Microfluidic Mask Encoding for Particle Positioning
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Solution Overview
Problem
Current microfluidic devices face limitations in efficiently detecting and positioning particles, particularly in the out-of-plane direction, due to low throughput in sheath focusing methods and the complexity of achieving high throughput in sheathless designs, which is essential for applications involving large volumes of samples like whole blood.
Innovation Solution
A microfluidic device with a substrate and a microfluidic channel that includes a pattern of openings with varying dimensions, allowing for optical detection of particle positions through encoded waveforms generated by scattered light, enabling accurate determination of particle positions and velocities without the need for external signals or complex designs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If sheath focusing is used to position particles in microchannels, then particle positioning is achieved, but throughput is reduced
Solution Approach 1:
The patent removes the sheath flow component from the system entirely, transitioning from sheath focusing to sheathless inertial focusing. This extraction of the sheath flow enables high throughput by eliminating the bottleneck of confined sample flow while maintaining particle positioning through inertial forces alone
Solution Approach 2:
The patent replaces the mechanical/sheath-based positioning system with an inertial focusing mechanism. By utilizing inertial forces generated by the microchannel geometry and flow dynamics, particles are positioned without requiring sheath flows, thereby achieving both high throughput and positioning accuracy
2Productivity
If sheathless design is used to increase throughput, then throughput is improved, but particle confinement in out-of-plane direction becomes complex
Solution Approach 1:
The patent employs self-service inertial focusing where the microchannel geometry itself generates the necessary inertial forces to confine and position particles. The channel dimensions and flow conditions are designed to automatically produce the required focusing effects without additional components or complex control mechanisms
Solution Approach 2:
The patent utilizes parameter changes in flow rate and channel geometry to control particle positioning. By adjusting Reynolds number and channel dimensions, the inertial forces are optimized to achieve particle confinement in the out-of-plane direction without requiring complex additional structures
3Ease of manufacture
If inertial focusing is used for particle positioning, then device fabrication is simplified, but particle position detection precision is reduced
Solution Approach 1:
The patent introduces an optical intermediary system consisting of masks and cameras to detect particle positions. The masks are placed at specific locations in the microchannel to create optical patterns that encode particle position information, which is then captured by cameras for precise measurement without interfering with the inertial focusing mechanism
Solution Approach 2:
The patent utilizes optical pattern changes and light intensity variations as particles pass through masked regions. The masks create distinct optical signatures (patterns of light and shadow) that change as particles move through different positions, enabling precise detection of particle location through optical signal analysis
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 enhances particle detection and analysis capabilities, providing valuable information for lab-on-a-chip devices and point-of-care diagnostics, with improved throughput and accuracy in measuring particle distribution and velocity, and is suitable for various applications including clinical and industrial uses.
Implementation Method 1
a mask formed on one side of the microfluidic channel and structured to include a pattern of openings along the microfluidic channel, in which at least two of the openings have varying dimensions across the microfluidic channel, and in which the pattern of openings encodes a waveform on the probe light
Implementation Method 2
each particle scatters the light beam to produce an optical scattering signal at each position that the particle flows along the pattern of openings
Data Source
AI summary
Techniques, devices and systems are disclosed for characterizing particles in a fluid sample by optical space-time coding. In one aspect, a microfluidic device for optical detection of particles includes a substrate, a microfluidic channel formed on the substrate and structured to carry a fluid sample containing particles, in which the microfluidic channel is structured to transmit a probe light, and a mask formed on one side of the microfluidic channel and structured to include a pattern of openings along the microfluidic channel, in which at least two of the openings have varying dimensions across the microfluidic channel, and in which the pattern of openings encodes a waveform on the probe light that transmits through the microfluidic channel to allow optical detection of a position of a particle in the microfluidic channel.