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Childers K, Freed IM, Hupert ML, Shaw B, Larsen N, Herring P, Norton JH, Shiri F, Vun J, August KJ, Witek MA, Soper SA. Novel thermoplastic microvalves based on an elastomeric cyclic olefin copolymer. LAB ON A CHIP 2024; 24:4422-4439. [PMID: 39171671 PMCID: PMC11339931 DOI: 10.1039/d4lc00501e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2024] [Accepted: 08/12/2024] [Indexed: 08/23/2024]
Abstract
Microfluidic systems combine multiple processing steps and components to perform complex assays in an autonomous fashion. To enable the integration of several bio-analytical processing steps into a single system, valving is used as a component that directs fluids and controls introduction of sample and reagents. While elastomer polydimethylsiloxane has been the material of choice for valving, it does not scale well to accommodate disposable integrated systems where inexpensive and fast production is needed. As an alternative to polydimethylsiloxane, we introduce a membrane made of thermoplastic elastomeric cyclic olefin copolymer (eCOC), that displays unique attributes for the fabrication of reliable valving. The eCOC membrane can be extruded or injection molded to allow for high scale production of inexpensive valves. Normally hydrophobic, eCOC can be activated with UV/ozone to produce a stable hydrophilic monolayer. Valves are assembled following in situ UV/ozone activation of eCOC membrane and thermoplastic valve seat and bonded by lamination at room temperature. eCOC formed strong bonding with polycarbonate (PC) and polyethylene terephthalate glycol (PETG) able to hold high fluidic pressures of 75 kPa and 350 kPa, respectively. We characterized the eCOC valves with mechanical and pneumatic actuation and found the valves could be reproducibly actuated >50 times without failure. Finally, an integrated system with eCOC valves was employed to detect minimal residual disease (MRD) from a blood sample of a pediatric acute lymphoblastic leukemia (ALL) patient. The two module integrated system evaluated MRD by affinity-selecting CD19(+) cells and enumerating leukemia cells via immunophenotyping with ALL-specific markers.
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Affiliation(s)
- Katie Childers
- Bioengineering Program, The University of Kansas, Lawrence, KS 66045, USA.
- Center of BioModular Multiscale Systems for Precision Medicine, The University of Kansas, Lawrence, KS 66045, USA
| | - Ian M Freed
- Center of BioModular Multiscale Systems for Precision Medicine, The University of Kansas, Lawrence, KS 66045, USA
- Department of Chemistry, The University of Kansas, Lawrence, KS 66045, USA
| | | | - Benjamin Shaw
- Center of BioModular Multiscale Systems for Precision Medicine, The University of Kansas, Lawrence, KS 66045, USA
- Department of Chemical Engineering, The University of Kansas, Lawrence, KS 66045, USA
| | - Noah Larsen
- Center of BioModular Multiscale Systems for Precision Medicine, The University of Kansas, Lawrence, KS 66045, USA
- Department of Engineering Physics, The University of Kansas, Lawrence, KS 66045, USA
| | - Paul Herring
- Department of Plastics Engineering Technology, Pittsburg State University, Pittsburg, KS 66762, USA
| | - Jeanne H Norton
- Department of Plastics Engineering Technology, Pittsburg State University, Pittsburg, KS 66762, USA
| | - Farhad Shiri
- Center of BioModular Multiscale Systems for Precision Medicine, The University of Kansas, Lawrence, KS 66045, USA
- Department of Chemistry, The University of Kansas, Lawrence, KS 66045, USA
| | - Judy Vun
- Department of Pediatrics, Children's Mercy Hospital, Kansas City, MO 64108, USA
| | - Keith J August
- Department of Pediatrics, Children's Mercy Hospital, Kansas City, MO 64108, USA
| | - Małgorzata A Witek
- Center of BioModular Multiscale Systems for Precision Medicine, The University of Kansas, Lawrence, KS 66045, USA
- Department of Chemistry, The University of Kansas, Lawrence, KS 66045, USA
| | - Steven A Soper
- Bioengineering Program, The University of Kansas, Lawrence, KS 66045, USA.
- Center of BioModular Multiscale Systems for Precision Medicine, The University of Kansas, Lawrence, KS 66045, USA
- Department of Chemistry, The University of Kansas, Lawrence, KS 66045, USA
- Department of Mechanical Engineering, The University of Kansas, Lawrence, KS 66045, USA
- KU Cancer Center, University of Kansas Medical Center, Kansas City, KS 66160, USA
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Padmanabhan S, Han JY, Nanayankkara I, Tran K, Ho P, Mesfin N, White I, DeVoe DL. Enhanced sample filling and discretization in thermoplastic 2D microwell arrays using asymmetric contact angles. BIOMICROFLUIDICS 2020; 14:014113. [PMID: 32095199 PMCID: PMC7028432 DOI: 10.1063/1.5126938] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Accepted: 02/09/2020] [Indexed: 05/04/2023]
Abstract
Sample filling and discretization within thermoplastic 2D microwell arrays is investigated toward the development of low cost disposable microfluidics for passive sample discretization. By using a high level of contact angle asymmetry between the filling channel and microwell surfaces, a significant increase in the range of well geometries that can be successfully filled is revealed. The performance of various array designs is characterized numerically and experimentally to assess the impact of contact angle asymmetry and device geometry on sample filling and discretization, resulting in guidelines to ensure robust microwell filling and sample isolation over a wide range of well dimensions. Using the developed design rules, reliable and bubble-free sample filling and discretization is achieved in designs with critical dimensions ranging from 20 μm to 800 μm. The resulting devices are demonstrated for discretized nucleic acid amplification by performing loop-mediated isothermal amplification for the detection of the mecA gene associated with methicillin-resistant Staphylococcus aureus.
