Microfluidic Cell Concentration Control via Impedance Sensors
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Solution Overview
Problem
The life sciences and diagnostics industries face challenges in reducing costs, increasing throughput, and optimizing patient sample utilization, which existing macrofluidic systems fail to address effectively, particularly in achieving precise cell concentration for microfluidic assays.
Innovation Solution
A microfluidic apparatus with a die including a microfluidic chamber, impedance-based sensors, and nozzles for controlled cell concentration, where inlet and output sensors direct cell-containing fluid to target or spittoon locations based on impedance measurements, allowing for precise control of cell concentration using circuitry to manage nozzle firing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If macrofluidic systems are used for cell concentration control, then device complexity is reduced, but manufacturing precision of cell concentration deteriorates
Solution Approach 1:
The system is divided into multiple independent focal regions within the microfluidic chamber, each capable of concentrating cells to a specific target concentration. This segmentation allows precise control of cell concentration in discrete zones while maintaining overall system simplicity.
Solution Approach 2:
The patent replaces complex mechanical concentration control mechanisms with electrical signaling and automated nozzle firing. Impedance sensors detect cell positions and trigger electronic control signals that activate specific nozzles, substituting mechanical complexity with electronic control for superior precision.
2Manufacturing precision
If microfluidic systems are used for cell concentration control, then manufacturing precision of cell concentration is improved, but device complexity increases
Solution Approach 1:
The microfluidic chamber serves multiple functions: it contains impedance sensors for detection, focal regions for concentration control, and nozzles for dispensing. This multi-functionality reduces the need for separate dedicated components, thereby controlling overall device complexity while achieving precise cell concentration control.
Solution Approach 2:
The system uses impedance sensors within the microfluidic chamber to automatically detect cell positions and trigger nozzle firing without external intervention. This self-service capability reduces the need for complex external control mechanisms while maintaining high precision in cell concentration control.
3Device complexity
If conventional dispensing methods are used, then device complexity is low, but loss of time in achieving target concentration increases
Solution Approach 1:
The system pre-positions multiple nozzles at specific locations within the microfluidic chamber, each corresponding to a target concentration level. When cells are detected by impedance sensors, the appropriate pre-positioned nozzle is immediately activated, eliminating the time required to locate and set up dispensing positions during the process.
Solution Approach 2:
The impedance sensors continuously monitor cell positions and the system continuously adjusts nozzle firing to maintain optimal cell concentration. This continuous detection and adjustment eliminates idle time and ensures uninterrupted processing, significantly reducing total processing time compared to conventional batch methods.
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 efficient and precise control of cell concentration in microfluidic systems, maximizing the number of cells dispensed to target locations while minimizing waste, thereby enhancing assay measurement efficiency and reducing sample requirements.
Implementation Method 1
an inlet impedance-based sensor to detect passage of a cell of the biologic sample into the foyer
Data Source
AI summary
An apparatus including a fluidic input and a die including a microfluidic chamber, may receive a biologic sample. The microfluidic chamber may include a foyer to contain a portion of the biologic sample, and an inlet impedance-based sensor to detect passage of a cell of the biologic sample into the foyer. A target nozzle may eject a first volume, corresponding with a target concentration of cells of the biologic sample. A spittoon nozzle may eject a second volume of the portion of the biologic sample into a spittoon location. An output impedance-based sensor may be disposed within a threshold distance of the target nozzle to detect passage of a cell of the biologic sample into the target nozzle. Moreover, the apparatus may include circuitry to control firing of the target nozzle and the spittoon nozzle based on signals received from the inlet impedance-based sensor and the output impedance-based sensor.