Liquid Drop Dispenser With Segmented Electrodes
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Solution Overview
Problem
Existing liquid dispensing devices using electrostatic forces for drop formation in microfluidics face reliability issues due to pressure changes in the liquid reservoir, leading to inconsistent drop volumes.
Innovation Solution
A contained liquid dispensing device with a first and second substrate, featuring a transfer electrode, drop-forming electrodes, and reservoir electrodes, where the pressure in the liquid reservoir is independent of the well pressure, allowing for consistent drop formation and ejection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If a liquid reservoir is used for drop formation in microfluidics, then liquid supply is enabled, but pressure changes in the reservoir lead to inconsistent drop volumes
Solution Approach 1:
The device is segmented into distinct functional zones: a liquid reservoir, an electrostatic actuation zone with patterned electrodes, and a drop ejection zone. This spatial segmentation allows the reservoir to supply liquid while the electrostatic field precisely controls drop formation, isolating the drop volume from reservoir pressure variations.
Solution Approach 2:
Patterned electrodes serve as an intermediary between the liquid reservoir and the drop ejection process. These electrodes generate localized electrostatic fields that manipulate liquid at the electrode-liquid interface, enabling precise drop volume control independent of reservoir pressure. The electrodes mediate the transformation from bulk liquid supply to controlled drop formation.
2Manufacturing precision
If electrostatic forces are used for drop manipulation, then precise control is achieved, but the system complexity increases
Solution Approach 1:
The electrode system implements local quality by creating spatially varying electrostatic fields only where needed for drop manipulation. Patterned electrodes are positioned specifically at the liquid interface, activating electrostatic forces locally rather than throughout the entire device. This localized approach achieves precise drop control while minimizing overall system complexity.
Solution Approach 2:
The system uses dynamic control of electrode potentials to manipulate drops. By sequentially activating and deactivating specific electrodes, the system dynamically controls drop formation, movement, and ejection. This temporal dynamics allows a relatively simple electrode pattern to achieve complex drop manipulation tasks.
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
Enables the formation of drops with consistent volume, independent of the well pressure, improving the reproducibility and precision of liquid dispensing in microfluidic applications.
Implementation Method 1
The invention concerns a device and a process for the formation of drops or of small volumes of liquid, from a liquid reservoir, using electrostatic forces.
Implementation Method 2
One of the most frequently used methods of fluid movement or manipulation is based upon the principle of electro-wetting on a dielectric
Implementation Method 3
the dielectric layer 6 and the hydrophobic layer 8 between this activated electrode and the drop, polarised by the counter-electrode 10, act as a capacitance, and the electrostatic charge effects induce the movement of the drop
Implementation Method 4
the dielectric layer 6 and the hydrophobic layer 8 between this activated electrode and the drop, polarised by the counter-electrode 10, act as a capacitance
Implementation Method 5
The forces of electrostatic origin are superimposed on the wetting forces, which causes spreading of the drop on the surface
Implementation Method 6
the wetting forces, which causes spreading of the drop on the surface
Data Source
AI summary
A liquid dispensing device includes first and second substrates, with the first substrate including an opening for introduction of a fluid, and the second substrate including a multiplicity of electrodes. The device includes a transfer electrode, located at least partially opposite to the opening, at least two drop-forming electrodes, and a reservoir electrode, located between the transfer electrode and the drop-forming electrodes, and with an area that is at least equal to three times the area of each drop-forming electrode.