Systems and methods for particle focusing in microchannels
Inventors
Aguirre, Gerson • Xia, Zheng • Kamalakshakurup, Gopakumar
Assignees
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Publication Number
US-12337320-B2
Publication Date
2025-06-24
Expiration Date
Abstract
A microfluidic system configured to focus particles suspended in a fluid. One general aspect includes a microfluidic system comprising one or more substrates and a focusing channel formed in the one or more substrates and spanning a length from an inlet to an outlet for receiving a flow of particles suspended in fluid, wherein the particles have a diameter (a) and the focusing channel has a hydraulic diameter (dh).
Core Innovation
The invention relates to a microfluidic chip for focusing a flow of sperm cells suspended in a fluid. The chip includes one or more substrates and a focusing channel formed in the substrates and spanning a length from an inlet to an outlet. The focusing channel includes a repetitively curved segment having a hydraulic diameter (Dh), followed by a straight portion disposed downstream of the repetitively curved segment.
The focusing channel geometry is constrained by relationships between sperm cell diameter (a) and hydraulic diameter (Dh), and by a curvature-to-hydraulic-diameter parameter. A ratio of the cell diameter to the hydraulic diameter of the channel (a/Dh) is between about 0.03 and about 0.06. A ratio of curvature (critical parameter “r”) to the hydraulic diameter (Dh) defined by the formula 2ra2/Dh3 is less than about 0.03.
The invention further describes focusing behavior within the chip using additional channel features and additional regions. The focusing channel’s internal geometry forms focused flow, and the chip may include one or more symmetrically shaped segments and one or more asymmetrically shaped segments within the repetitively curved segment. The chip can include a downstream taper within the straight portion, and can further include a secondary region comprising a secondary input downstream of the repetitively curved segment and/or an on-chip dilution element upstream of the repetitively curved segment.
Claims Coverage
The independent claims are clm-00001, clm-00009, and clm-00018. Each independent claim centers on a microfluidic chip for focusing a flow of sperm cells using a focusing channel with a repetitively curved segment, and each adds a different structural/functional limitation.
Geometric constraints for focusing channel with repetitively curved segment and downstream straight portion
A microfluidic chip for focusing a flow of sperm cells suspended in a fluid, where the focusing channel comprises a repetitively curved segment having a hydraulic diameter (Dh) and includes a straight portion disposed downstream, with a/Dh between about 0.03 and about 0.06 and 2ra2/Dh3 less than about 0.03.
On-chip dilution element upstream of repetitively curved segment with geometric constraints
A microfluidic chip for focusing a flow of sperm cells suspended in a fluid, where the focusing channel comprises a repetitively curved segment having a hydraulic diameter (Dh) and an on-chip dilution element upstream of the repetitively curved segment, with a/Dh between about 0.03 and about 0.06 and 2ra2/Dh3 less than about 0.03.
Secondary region with secondary input downstream of repetitively curved segment with geometric constraints
A microfluidic chip for focusing a flow of sperm cells suspended in a fluid, where the focusing channel comprises a repetitively curved segment having a hydraulic diameter (Dh) and further includes a secondary region comprising a secondary input downstream of the repetitively curved segment, with a/Dh between about 0.03 and about 0.06 and 2ra2/Dh3 less than about 0.03.
Across the independent claims, the core coverage is the use of a focusing channel with a repetitively curved segment configured by specific geometric relationships involving a, Dh, and 2ra2/Dh3, combined with either a downstream straight portion, an upstream on-chip dilution element, or a downstream secondary region with a secondary input.
Stated Advantages
Not explicitly described in patent.
Documented Applications
Not explicitly described in patent.
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