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Joseph K, Ibrahim F, Qureshi S, Petrović B, Kojić S, Thiha A, Jamaluddin N, Dahlan N, Stojanović G. Enhanced Sweat Biosensing with Thread-Embedded Microfluidic Devices. Med Sci Monit 2024; 30:e943321. [PMID: 38863180 PMCID: PMC11181877 DOI: 10.12659/msm.943321] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Accepted: 03/21/2024] [Indexed: 06/13/2024] Open
Abstract
BACKGROUND This study explored the integration of conductive threads into a microfluidic compact disc (CD), developed using the xurographic method, for a potential sweat biosensing platform. MATERIAL AND METHODS The microfluidic CD platform, fabricated using the xurographic method with PVC films, included venting channels and conductive threads linked to copper electrodes. With distinct microfluidic sets for load and metering, flow control, and measurement, the CD's operation involved spinning for sequential liquid movement. Impedance analysis using HIOKI IM3590 was conducted for saline and artificial sweat solutions on 4 identical CDs, ensuring reliable conductivity and measurements over a 1 kHz to 200 kHz frequency range. RESULTS Significant differences in |Z| values were observed between saline and artificial sweat treatments. 27.5 μL of saline differed significantly from 27.5 μL of artificial sweat, 72.5 μL of saline from 72.5 μL of artificial sweat, and 192.5 μL of saline from 192.5 μL of sweat. Significant disparities in |Z| values were observed between dry fibers and Groups 2, 3, and 4 (varying saline amounts). No significant differences emerged between dry fibers and Groups 6, 7, and 8 (distinct artificial sweat amounts). These findings underscore variations in fiber characteristics between equivalent exposures, emphasizing the nuanced response of the microfluidic CD platform to different liquid compositions. CONCLUSIONS This study shows the potential of integrating conductive threads in a microfluidic CD platform for sweat sensing. Challenges in volume control and thread coating degradation must be addressed for transformative biosensing devices in personalized healthcare.
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Affiliation(s)
- Karunan Joseph
- Department of Biomedical Engineering and Centre for Innovation in Medical Engineering (CIME),Universiti Malaya, Kuala Lumpur, Malaysia
| | - Fatimah Ibrahim
- Department of Biomedical Engineering and Centre for Innovation in Medical Engineering (CIME),Universiti Malaya, Kuala Lumpur, Malaysia
| | - Saima Qureshi
- Faculty of Technical Sciences, University of Novi Sad, Novi Sad, Serbia
| | - Bojan Petrović
- Faculty of Medicine, University of Novi Sad, Novi Sad, Serbia
| | - Sanja Kojić
- Faculty of Technical Sciences, University of Novi Sad, Novi Sad, Serbia
| | - Aung Thiha
- Department of Biomedical Engineering and Centre for Innovation in Medical Engineering (CIME),Universiti Malaya, Kuala Lumpur, Malaysia
| | - Nurul Jamaluddin
- Department of Biomedical Engineering and Centre for Innovation in Medical Engineering (CIME),Universiti Malaya, Kuala Lumpur, Malaysia
| | - Nuraina Dahlan
- Department of Biomedical Engineering and Centre for Innovation in Medical Engineering (CIME),Universiti Malaya, Kuala Lumpur, Malaysia
| | - Goran Stojanović
- Faculty of Technical Sciences, University of Novi Sad, Novi Sad, Serbia
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Vloemans D, Pieters A, Dal Dosso F, Lammertyn J. Revolutionizing sample preparation: a novel autonomous microfluidic platform for serial dilution. LAB ON A CHIP 2024; 24:2791-2801. [PMID: 38691394 DOI: 10.1039/d4lc00195h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2024]
Abstract
Dilution is a standard fluid operation widely employed in the sample preparation process of many bio(chemical) assays. It serves multiple essential functions such as sample mixing with certain reagents at specific dilution ratios, reducing sample matrix effects, bringing target analytes within the linear assay detection range, among many others. Traditionally, sample processing is performed in laboratory settings through manual or automated pipetting. When working in resource-limited settings, however, neither trained personnel nor proper laboratory equipment are available limiting the accessibility to high-quality diagnostic tests. In this work, we present a novel standalone and fully automated microfluidic platform for the stepwise preparation of serial dilutions without the need for any active elements. Stepwise dilution is achieved using the coordinated burst action of hydrophobic burst valves to first isolate a precisely metered volume from an applied sample drop and subsequently merge it with a prefilled diluent liquid. Downstream, expansion chambers are used to mix both reagents into a homogeneous solution. The dilution module was characterized to generate accurate and reproducible (CV < 7%) dilutions for targeted dilution factors of 2, 5 and 10×, respectively. Three dilution modules were coupled in series to generate three-fold logarithmic (log5 or log10) dilutions, with excellent linearity (R2 > 0.99). Its compatibility with whole blood was furthermore illustrated, proving its applicability for automating and downscaling bioassays with complex biological matrices. Finally, autonomous on-chip serial dilution was demonstrated by incorporating the self-powered (i)SIMPLE technology as a passive driving source for liquid manipulation. We believe that the simplicity and modularity of the presented autonomous dilution platform are of interest to many point-of-care applications in which sample dilution and reagent mixing are of importance.
