Source
AI summary
The present disclosure relates to digital microfluidic systems. Particularly, aspects are directed to a digital microfluidic system that includes a droplet chip having a substrate, a plurality of electrodes and corresponding plurality of conducting vias or embedded conductive posts formed in the substrate, and a dielectric layer formed over the plurality of electrodes; and a control chip having a substrate, a plurality of transistors and corresponding wiring layers formed in the substrate, and a plurality of contacts formed over the plurality of transistors. Each of the plurality of contacts is electrically connected to a corresponding transistor of the plurality of transistors, and one or more of the plurality of contacts is removably connected to one or more of the plurality of conducting vias or embedded conductive posts such that one or more of the plurality of transistors are electrically connected to one or more of the plurality of electrodes.