Method for reagent-specific driving EWoD arrays in microfluidic systems
Inventors
Paolini, Jr., Richard J. • Slominski, Luke M. • O'Malley, Timothy J. • ZHITOMIRSKY, David
Assignees
Publication Number
US-12179203-B2
Publication Date
2024-12-31
Expiration Date
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Abstract
An electrowetting system for actuating droplets of a first composition and of a second composition. The system includes: a plurality of electrodes configured to manipulate droplets of fluid in a microfluidic space, each electrode being coupled to circuitry which applies driving voltages to the electrode; and a processing unit operably connected to a look up table correlating drive sequences to chemical species and at least one composition parameter. The processing unit is configured to: receive data of a first chemical species and a first composition parameter of the first composition; receive data of a second chemical species and a second composition parameter of the second composition; correlate a first drive sequence with the first chemical species and the first composition parameter; correlate a second drive sequence with the second chemical species and the second composition parameter; and output the first drive sequence and the second drive sequence to the electrodes.
Core Innovation
An electrowetting system for actuating droplets of a first composition and of a second composition is provided, the system comprising a plurality of electrodes configured to manipulate droplets of fluid in a microfluidic space, each electrode coupled to circuitry configured to selectively apply driving voltages to the electrode, and a processing unit operably connected to a look up table correlating drive sequences to chemical species and at least one composition parameter. The processing unit is configured to receive input data of chemical species and composition parameters for droplets, to correlate drive sequences with those chemical species and composition parameters, and to output the correlated drive sequences to the plurality of electrodes.
Embodiments include a method for performing droplet operations in an electrowetting system in which the processing unit receives input data of chemical species and composition parameters for first and second compositions, correlates a first drive sequence with the first chemical species and composition parameter, correlates a second drive sequence with the second chemical species and composition parameter, and outputs the first and second drive sequences to the plurality of electrodes. Additional embodiments include actuating a mixed droplet by providing first and second droplets correlated with respective drive sequences, mixing the droplets to create a mixed droplet, and driving the mixed droplet with a third drive sequence that is a predetermined weighted average of the first and second drive sequences.
The background identifies limitations addressed by the invention, including that segmented EWoD devices are limited in electrode count and designed for specific applications, which can impede massive parallel assays, and that implementing the same drive scheme for different chemical compositions may result in sub-optimal droplet actuation and may induce undesired electrochemical reactions and corrosion of working surfaces. The invention provides adaptable drive schemes and reagent-specific drive profiles to tailor voltages and durations of driving pulses to droplet composition, droplet location on the array, and the operation to be performed.
Claims Coverage
Independent claim 1 identifies four main inventive features.
Active matrix AM-EWoD with transistor-switched pixel electrodes
An active matrix electrowetting on dielectric (AM-EWoD) system comprising a plurality of pixel electrodes disposed in the AM-EWoD system, wherein the pixel electrodes are switched by a transistor matrix comprising a plurality of transistors, each transistor operably connected to a gate line, to a source line, and to the pixel electrodes.
Parallel droplet operations with distinct drive sequences
Performing plurality of droplet operations on first and second pluralities of droplets in parallel by driving pixel electrodes with a first drive sequence having a first series of voltage pulses and with a second drive sequence having a second series of voltage pulses, wherein the first series differs from the second series.
Drive sequences comprising mixed high and low voltage pulses
Each voltage pulse sequence of the first and second series includes a mix of high voltage pulses and of low voltage pulses.
Differing intermittency between drive sequences
Each voltage pulse sequence of the first series of voltage pulses differs in intermittency from each voltage pulse sequence of the second series of voltage pulses.
Claim 1 covers an AM-EWoD method combining a transistor-switched pixel matrix with reagent-differentiated, parallel drive sequences that use mixed high/low voltage pulses and differ in intermittency.
Stated Advantages
Enables tailoring drive sequences to individual chemical species and composition parameters to bring to completion each desired droplet operation.
Facilitates parallel droplet operations on different compositions using an active matrix with many addressable electrodes, supporting massive parallelization of assays and reactions.
Use of charge-neutral or corrected drive sequences reduces residual surface charge and minimizes electrochemical damage and corrosion to device surfaces.
Lookup table storage of reagent-specific drive profiles allows selection and reuse of drive schemes matched to standardized compositions or individually determined reagent profiles.
Documented Applications
Sample preparation, assays, and synthetic chemistry performed with tiny quantities of samples and reagents (lab-on-a-chip applications).
Biochemical and biomolecular protocols including nucleic acid amplification, affinity-based assays, enzymatic assays, gene sequencing, protein sequencing, and analyses of biological fluids.
Droplet operations such as loading, dispensing from reservoirs, splitting, moving, merging, diluting, mixing, deforming, holding, incubating, heating, vaporizing, cooling, disposing of, and transporting droplets in a microfluidic space.
Use in AM-EWoD devices and TFT-based active matrix backplanes to enable mass parallelization of droplet procedures and programmable fluidic processing.
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