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Affiliation(s)
- Dries Vloemans
- KU Leuven, Department of Biosystems, Biosensors Group, Willem de Croylaan 42, box 2428, 3001 Leuven, Belgium.
| | - Alexander Pieters
- KU Leuven, Department of Biosystems, Biosensors Group, Willem de Croylaan 42, box 2428, 3001 Leuven, Belgium.
| | - Francesco Dal Dosso
- KU Leuven, Department of Biosystems, Biosensors Group, Willem de Croylaan 42, box 2428, 3001 Leuven, Belgium.
| | - Jeroen Lammertyn
- KU Leuven, Department of Biosystems, Biosensors Group, Willem de Croylaan 42, box 2428, 3001 Leuven, Belgium.
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Khodadadi R, Pishbin E, Eghbal M, Abrinia K. Real-time monitoring and actuation of a hybrid siphon valve for hematocrit-independent plasma separation from whole blood. Analyst 2023; 148:5456-5468. [PMID: 37750420 DOI: 10.1039/d3an00862b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/27/2023]
Abstract
Centrifugal microfluidics have emerged as a pivotal area of research spanning multiple domains, including medicine and chemistry. Among passive valving strategies, siphon valves have gained prominence due to their inherent simplicity and self-reliance, eliminating the need for external equipment. However, achieving optimal valve performance mandates supplementary elements like surface adjustments or pneumatic pressure. These introduce intricacies such as time-dependent behavior and augmented spatial demands. This research introduces inventive design and manufacturing methodologies to amplify siphon valve functionality. Our proposed innovation situates the siphon microchannel on the external surface of the primary chamber, linked via an inlet. The crux of novelty lies in the adaptable material selection for the microchannel's upper or lower surfaces, allowing the integration of hydrophilic materials such as glass or super hydrophilic coverslips, ensuring a leakage-free operation. Our approach offers a streamlined concept and manufacturing process, ensures consistent time-independent functionality, and accommodates the integration of multiple siphon valves within a solitary chamber, tailored for specific applications. Experimental evaluations validate a robust alignment between acquired data and analytical outcomes based on a modified equation. A customized disc is engineered, featuring four siphon valves meticulously calibrated for hematocrit (HCT) levels spanning from 20% to 50% at 10% intervals. Harnessing these valves yields a substantial surge in plasma separation efficiency, scaling up to 75%. Notably, this performance eclipses traditional single-valve reliant microfluidic methodologies, achieving a purity level exceeding 99% in plasma separation. These findings underscore the auspicious practical applicability of our proposed technique in plasma separation, fostering heightened platelet concentration, and expediting blood sample analysis.
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Affiliation(s)
- Reza Khodadadi
- School of Mechanical Engineering, University of Tehran, Tehran, Iran
| | - Esmail Pishbin
- Bio-microfluidics Laboratory, Department of Electrical Engineering and Information Technology, Iranian Research Organization for Science and Technology, Tehran, Iran.
| | - Manouchehr Eghbal
- Bio-microfluidics Laboratory, Department of Electrical Engineering and Information Technology, Iranian Research Organization for Science and Technology, Tehran, Iran.
| | - Karen Abrinia
- School of Mechanical Engineering, University of Tehran, Tehran, Iran
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4
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Early PL, Kilcawley NA, McArdle NA, Renou M, Kearney SM, Mishra R, Dimov N, Glynn MT, Ducrée J, Kinahan DJ. Digital process control of multi-step assays on centrifugal platforms using high-low-high rotational-pulse triggered valving. PLoS One 2023; 18:e0291165. [PMID: 37682949 PMCID: PMC10490917 DOI: 10.1371/journal.pone.0291165] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Accepted: 08/23/2023] [Indexed: 09/10/2023] Open
Abstract
Due to their capability for comprehensive sample-to-answer automation, the interest in centrifugal microfluidic systems has greatly increased in industry and academia over the last quarter century. The main applications of these "Lab-on-a-Disc" (LoaD) platforms are in decentralised bioanalytical point-of-use / point-of-care testing. Due to the unidirectional and omnipresent nature of the centrifugal force, advanced flow control is key to coordinate multi-step / multi-reagent assay formats on the LoaD. Formerly, flow control was often achieved by capillary burst valves which require gradual increments of the spin speed of the system-innate spindle motor. Recent advanced introduced a flow control scheme called 'rotational pulse actuated valves'. In these valves the sequence of valve actuation is determined by the architecture of the disc while actuation is triggered by freely programmable upward spike (i.e. Low-High-Low (LHL)) in the rotational frequency. This paradigm shift from conventional 'analogue' burst valves to 'digital' pulsing significantly increases the number of sequential while also improving the overall robustness of flow control. In this work, we expand on these LHL valves by introducing High-Low-High (HLH) pulse-actuated (PA) valving which are actuated by 'downward' spike in the disc spin-rate. These HLH valves are particularly useful for high spin-rate operations such as centrifugation of blood. We introduce two different HLH architectures and then combine the most promising with LHL valves to implement the time-dependent liquid handling protocol underlying a common liver function test panel.
