Microfluidic Device Resonating Passage Coriolis Sensing
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Solution Overview
Problem
Existing microfluidic devices face challenges in miniaturization and density sensitivity, particularly in analyzing small fluid quantities, due to their size and structural material requirements.
Innovation Solution
A microfluidic device with a compact micromachined freestanding member that uses wafer bonding and silicon etching techniques to create a resonating fluid passage with multiple channels, allowing for Coriolis force-based property sensing, including mass flow and density, while minimizing structural material and enhancing miniaturization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional microfluidic device structures are used, then the device can perform fluid analysis, but the device size and structural material requirements prevent further miniaturization and reduce density sensitivity
Solution Approach 1:
The device structure is segmented into a substrate and a separate freestanding member that is micromachined and then bonded to the substrate. This segmentation allows the sensing element to be miniaturized independently while maintaining its structural integrity and sensing capabilities, thereby improving density sensitivity without proportionally increasing overall device volume.
Solution Approach 2:
The invention transitions from planar integration to three-dimensional stacking by creating a freestanding member that is bonded to the substrate at a reduced height. This dimensional change enables the sensing structure to occupy less lateral space while maintaining sufficient structural material for density sensing, effectively decoupling device volume from sensing precision requirements.
2Volume of moving object
If conventional microfluidic device structures are used, then the device can perform fluid analysis, but the device size and structural material requirements prevent further miniaturization
Solution Approach 1:
By separating the device into a substrate and a freestanding member, each component can be optimized independently. The freestanding member can be miniaturized with minimal structural material while the substrate provides overall support, allowing device volume reduction without compromising the strength required for structural integrity.
Solution Approach 2:
The freestanding member is fabricated as a thin, micromachined structure with minimal material usage. This thin-film approach reduces the device volume significantly while the careful design of the freestanding member's geometry ensures it maintains sufficient structural strength for its sensing function.
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 device achieves improved miniaturization and increased density sensitivity, enabling precise analysis of small fluid quantities with reduced structural material, and effectively detects fluid properties using Coriolis force principles.
Implementation Method 1
the freestanding portion 16 can be vibrated at or near resonance to ascertain certain properties of the fluid
Implementation Method 2
With a fluid entering the device 10 through an inlet port 26 and flowing through an internal passage 20 within the tube 14, the freestanding portion 16 can be vibrated at or near resonance to ascertain certain properties of the fluid, such as flow rate and density, using Coriolis force principles
Data Source
AI summary
A microfluidic device a micromachined freestanding member adapted to sense one or more properties of a fluid flowing through the freestanding member. The freestanding member is supported by a substrate and spaced apart and separated from the substrate to enable the freestanding member to move relative to the substrate under the influence of a vibration-inducing element. Movement of the freestanding member relative to the substrate is then sensed by a sensing element. The freestanding member has an inlet, an outlet, an internal passage that fluidically couples the inlet and outlet, and a wall that defines and separates first and second passage portions of the internal passage that are arranged in fluidic series so that a fluid flowing through the internal passage flows through the first and second passage portions in opposite directions.