To improve tools for controlling and optimizing miniaturized chemistry, a novel oil extraction architecture, designated as the Counter-Current Continuous Phase Extraction (C3PE) module, was developed to enable precise control over reaction incubation in water-in-oil droplet microfluidic reactors. Using a symmetric pillar array coupled to adjustable oil flows prevented sample loss and droplet breakup, even at high final volume fractions, and cross-flow added novel stabilization of oil extraction against instability in control pressures. By integrating this dynamic functionality, C3PE enabled rational selection of the oil extraction magnitude across a range of achievable final droplet volume fractions (up to 85%) when processing droplets at 40–200 Hz. Further, this versatile device handled many droplet sizes (70–500 pL demonstrated here). Next, this approach to controlling droplet volume fraction enabled incubation time monitoring and optimization when coupled to a K-channel direct injection feature to label selected droplets. In profiling system characteristics like volume fraction, channel geometry, and continuous phase viscosity, this technique provided a powerful tool to control, measure, and improve incubation performance. Finally, applying C3PE principles to an in-droplet β-galactosidase enzyme reaction (useful in immunoassay systems) increased product formation while significantly decreasing variance in product yield among droplets relative to a non-extracted comparison. We envision that this method will inform future design and implementation of high precision in-droplet chemistry while being of general interest in the study of emulsion fluid dynamics.
This is a preview of subscription content, log in to check access.
Buy single article
Instant access to the full article PDF.
Price includes VAT for USA
Subscribe to journal
Immediate online access to all issues from 2019. Subscription will auto renew annually.
This is the net price. Taxes to be calculated in checkout.
Abate AR, Hung T, Mary P, Agresti JJ, Weitz DA (2010) High-throughput injection with microfluidics using picoinjectors. Proc Natl Acad Sci USA 107:19163–19166. https://doi.org/10.1073/pnas.1006888107
Baret J-C (2012) Surfactants in droplet-based microfluidics. Lab Chip 12:422–433. https://doi.org/10.1039/C1LC20582J
Basu AS (2013) Droplet morphometry and velocimetry (DMV): a video processing software for time-resolved, label-free tracking of droplet parameters. Lab Chip 13:1892–1901. https://doi.org/10.1039/C3LC50074H
Brouzes E, Kruse T, Kimmerling R, Strey HH (2015) Rapid and continuous magnetic separation in droplet microfluidic devices. Lab Chip 15:908–919. https://doi.org/10.1039/C4LC01327A
Choi N, Lee J, Ko J, Jeon JH, Rhie G-e, deMello AJ, Choo J (2017) Integrated SERS-based microdroplet platform for the automated immunoassay of F1 antigens in yersinia pestis. Anal Chem 89:8413–8420. https://doi.org/10.1021/acs.analchem.7b01822
Chong ZZ, Tor SB, Gañán-Calvo AM, Chong ZJ, Loh NH, Nguyen N-T, Tan SH (2016) Automated droplet measurement (ADM): an enhanced video processing software for rapid droplet measurements. Microfluid Nanofluid 20:66. https://doi.org/10.1007/s10404-016-1722-5
Chung MT, Nunez D, Cai D, Kurabayashi K (2017) Deterministic droplet-based co-encapsulation and pairing of microparticles via active sorting and downstream merging. Lab Chip 17:3664–3671. https://doi.org/10.1039/C7LC00745K
Cochrane WG, Hackler AL, Cavett VJ, Price AK, Paegel BM (2017) Integrated, continuous emulsion creamer. Anal Chem 89:13227–13234. https://doi.org/10.1021/acs.analchem.7b03070
Doonan SR, Bailey RC (2017) K-channel: a multifunctional architecture for dynamically reconfigurable sample processing in droplet microfluidics. Anal Chem 89:4091–4099. https://doi.org/10.1021/acs.analchem.6b05041
Doonan SR, Lin M, Bailey RC (2019) Droplet CAR-wash: continuous picoliter-scale immunocapture and washing. Lab Chip. https://doi.org/10.1039/C9LC00125E
Frenz L, Blank K, Brouzes E, Griffiths AD (2009) Reliable microfluidic on-chip incubation of droplets in delay-lines. Lab Chip 9:1344–1348. https://doi.org/10.1039/B816049J
Gach PC, Iwai K, Kim PW, Hillson NJ, Singh AK (2017) Droplet microfluidics for synthetic biology. Lab Chip 17:3388–3400. https://doi.org/10.1039/C7LC00576H
Garstecki P, Fuerstman MJ, Stone HA, Whitesides GM (2006) Formation of droplets and bubbles in a microfluidic T-junction-scaling and mechanism of break-up. Lab Chip 6:437–446. https://doi.org/10.1039/B510841A
Haliburton JR, Kim SC, Clark IC, Sperling RA, Weitz DA, Abate AR (2017) Efficient extraction of oil from droplet microfluidic emulsions. Biomicrofluidics 11:034111. https://doi.org/10.1063/1.4984035
Huang H, Yu Y, Hu Y, He X, Berk Usta O, Yarmush ML (2017) Generation and manipulation of hydrogel microcapsules by droplet-based microfluidics for mammalian cell culture. Lab Chip 17:1913–1932. https://doi.org/10.1039/C7LC00262A
Huebner A, Bratton D, Whyte G, Yang M, deMello AJ, Abell C, Hollfelder F (2009) Static microdroplet arrays: a microfluidic device for droplet trapping, incubation and release for enzymatic and cell-based assays. Lab Chip 9:692–698. https://doi.org/10.1039/B813709A