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Affiliation(s)
- Philip L. Early
- School of Physical Sciences, Dublin City University, Glasnevin, Dublin, Ireland
- National Centre for Sensor Research, Dublin City University, Glasnevin, Dublin, Ireland
| | - Niamh A. Kilcawley
- School of Physical Sciences, Dublin City University, Glasnevin, Dublin, Ireland
- National Centre for Sensor Research, Dublin City University, Glasnevin, Dublin, Ireland
| | - Niamh A. McArdle
- School of Physical Sciences, Dublin City University, Glasnevin, Dublin, Ireland
- National Centre for Sensor Research, Dublin City University, Glasnevin, Dublin, Ireland
| | - Marine Renou
- School of Physical Sciences, Dublin City University, Glasnevin, Dublin, Ireland
- National Centre for Sensor Research, Dublin City University, Glasnevin, Dublin, Ireland
- Telecom Physique Strasbourg, Université de Strasbourg, Strasbourg, France
| | - Sinéad M. Kearney
- School of Physical Sciences, Dublin City University, Glasnevin, Dublin, Ireland
- National Centre for Sensor Research, Dublin City University, Glasnevin, Dublin, Ireland
| | - Rohit Mishra
- School of Physical Sciences, Dublin City University, Glasnevin, Dublin, Ireland
- National Centre for Sensor Research, Dublin City University, Glasnevin, Dublin, Ireland
| | - Nikolay Dimov
- School of Physical Sciences, Dublin City University, Glasnevin, Dublin, Ireland
- National Centre for Sensor Research, Dublin City University, Glasnevin, Dublin, Ireland
| | - Macdara T. Glynn
- School of Physical Sciences, Dublin City University, Glasnevin, Dublin, Ireland
- National Centre for Sensor Research, Dublin City University, Glasnevin, Dublin, Ireland
| | - Jens Ducrée
- School of Physical Sciences, Dublin City University, Glasnevin, Dublin, Ireland
- National Centre for Sensor Research, Dublin City University, Glasnevin, Dublin, Ireland
| | - David J. Kinahan
- School of Physical Sciences, Dublin City University, Glasnevin, Dublin, Ireland
- School of Mechanical and Manufacturing Engineering, Dublin City University, Glasnevin, Dublin, Ireland
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5
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Peshin S, Madou M, Kulinsky L. Microvalves for Applications in Centrifugal Microfluidics. SENSORS (BASEL, SWITZERLAND) 2022; 22:8955. [PMID: 36433550 PMCID: PMC9693484 DOI: 10.3390/s22228955] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Revised: 11/11/2022] [Accepted: 11/17/2022] [Indexed: 06/16/2023]
Abstract
Centrifugal microfluidic platforms (CDs) have opened new possibilities for inexpensive point-of-care (POC) diagnostics. They are now widely used in applications requiring polymerase chain reaction steps, blood plasma separation, serial dilutions, and many other diagnostic processes. CD microfluidic devices allow a variety of complex processes to transfer onto the small disc platform that previously were carried out by individual expensive laboratory equipment requiring trained personnel. The portability, ease of operation, integration, and robustness of the CD fluidic platforms requires simple, reliable, and scalable designs to control the flow of fluids. Valves play a vital role in opening/closing of microfluidic channels to enable a precise control of the flow of fluids on a centrifugal platform. Valving systems are also critical in isolating chambers from the rest of a fluidic network at required times, in effectively directing the reagents to the target location, in serial dilutions, and in integration of multiple other processes on a single CD. In this paper, we review the various available fluidic valving systems, discuss their working principles, and evaluate their compatibility with CD fluidic platforms. We categorize the presented valving systems into either "active", "passive", or "hybrid"-based on their actuation mechanism that can be mechanical, thermal, hydrophobic/hydrophilic, solubility-based, phase-change, and others. Important topics such as their actuation mechanism, governing physics, variability of performance, necessary disc spin rate for valve actuation, valve response time, and other parameters are discussed. The applicability of some types of valves for specialized functions such as reagent storage, flow control, and other applications is summarized.
