Liquid Evaluation Device Using Capillary Channels
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Solution Overview
Problem
Existing methods for determining the accuracy of multichannel liquid handling devices are tedious, expensive, and prone to errors due to the need for sensitive balances, expensive equipment, and multiple measurements, which can introduce inaccuracies in liquid volume measurement.
Innovation Solution
A liquid evaluation device featuring a cartridge with closely spaced substrates and hydrophobic coatings forming channels, where liquid flow structures facilitate liquid flow and location within the channels for precise volume measurement, reducing the need for expensive equipment and minimizing measurement errors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a balance is used to measure liquid volume by mass conversion, then measurement precision can be achieved, but device complexity and cost increase due to requiring sensitive balances more accurate than 10 micrograms
Solution Approach 1:
The patent replaces the mechanical balance-based measurement system with an optical measurement system. Instead of using a sensitive balance to measure mass and convert to volume, the invention uses optical methods to directly measure liquid volume in capillaries, eliminating the need for expensive and complex balance equipment while maintaining measurement precision.
Solution Approach 2:
The patent introduces capillaries as an intermediary element between the liquid dispensing system and the measurement system. The capillaries serve as a mediator that allows optical measurement of liquid volume directly, avoiding the need for direct mass measurement with sensitive balances and simplifying the overall measurement system.
2Measurement precision
If multiple measurements are performed to evaluate liquid handling accuracy, then measurement precision improves, but loss of time increases due to tedious evaluation procedures
Solution Approach 1:
The patent segments the evaluation process by using multiple capillaries arranged in parallel within a single cartridge, allowing simultaneous measurement of multiple liquid volumes in one operation. This segmentation enables parallel processing of measurements, reducing total evaluation time while maintaining precision through repeated measurements across different capillaries.
Solution Approach 2:
The patent enables continuous measurement by allowing the liquid handling system to dispense liquid into the cartridge with multiple capillaries in a single continuous operation. The optical measurement system can then continuously read volumes from all capillaries without interruption, eliminating the need for separate discrete measurement steps and reducing overall evaluation time.
3Measurement precision
If expensive equipment is used for liquid evaluation, then measurement precision improves, but ease of manufacture worsens due to difficulty in obtaining and transporting specialized equipment
Solution Approach 1:
The patent employs inexpensive capillaries and cartridge components that can be easily manufactured and disposed of after a single use. Instead of requiring expensive, fragile, and difficult-to-transport measurement equipment, the invention uses simple, affordable capillary structures that can be mass-produced and discarded after one measurement cycle, significantly improving ease of manufacture and equipment acquisition.
4Device complexity
If capillary action is used to draw liquid into channels, then device complexity is reduced, but measurement precision worsens due to limitations in capillary action effectiveness for round ducts
Solution Approach 1:
The patent transitions from symmetric round ducts to asymmetric rectangular or non-circular capillary cross-sections. This asymmetry in capillary geometry enhances the effectiveness of capillary action by creating more favorable surface area to volume ratios and improved wetting characteristics, thereby maintaining simple device architecture while significantly improving measurement precision through better liquid filling and optical detection.
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
The solution provides a cost-effective and accurate method for measuring liquid volumes by utilizing passive features to manipulate liquid flow, enhancing measurement accuracy and reducing errors associated with traditional methods.
Implementation Method 1
A liquid evaluation device features a cartridge with closely spaced substrates and hydrophobic coatings forming channels, where liquid flow structures facilitate liquid flow and location within the channels
Data Source
AI summary
A liquid evaluation device including a cartridge with one or more channels formed between two closely spaced substrates is disclosed. The cartridge includes one or more liquid flow structures, each of which can be located in a deposition region for a channel, an entrance region for the channel, and/or an interior region of the channel. Each liquid flow structure is configured to facilitate liquid flow to shape and/or locate the liquid in the channel for measuring a volume of the liquid located in the channel.