Microfluidic Device Hygroscopic Fluid Volume Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Microfluidic devices face challenges in maintaining uniform liquid volume due to evaporation, which can be exacerbated by environmental factors like temperature, pressure, and humidity, leading to variations in liquid volume and interfacial tension issues.
Innovation Solution
A microfluidic device design incorporating a chamber with a hygroscopic material dissolved in a first fluid and a second immiscible fluid, where an electrical field is applied to control the interface between the fluids, maintaining a volume variation of 5% or less at equilibrium density, using materials like lithium chloride or lithium bromide, and employing an electrode configuration to vary the lens surface curvature or aperture size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a liquid with low vapor pressure is used to reduce evaporation, then volume stability is improved, but interfacial tension is reduced and viscous friction is increased
Solution Approach 1:
The patent changes the chemical composition parameters of the liquid by dissolving hygroscopic materials (such as lithium chloride or lithium bromide) in the liquid to adjust its vapor pressure and maintain volume stability while managing interfacial tension and viscous friction effects
Solution Approach 2:
The patent uses composite liquid systems consisting of multiple components including the base liquid and dissolved hygroscopic materials to achieve the desired balance between vapor pressure reduction and acceptable interfacial tension and viscosity characteristics
2Volume of moving object
If the amount of aqueous solution is reduced to picoliter level, then device miniaturization is improved, but evaporation rate is increased
Solution Approach 1:
The patent changes the physical and chemical parameters of the liquid by adding hygroscopic materials that actively absorb moisture from the air, compensating for evaporative losses and maintaining volume stability even at picoliter scales
Solution Approach 2:
The hygroscopic materials in the liquid system automatically absorb moisture from the environment to compensate for evaporation, creating a self-regulating system that maintains volume without requiring external control mechanisms
3Reliability
If environmental factors (temperature, pressure, humidity) are controlled to prevent evaporation, then volume stability is improved, but system complexity is increased
Solution Approach 1:
The system uses the inherent hygroscopic properties of the dissolved materials to automatically regulate moisture content and compensate for evaporation without requiring external environmental control systems
Solution Approach 2:
The patent extracts the environmental control function from the system by using the liquid's own chemical properties to handle evaporation compensation, eliminating the need for separate temperature, pressure, or humidity control mechanisms
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 effectively stabilizes the volume of the fluid within microfluidic devices, minimizing evaporation effects and maintaining device performance by achieving equilibrium density, thus ensuring consistent operation and easy manufacturing.
Implementation Method 1
a first fluid that is disposed in the chamber and in which a hygroscopic material is dissolved
Implementation Method 2
an electrode portion that is provided in the chamber and is configured to form an electrical field in the chamber when a voltage is applied to the electrode portion, wherein an interface between the first and second fluids is varied according to the electrical field
Data Source
AI summary
A microfluidic device and a method of controlling a fluid included in the microfluidic device. The microfluidic device includes: a chamber; a first fluid that is disposed in the chamber and in which a hygroscopic material is dissolved; a second fluid that is disposed in the chamber and is immiscible with the first fluid; and an electrode portion provide in the chamber and is configured to form an electrical field in the chamber when a voltage is applied to the electrode portion, wherein an interface between the first and second fluids is varied according to the electrical field.