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Affiliation(s)
- Snehan Peshin
- Department of Mechanical and Aerospace Engineering, University of California, Irvine, CA 92697, USA
| | - Marc Madou
- Department of Mechanical and Aerospace Engineering, University of California, Irvine, CA 92697, USA
- School of Engineering and Science, Tecnológico de Monterrey, Monterrey 64849, Mexico
| | - Lawrence Kulinsky
- Department of Mechanical and Aerospace Engineering, University of California, Irvine, CA 92697, USA
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6
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Enhanced liquid retention capacity within plastic food packaging through modified capillary recesses. J FOOD ENG 2022. [DOI: 10.1016/j.jfoodeng.2022.111010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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7
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Lin YT, Huang CS, Tseng SC. How to Control the Microfluidic Flow and Separate the Magnetic and Non-Magnetic Particles in the Runner of a Disc. MICROMACHINES 2021; 12:mi12111335. [PMID: 34832747 PMCID: PMC8625270 DOI: 10.3390/mi12111335] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/02/2021] [Revised: 10/23/2021] [Accepted: 10/28/2021] [Indexed: 12/14/2022]
Abstract
Biochips play an important role in both medical and food industry safety testing. Moreover, magnetic activated cell sorting is a well-established technology for biochip development. However, biochips need to be manufactured by precision instruments, resulting in the high cost of biochips. Therefore, this study used magnetic-activation and mechanics theories to create a novel disc that could manipulate the microfluidic flow, mixing, reaction, and separation on the runner of the disc. The goal of the research was to apply in the field of biomedical detection systems to reduce the cost of biochips and simplify the operation process. The simulation and experimental investigation showed that the pattern of the reaction chamber was stomach-shaped and the reservoir chamber was rectangular-shaped on the disc. The microfluid could be controlled to flow to the reaction chamber from the buffer and sample chamber when the disc spun at 175~200 rpm within three minutes. This was defined as the first setting mode. The microfluid could then be controlled to flow to the reservoir chamber from the reaction chamber when the disc spun at 225 rpm within five to ten minutes. This was defined as the second setting mode. This verified that the pattern design of the disc was optimized for control of the microfluid flow, mixing, reaction, and separation in the runner of the disc by different setting modes.
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Affiliation(s)
- Yao-Tsung Lin
- Department of Mechanical Engineering, Chien Hsin University of Science and Technology, Zhongli District, Taoyuan 320312, Taiwan;
| | - Chien-Sheng Huang
- Department of Electronic Engineering, National Yunlin University of Science and Technology, Douliu, Yunlin 64002, Taiwan
- Correspondence:
| | - Shi-Chang Tseng
- Department of Mechanical Engineering, National Yunlin University of Science and Technology, Douliu, Yunlin 64002, Taiwan;
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8
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Separation of human granulocytes and mononuclear cells from whole blood using percoll on a centrifugal microfluidic disc. Microchem J 2021. [DOI: 10.1016/j.microc.2021.106316] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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9
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Dignan LM, Woolf MS, Tomley CJ, Nauman AQ, Landers JP. Multiplexed Centrifugal Microfluidic System for Dynamic Solid-Phase Purification of Polynucleic Acids Direct from Buccal Swabs. Anal Chem 2021; 93:7300-7309. [PMID: 33955733 DOI: 10.1021/acs.analchem.1c00842] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
This report describes the development of a centrifugally controlled microfluidic dynamic solid-phase extraction (dSPE) platform to reliably obtain amplification-ready nucleic acids (NAs) directly from buccal swab cuttings. To our knowledge, this work represents the first centrifugal microdevice for comprehensive preparation of high-purity NAs from raw buccal swab samples. Direct-from-swab cellular lysis was integrated upstream of NA extraction, and automatable laser-controlled on-board microvalving strategies provided the strict spatiotemporal fluidic control required for practical point-of-need use. Solid-phase manipulation during extraction leveraged the application of a bidirectional rotating magnetic field to promote thorough interaction with the sample (e.g., NA capture). We illustrate the broad utility of this technology by establishing downstream compatibility of extracted nucleic acids with three noteworthy assays, namely, the polymerase chain reaction (PCR), reverse transcriptase PCR (RT-qPCR), and loop-mediated isothermal amplification (LAMP). The PCR-readiness of the extracted DNA was confirmed by generating short tandem repeat (STR) profiles following multiplexed amplification. With no changes to assay workflow, viral RNA was successfully extracted from contrived (spiked) SARS-CoV-2 swab samples, confirmed by RT-qPCR. Finally, we demonstrate the compatibility of the extracted DNA with LAMP-a technique well suited for point-of-need genetic analysis due to minimal hardware requirements and compatibility with colorimetric readout. We describe an automatable, portable microfluidic platform for the nucleic acid preparation device that could permit practical, in situ use by nontechnical personnel.