Jayaprakash KS, Banerjee U, Sen AK (2016) Dynamics of aqueous droplets at the interface of coflowing immiscible oils in a microchannel. Langmuir 32:2136–2143. https://doi.org/10.1021/acs.langmuir.5b04116
Kaoui B, Ristow GH, Cantat I, Misbah C, Zimmermann W (2008) Lateral migration of a two-dimensional vesicle in unbounded Poiseuille flow. Phys Rev E 77:021903. https://doi.org/10.1103/PhysRevE.77.021903
Lan F, Demaree B, Ahmed N, Abate AR (2017) Single-cell genome sequencing at ultra-high-throughput with microfluidic droplet barcoding. Nat Biotechnol 35:640–646. https://doi.org/10.1038/nbt.3880
Lee M et al (2014) Synchronized reinjection and coalescence of droplets in microfluidics. Lab Chip 14:509–513. https://doi.org/10.1039/C3LC51214B
Li S et al (2013) An on-chip, multichannel droplet sorter using standing surface acoustic waves. Anal Chem 85:5468–5474. https://doi.org/10.1021/ac400548d
Lombardi D, Dittrich PS (2011) Droplet microfluidics with magnetic beads: a new tool to investigate drug–protein interactions. Anal Bioanal Chem 399:347–352. https://doi.org/10.1007/s00216-010-4302-7
Mary P, Abate AR, Agresti JJ, Weitz DA (2011) Controlling droplet incubation using close-packed plug flow. Biomicrofluidics 5:024101. https://doi.org/10.1063/1.3576934
Mazutis L, Gilbert J, Ung WL, Weitz DA, Griffiths AD, Heyman JA (2013) Single-cell analysis and sorting using droplet-based microfluidics. Nat Protoc 8:870–891. https://doi.org/10.1038/nprot.2013.046
Oh KW, Lee K, Ahn B, Furlani EP (2012) Design of pressure-driven microfluidic networks using electric circuit analogy. Lab Chip 12:515–545. https://doi.org/10.1039/C2LC20799K
Rhee M, Light YK, Yilmaz S, Adams PD, Saxena D, Meagher RJ, Singh AK (2014) Pressure stabilizer for reproducible picoinjection in droplet microfluidic systems. Lab Chip 14:4533–4539. https://doi.org/10.1039/C4LC00823E
Sahore V, Doonan SR, Bailey RC (2018) Droplet microfluidics in thermoplastics: device fabrication, droplet generation, and content manipulation using integrated electric and magnetic fields. Anal Methods 10:4264–4274. https://doi.org/10.1039/C8AY01474D
Sciambi A, Abate AR (2014) Generating electric fields in PDMS microfluidic devices with salt water electrodes. Lab Chip 14:2605–2609. https://doi.org/10.1039/C4LC00078A
Shang L, Cheng Y, Zhao Y (2017) Emerging droplet microfluidics. Chem Rev 117:7964–8040. https://doi.org/10.1021/acs.chemrev.6b00848
Song H, Tice JD, Ismagilov RF (2003) A microfluidic system for controlling reaction networks in time. Angew Chem Int Ed 42:768–772. https://doi.org/10.1002/anie.200390203
Squires TM, Quake SR (2005) Microfluidics: fluid physics at the nanoliter scale. Rev Mod Phys 77:977–1026. https://doi.org/10.1103/RevModPhys.77.977
Sun M, Vanapalli SA (2013) Generation of chemical concentration gradients in mobile droplet arrays via fragmentation of long immiscible diluting plugs. Anal Chem 85:2044–2048. https://doi.org/10.1021/ac303526y
Teh S-Y, Lin R, Hung L-H, Lee AP (2008) Droplet microfluidics. Lab Chip 8:198–220. https://doi.org/10.1039/B715524G
Thorsen T, Roberts RW, Arnold FH, Quake SR (2001) Dynamic pattern formation in a vesicle-generating microfluidic device. Phys Rev Lett 86:4163–4166. https://doi.org/10.1103/PhysRevLett.86.4163
Verbruggen B, Leirs K, Puers R, Lammertyn J (2015) Selective DNA extraction with microparticles in segmented flow. Microfluid Nanofluid 18:293–303. https://doi.org/10.1007/s10404-014-1433-8
Xi H-D et al (2017) Active droplet sorting in microfluidics: a review. Lab Chip 17:751–771. https://doi.org/10.1039/C6LC01435F
Xia Y, Whitesides GM (1998) Soft lithography. Angew Chem Int Ed 37:550–575. https://doi.org/10.1002/(SICI)1521-3773(19980316)37:5<550:AID-ANIE550>3.0.CO;2-G
Xu Y, Lee J-H, Li Z, Wang L, Ordog T, Bailey RC (2018) A droplet microfluidic platform for efficient enzymatic chromatin digestion enables robust determination of nucleosome positioning. Lab Chip 18:2583–2592. https://doi.org/10.1039/C8LC00599K
Zilionis R, Nainys J, Veres A, Savova V, Zemmour D, Klein AM, Mazutis L (2016) Single-cell barcoding and sequencing using droplet microfluidics. Nat Protoc 12:44–73. https://doi.org/10.1038/nprot.2016.154
We gratefully acknowledge financial support from the National Institutes of Health (NIH CA191186). S.R.D. was supported by the National Science Foundation Graduate Research Fellowship Program. M.L. was supported by the Pfizer Undergraduate Summer Research Award (University of Michigan). We also want to thank Prof. Robert Kennedy and Dr. Brian Shay (University of Michigan) for assistance with viscosity measurements.
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
About this article
Cite this article
Doonan, S.R., Lin, M., Lee, D. et al. C3PE: counter-current continuous phase extraction for improved precision of in-droplet chemical reactions. Microfluid Nanofluid 24, 50 (2020). https://doi.org/10.1007/s10404-020-02354-2
- Droplet microfluidics
- Volume fraction