Microfluidic Ferrofluid Sorting via Magnetic Field Patterns
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Solution Overview
Problem
Current methods for separating target species in biocompatible ferrofluids face challenges in achieving high throughput, resolution, and cost-effectiveness simultaneously, with existing techniques like optical tweezers causing sample heating, DEP methods requiring optimization for each cell type, and deterministic hydrodynamics being costly due to high-resolution lithography requirements.
Innovation Solution
A microfluidic device with a channel traversing electrodes that generates a magnetic field pattern using a power source, allowing for the separation of target species based on size, shape, and elasticity, with a biocompatible ferrofluid maintaining osmotic pressure and pH stability, enabling efficient and rapid separation of microparticles and live cells.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If optical tweezers are used to manipulate target species, then high resolution and sensitivity are achieved, but sample heating occurs and manipulation area is limited
Solution Approach 1:
The patent replaces optical tweezers (optical field) with a magnetic field-based system using electrodes to generate magnetic fields that manipulate ferrofluid-containing target species. This substitution eliminates optical heating while maintaining manipulation capability through magnetic field interactions with the ferrofluid.
2Ease of manufacture
If DEP methods are used to manipulate multiple cells, then integrated cost-effective devices are realized, but performance depends sensitively on electrical properties and requires careful optimization for each cell type
Solution Approach 1:
The patent changes the fundamental manipulation parameter from electrical fields (DEP) to magnetic fields. By using magnetic field generation through electrodes acting on ferrofluid, the system achieves cost-effectiveness while reducing sensitivity to specific electrical properties of different cell types, as magnetic properties of ferrofluid are more uniform and controllable.
3Reliability
If magnetic bead-based separators are used, then challenges of DEP are overcome, but lengthy incubation times and wash cycles occur and label removal is difficult
Solution Approach 1:
The patent extracts the magnetic bead label from the system by using directly magnetizable ferrofluid in the sample itself. This eliminates the need for external magnetic beads, thereby removing the time-consuming incubation and wash cycles required to attach and detach labels, while maintaining reliable magnetic manipulation.
4Measurement precision
If deterministic hydrodynamics approach is used, then high resolution separation is achieved without electromagnetic fields, but high throughput requires high-resolution lithography on large area keeping cost per device high
Solution Approach 1:
The patent replaces deterministic hydrodynamics (mechanical flow control) with magnetic field-based manipulation. This substitution enables high-resolution separation through magnetic field gradients acting on ferrofluid without requiring complex high-resolution lithography patterns, thereby reducing manufacturing cost while maintaining separation resolution.
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 high-throughput, label-free sorting with over 90% efficiency and sub-10 µm resolution in under a minute, significantly reducing incubation times and increasing diagnostic sensitivity by exploiting differences in particle attributes.
Implementation Method 1
a power source configured to controllably apply at least one current to the plurality of electrodes to controllably generate a magnetic field pattern along at least a portion of the channel length
Implementation Method 2
The biocompatible ferrofluid may include a suitable amount of ionic species to control the osmotic pressure on the cells to promote cell sustainability
Data Source
Figure 1A~1D
Figure 2A~2B
Figure 3A
AI summary
Disclosed are systems, devices, methods, and other implementations, including a device to detect at least one target species in a sample, with the device including a microfluidic channel configured to receive the sample containing the at least one target species and a biocompatible ferrofluid in which the at least one target species is suspended, a detector to determine the at least one target species in the sample, and at least two of electrodes positioned proximate the microfluidic channel, the at least two electrodes configured to generate controllable magnetic forces in the sample containing the ferrofluid when a controllable at least one electrical current is applied to the at least two electrodes. The generated controllable magnetic forces causes the at least one target species to be directed towards the detector. Also disclosed are devices for separating target species in a ferrofluid, and for focusing target species suspended in a ferrofluid.