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Affiliation(s)
- Leah M Dignan
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904, United States
| | - M Shane Woolf
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904, United States
| | - Christopher J Tomley
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904, United States
| | - Aeren Q Nauman
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904, United States.,TeGrex Technologies, Charlottesville, Virginia 22903, United States
| | - James P Landers
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904, United States
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10
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El-Tholoth M, Bai H, Mauk MG, Saif L, Bau HH. A portable, 3D printed, microfluidic device for multiplexed, real time, molecular detection of the porcine epidemic diarrhea virus, transmissible gastroenteritis virus, and porcine deltacoronavirus at the point of need. LAB ON A CHIP 2021; 21:1118-1130. [PMID: 33527920 PMCID: PMC7990716 DOI: 10.1039/d0lc01229g] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The porcine epidemic diarrhea virus (PEDV), transmissible gastroenteritis virus (TGEV), and porcine deltacoronavirus (PDCoV) are emerging/reemerging coronaviruses (CoVs) of neonatal pigs that cause great economic losses to pig farms and pork processors. Specific, rapid, and simple multiplex detection of these viruses is critical to enable prompt implementation of appropriate control measures. Conventional methods for molecular diagnosis require skilled personnel and relatively sophisticated equipment, restricting their use in centralized laboratories. We developed a low-cost, rapid, semi-quantitative, field deployable, 3D-printed microfluidic device for auto-distribution of samples and self-sealing and real-time and reverse transcription-loop-mediated isothermal amplification (RT-LAMP), enabling the co-detection of PEDV, TGEV and PDCoV within 30 minutes. Our assay's analytical performance is comparable with a benchtop, real-time RT-LAMP assay and the gold standard quantitative reverse transcription-polymerase chain reaction (qRT-PCR) assay with limits of detection of 10 genomic copies per reaction for PEDV and PDCoV, and 100 genomic copies per reaction for TGEV. Evaluation of clinical specimens from diseased pigs with our microfluidic device revealed excellent concordance with both benchtop RT-LAMP and qRT-PCR. Our portable RT-LAMP microfluidic chip will potentially facilitate simple, specific, rapid multiplexed detection of harmful infections in minimally equipped veterinary diagnostic laboratories and on-site in pigs' farms.
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Affiliation(s)
- Mohamed El-Tholoth
- Department of Virology, Faculty of Veterinary Medicine, Mansoura University, Mansoura 35516, Egypt.
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11
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de Oliveira KG, Estrela PFN, Mendes GDM, Dos Santos CA, Silveira-Lacerda EDP, Duarte GRM. Rapid molecular diagnostics of COVID-19 by RT-LAMP in a centrifugal polystyrene-toner based microdevice with end-point visual detection. Analyst 2021; 146:1178-1187. [PMID: 33439160 DOI: 10.1039/d0an02066d] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Infection caused by the new coronavirus (SARS-CoV-2) has become a serious worldwide public health problem, and one of the most important strategies for its control is mass testing. Loop-mediated isothermal amplification (LAMP) has emerged as an important alternative to simplify the diagnostics of infectious diseases. In addition, an advantage of LAMP is that it allows for easy reading of the final result through visual detection. However, this step must be performed with caution to avoid contamination and false-positive results. LAMP performed on microfluidic platforms can minimize false-positive results, in addition to having potential for point-of-care applications. Here, we describe a polystyrene-toner (PS-T) centrifugal microfluidic device manually controlled by a fidget spinner for molecular diagnosis of COVID-19 by RT-LAMP, with integrated and automated colorimetric detection. The amplification was carried out in a microchamber with 5 μL capacity, and the reaction was thermally controlled with a thermoblock at 72 °C for 10 min. At the end of the incubation time, the detection of amplified RT-LAMP fragments was performed directly on the chip by automated visual detection. Our results demonstrate that it is possible to detect COVID-19 in reactions initiated with approximately 10-3 copies of SARS-CoV-2 RNA. Clinical samples were tested using our RT-LAMP protocol as well as by conventional RT-qPCR, demonstrating comparable performance to the CDC SARS-CoV-2 RT-qPCR assay. The methodology described in this study represents a simple, rapid, and accurate method for rapid molecular diagnostics of COVID-19 in a disposable microdevice, ideal for point-of-care testing (POCT) systems.
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12
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Study on Electrical Performance of a U-Type Microfluidic Acceleration Switch Using Salt Solution as the Sensitive Electrode. SENSORS 2020; 20:s20247062. [PMID: 33321709 PMCID: PMC7764254 DOI: 10.3390/s20247062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Revised: 12/02/2020] [Accepted: 12/04/2020] [Indexed: 11/29/2022]
Abstract
The threshold of microfluidic inertial switch is excessively dependent on the size of the passive valve structure and the gas–liquid surface energy of working liquid. How to achieve high threshold and anti-high overload using liquid with low viscosity and low surface tension is a challenging work. Based on the designed U-type microfluidic inertial switch, the electrical characteristic of salt solution at microscale as well as the threshold and dynamic electrical performance of switch were studied. The VOF and CSD modules in CFD software were employed to analyze the dynamic flow process, and then the air–liquid surface moving displacement curve was compared by the theoretical model. A self-designed acceleration test platform was utilized to measure the static threshold, dynamic threshold, and anti-high overload of the inertial switch. The results show that the U-type microfluidics inertial switch using salt solution as sensitive electrode has better performance in power connection and anti-high overload. In particular, it also has the ability to achieve a range of dynamic threshold by changing the placement of the contact electrode, which can achieve rapid power on and off.