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Affiliation(s)
- S. Padmanabhan
- Department of Chemical and Biomolecular Engineering, University of Maryland, College Park, Maryland 20742, USA
| | - J. Y. Han
- Department of Mechanical Engineering, University of Maryland, College Park, Maryland 20742, USA
| | - I. Nanayankkara
- Department of Bioengineering, University of Maryland, College Park, Maryland 20742, USA
| | - K. Tran
- Department of Chemical and Biomolecular Engineering, University of Maryland, College Park, Maryland 20742, USA
| | - P. Ho
- Department of Chemical and Biomolecular Engineering, University of Maryland, College Park, Maryland 20742, USA
| | - N. Mesfin
- Department of Chemical and Biomolecular Engineering, University of Maryland, College Park, Maryland 20742, USA
| | - I. White
- Department of Bioengineering, University of Maryland, College Park, Maryland 20742, USA
| | - D. L. DeVoe
- Author to whom correspondence should be addressed:. Tel.: +1-301-405-8125
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Mauk MG, Song J, Liu C, Bau HH. Simple Approaches to Minimally-Instrumented, Microfluidic-Based Point-of-Care Nucleic Acid Amplification Tests. BIOSENSORS 2018; 8:E17. [PMID: 29495424 PMCID: PMC5872065 DOI: 10.3390/bios8010017] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Revised: 01/29/2018] [Accepted: 02/09/2018] [Indexed: 01/10/2023]
Abstract
Designs and applications of microfluidics-based devices for molecular diagnostics (Nucleic Acid Amplification Tests, NAATs) in infectious disease testing are reviewed, with emphasis on minimally instrumented, point-of-care (POC) tests for resource-limited settings. Microfluidic cartridges ('chips') that combine solid-phase nucleic acid extraction; isothermal enzymatic nucleic acid amplification; pre-stored, paraffin-encapsulated lyophilized reagents; and real-time or endpoint optical detection are described. These chips can be used with a companion module for separating plasma from blood through a combined sedimentation-filtration effect. Three reporter types: Fluorescence, colorimetric dyes, and bioluminescence; and a new paradigm for end-point detection based on a diffusion-reaction column are compared. Multiplexing (parallel amplification and detection of multiple targets) is demonstrated. Low-cost detection and added functionality (data analysis, control, communication) can be realized using a cellphone platform with the chip. Some related and similar-purposed approaches by others are surveyed.
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Affiliation(s)
- Michael G Mauk
- Mechanical Engineering and Applied Mechanics (MEAM), School of Engineering and Applied Science, University of Pennsylvania, Towne Building, 220 33rd Street, Philadelphia, PA 19104, USA.
| | - Jinzhao Song
- Mechanical Engineering and Applied Mechanics (MEAM), School of Engineering and Applied Science, University of Pennsylvania, Towne Building, 220 33rd Street, Philadelphia, PA 19104, USA.
| | - Changchun Liu
- Mechanical Engineering and Applied Mechanics (MEAM), School of Engineering and Applied Science, University of Pennsylvania, Towne Building, 220 33rd Street, Philadelphia, PA 19104, USA.
| | - Haim H Bau
- Mechanical Engineering and Applied Mechanics (MEAM), School of Engineering and Applied Science, University of Pennsylvania, Towne Building, 220 33rd Street, Philadelphia, PA 19104, USA.
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Han JY, Rahmanian OD, Kendall EL, Fleming N, DeVoe DL. Screw-actuated displacement micropumps for thermoplastic microfluidics. LAB ON A CHIP 2016; 16:3940-3946. [PMID: 27713994 DOI: 10.1039/c6lc00862c] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The fabrication of on-chip displacement pumps integrated into thermoplastic chips is explored as a simple and low cost method for achieving precise and programmable flow control for disposable microfluidic systems. The displacement pumps consist of stainless steel screws inserted into threaded ports machined into a thermoplastic substrate which also serve as on-chip reagent storage reservoirs. Three different methods for pump sealing are investigated to enable high pressure flows without leakage, and software-defined control of multiple pumps is demonstrated in a self-contained platform using a compact and self-contained microcontroller for operation. Using this system, flow rates ranging from 0.5-40 μl min-1 are demonstrated. The pumps are combined with on-chip burst valves to fully seal multiple reagents into fabricated chips while providing on-demand fluid distribution in a downstream microfluidic network, and demonstrated for the generation of size-tunable water-in-oil emulsions.
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Affiliation(s)
- J Y Han
- Department of Chemical and Biomolecular Engineering, University of Maryland, College Park, MD 20742, USA.
| | - O D Rahmanian
- Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742, USA
| | - E L Kendall
- Department of Mechanical Engineering, University of Maryland, College Park, MD 20742, USA
| | - N Fleming
- Department of Mechanical Engineering, University of Maryland, College Park, MD 20742, USA
| | - D L DeVoe
- Department of Chemical and Biomolecular Engineering, University of Maryland, College Park, MD 20742, USA. and Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742, USA and Department of Mechanical Engineering, University of Maryland, College Park, MD 20742, USA
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