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13
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Hess JF, Zehnle S, Juelg P, Hutzenlaub T, Zengerle R, Paust N. Review on pneumatic operations in centrifugal microfluidics. LAB ON A CHIP 2019; 19:3745-3770. [PMID: 31596297 DOI: 10.1039/c9lc00441f] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Centrifugal microfluidics allows for miniaturization, automation and parallelization of laboratory workflows. The fact that centrifugal forces are always directed radially outwards has been considered a main drawback for the implementation of complex workflows leading to the requirement of additional actuation forces for pumping, valving and switching. In this work, we review and discuss the combination of centrifugal with pneumatic forces which enables transport of even complex liquids in any direction on centrifugal systems, provides actuation for valving and switching, offers alternatives for mixing and enables accurate and precise metering and aliquoting. In addition, pneumatics can be employed for timing to carry out any of the above listed unit operations in a sequential and cascaded manner. Firstly, different methods to generate pneumatic pressures are discussed. Then, unit operations and applications that employ pneumatics are reviewed. Finally, a tutorial section discusses two examples to provide insight into the design process. The first tutorial explains a comparatively simple implementation of a pneumatic siphon valve and provides a workflow to derive optimum design parameters. The second tutorial discusses cascaded pneumatic operations consisting of temperature change rate actuated valving and subsequent pneumatic pumping. In conclusion, combining pneumatic actuation with centrifugal microfluidics allows for the design of robust fluidic networks with simple fluidic structures that are implemented in a monolithic fashion. No coatings are required and the overall demands on manufacturing are comparatively low. We see the combination of centrifugal forces with pneumatic actuation as a key enabling technology to facilitate compact and robust automation of biochemical analysis.
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Affiliation(s)
- J F Hess
- Laboratory for MEMS Applications, Department of Microsystems Engineering - IMTEK, University of Freiburg, Georges-Koehler-Allee 103, 79110 Freiburg, Germany
| | - S Zehnle
- Hahn-Schickard, Georges-Koehler-Allee 103, 79110 Freiburg, Germany.
| | - P Juelg
- Hahn-Schickard, Georges-Koehler-Allee 103, 79110 Freiburg, Germany.
| | - T Hutzenlaub
- Laboratory for MEMS Applications, Department of Microsystems Engineering - IMTEK, University of Freiburg, Georges-Koehler-Allee 103, 79110 Freiburg, Germany and Hahn-Schickard, Georges-Koehler-Allee 103, 79110 Freiburg, Germany.
| | - R Zengerle
- Laboratory for MEMS Applications, Department of Microsystems Engineering - IMTEK, University of Freiburg, Georges-Koehler-Allee 103, 79110 Freiburg, Germany and Hahn-Schickard, Georges-Koehler-Allee 103, 79110 Freiburg, Germany.
| | - N Paust
- Laboratory for MEMS Applications, Department of Microsystems Engineering - IMTEK, University of Freiburg, Georges-Koehler-Allee 103, 79110 Freiburg, Germany and Hahn-Schickard, Georges-Koehler-Allee 103, 79110 Freiburg, Germany.
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14
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Chen YW, Li WT, Chang Y, Lee RH, Hsiue GH. Blood-typing and irregular antibody screening through multi-channel microfluidic discs with surface antifouling modification. BIOMICROFLUIDICS 2019; 13:034107. [PMID: 31123539 PMCID: PMC6513751 DOI: 10.1063/1.5080463] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Accepted: 04/29/2019] [Indexed: 06/09/2023]
Abstract
A novel surface modification technology for microfluidic disks was developed for multichannel blood-typing detection and irregular antibody screening. The antifouling material, poly(ethylene glycol) methacrylate (PEGMA), was used to modify the surface of the microfluidic disk for improving its hydrophilicity and blood compatibility. With the modification of PEGMA, the hydrophilicity was sufficiently improved with a 44.5% reduction of water contact angle. The modified microfluidic disk also showed good biocompatibility with a reduction of hemolytic index (from 3.4% to 1.2%) and platelet adhesion (from 4.6 × 104/cm2 to 1.9 × 104/cm2). Furthermore, the PEGMA modification technique conducted on the microfluidic disk achieved successful adjustment of burst frequency for each chamber in the microchannel, allowing a sequential addiction of reagents in the test protocol of manual polybrene (MP) blood typing. Clinical studies showed that the proposed MP microfluidic disk method not only performed at extremely high consistency with the traditional tube method in the identification of ABO/RhD blood types, but also accomplished an effective screening method for detecting irregular antibodies. In conclusion, this study demonstrated that the easily mass-produced MP microfluidic disk exhibited good blood-typing sensitivity and was suitable for clinical applications.
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Affiliation(s)
- Yan-Wen Chen
- Department of Chemical Engineering, National Chung Hsing University, Taichung 402, Taiwan
| | - Wen-Tyng Li
- Department of Biomedical Engineering, Center for Nanotechnology, Chung Yuan Christian University, Chung-Li,
Taoyuan 320, Taiwan
| | - Yung Chang
- Chung Yuan Christian University, Chung-Li, Taoyuan 320, Taiwan
| | - Rong-Ho Lee
- Department of Chemical Engineering, National Chung Hsing University, Taichung 402, Taiwan
| | - Ging-Ho Hsiue
- Authors to whom correspondence should be addressed:and
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15
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Miyazaki CM, Kinahan DJ, Mishra R, Mangwanya F, Kilcawley N, Ferreira M, Ducrée J. Label-free, spatially multiplexed SPR detection of immunoassays on a highly integrated centrifugal Lab-on-a-Disc platform. Biosens Bioelectron 2018; 119:86-93. [PMID: 30103158 DOI: 10.1016/j.bios.2018.07.056] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Revised: 07/18/2018] [Accepted: 07/27/2018] [Indexed: 02/06/2023]
Abstract
As a direct, label-free method, Surface Plasmon Resonance (SPR) detection significantly reduces the needs for liquid handling and reagent storage compared to common enzyme-linked immunosorbent assays (ELISAs), thus enabling comprehensive multiplexing of bioassays on microfluidic sample-to-answer systems. This paper describes a highly integrated centrifugal Lab-on-a-Disc (LoaD) platform for automating the full process chain extending between plasma extraction and subsequent aliquoting to five parallelized reaction channels for quantitative SPR detection by an inexpensive smartphone camera. The entire, multi-step / multi-reagent operation completes within less than 1 h. While the emphasis of this work is on the fluidic automation and parallelization by previously introduced, very robust event-triggered valving and buoyancy-driven centripetal pumping schemes, we successfully implement an immunoglobulin G (IgG) assay; by specific functionalization of the detection surfaces, the same disc layout can readily be customised for immunoassays panels from whole blood.
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Affiliation(s)
- Celina M Miyazaki
- FPC@DCU - Fraunhofer Project Centre for Embedded Bioanalytical Systems at Dublin City University, School of Physical Sciences, Dublin City University, Ireland; Federal University of São Carlos, Sorocaba, SP, Brazil.
| | - David J Kinahan
- FPC@DCU - Fraunhofer Project Centre for Embedded Bioanalytical Systems at Dublin City University, School of Physical Sciences, Dublin City University, Ireland
| | - Rohit Mishra
- FPC@DCU - Fraunhofer Project Centre for Embedded Bioanalytical Systems at Dublin City University, School of Physical Sciences, Dublin City University, Ireland
| | - Faith Mangwanya
- FPC@DCU - Fraunhofer Project Centre for Embedded Bioanalytical Systems at Dublin City University, School of Physical Sciences, Dublin City University, Ireland
| | - Niamh Kilcawley
- FPC@DCU - Fraunhofer Project Centre for Embedded Bioanalytical Systems at Dublin City University, School of Physical Sciences, Dublin City University, Ireland
| | | | - Jens Ducrée
- FPC@DCU - Fraunhofer Project Centre for Embedded Bioanalytical Systems at Dublin City University, School of Physical Sciences, Dublin City University, Ireland.
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16
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Abd Rahman N, Ibrahim F, Aeinehvand MM, Yusof R, Madou M. A Microfluidic Lab-on-a-Disc (LOD) for Antioxidant Activities of Plant Extracts. MICROMACHINES 2018; 9:E140. [PMID: 30424074 PMCID: PMC6187507 DOI: 10.3390/mi9040140] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/13/2018] [Revised: 03/15/2018] [Accepted: 03/19/2018] [Indexed: 11/25/2022]
Abstract
Antioxidants are an important substance that can fight the deterioration of free radicals and can easily oxidize when exposed to light. There are many methods to measure the antioxidant activity in a biological sample, for example 2,2-diphenyl-1-picrylhydrazyl (DPPH) antioxidant activity test, which is one of the simplest methods used. Despite its simplicity, the organic solvent that has been used to dilute DPPH is easily evaporated and degraded with respect to light exposure and time. Thus, it needs to be used at the earliest convenient time prior to the experiment. To overcome this issue, a rapid and close system for antioxidant activity is required. In this paper, we introduced the Lab-on-a-Disc (LoD) method that integrates the DPPH antioxidant activity test on a microfluidic compact disc (CD). We used ascorbic acid, quercetin, Areca catechu, Polygonum minus, and Syzygium polyanthum plant extracts to compare the results of our proposed LoD method with the conventional method. Contrasted to the arduous laborious conventional method, our proposed method offer rapid analysis and simple determination of antioxidant. This proposed LoD method for antioxidant activity in plants would be a platform for the further development of antioxidant assay.
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Affiliation(s)
- Nurhaslina Abd Rahman
- Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia.
- Centre for Innovation in Medical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia.
| | - Fatimah Ibrahim
- Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia.
- Centre for Innovation in Medical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia.
| | - Mohammad M Aeinehvand
- Centre for Innovation in Medical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia.
- School of Engineering and Sciences, Tecnologico de Monterrey, Av. Eugenio Garza Sada 2501 Sur, 64849 Monterrey, NL, Mexico.
| | - Rohana Yusof
- Department of Molecular Medicine, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia.
| | - Marc Madou
- Centre for Innovation in Medical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia.
- Department of Biomedical Engineering, University of California, Irvine, CA 92697, USA.
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17
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Torres Delgado SM, Kinahan DJ, Nirupa Julius LA, Mallette A, Ardila DS, Mishra R, Miyazaki CM, Korvink JG, Ducrée J, Mager D. Wirelessly powered and remotely controlled valve-array for highly multiplexed analytical assay automation on a centrifugal microfluidic platform. Biosens Bioelectron 2018; 109:214-223. [PMID: 29567566 DOI: 10.1016/j.bios.2018.03.012] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Revised: 02/09/2018] [Accepted: 03/06/2018] [Indexed: 12/14/2022]
Abstract
In this paper we present a wirelessly powered array of 128 centrifugo-pneumatic valves that can be thermally actuated on demand during spinning. The valves can either be triggered by a predefined protocol, wireless signal transmission via Bluetooth, or in response to a sensor monitoring a parameter like the temperature, or homogeneity of the dispersion. Upon activation of a resistive heater, a low-melting membrane (Parafilm™) is removed to vent an entrapped gas pocket, thus letting the incoming liquid wet an intermediate dissolvable film and thereby open the valve. The proposed system allows up to 12 heaters to be activated in parallel, with a response time below 3 s, potentially resulting in 128 actuated valves in under 30 s. We demonstrate, with three examples of common and standard procedures, how the proposed technology could become a powerful tool for implementing diagnostic assays on Lab-on-a-Disc. First, we implement wireless actuation of 64 valves during rotation in a freely programmable sequence, or upon user input in real time. Then, we show a closed-loop centrifugal flow control sequence for which the state of mixing of reagents, evaluated from stroboscopically recorded images, triggers the opening of the valves. In our last experiment, valving and closed-loop control are used to facilitate centrifugal processing of whole blood.
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Affiliation(s)
- Saraí M Torres Delgado
- Laboratory for Simulation, Department of Microsystems Engineering (IMTEK), University of Freiburg, Georges-Koehler-Allee 103, Freiburg im Breisgau 79110, Germany; Institute of Microstructure Technology, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, Eggenstein-Leopoldshafen 76344, Germany
| | - David J Kinahan
- FPC@DCU - Fraunhofer Project Centre for Embedded Bioanalytical Systems at Dublin City University, Glasnevin, Dublin 9, Ireland.
| | - Lourdes Albina Nirupa Julius
- FPC@DCU - Fraunhofer Project Centre for Embedded Bioanalytical Systems at Dublin City University, Glasnevin, Dublin 9, Ireland
| | - Adam Mallette
- FPC@DCU - Fraunhofer Project Centre for Embedded Bioanalytical Systems at Dublin City University, Glasnevin, Dublin 9, Ireland; Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, IN, United States
| | - David Sáenz Ardila
- Laboratory for Simulation, Department of Microsystems Engineering (IMTEK), University of Freiburg, Georges-Koehler-Allee 103, Freiburg im Breisgau 79110, Germany
| | - Rohit Mishra
- FPC@DCU - Fraunhofer Project Centre for Embedded Bioanalytical Systems at Dublin City University, Glasnevin, Dublin 9, Ireland
| | - Celina M Miyazaki
- FPC@DCU - Fraunhofer Project Centre for Embedded Bioanalytical Systems at Dublin City University, Glasnevin, Dublin 9, Ireland; Science and Technology Centre for Sustainability, Federal University of São Carlos, Campus Sorocaba, SP, Brazil
| | - Jan G Korvink
- Institute of Microstructure Technology, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, Eggenstein-Leopoldshafen 76344, Germany
| | - Jens Ducrée
- FPC@DCU - Fraunhofer Project Centre for Embedded Bioanalytical Systems at Dublin City University, Glasnevin, Dublin 9, Ireland
| | - Dario Mager
- Institute of Microstructure Technology, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, Eggenstein-Leopoldshafen 76344, Germany
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18
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Bhattacharjee N, Horowitz LF, Folch A. Continuous-flow multi-pulse electroporation at low DC voltages by microfluidic flipping of the voltage space topology. APPLIED PHYSICS LETTERS 2016; 109:163702. [PMID: 27821874 PMCID: PMC5075000 DOI: 10.1063/1.4963316] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2016] [Accepted: 09/12/2016] [Indexed: 05/13/2023]
Abstract
Concerns over biosafety, cost, and carrying capacity of viral vectors have accelerated research into physical techniques for gene delivery such as electroporation and mechanoporation. Advances in microfabrication have made it possible to create high electric fields over microscales, resulting in more efficient DNA delivery and higher cell viability. Continuous-flow microfluidic methods are typically more suitable for cellular therapies where a large number of cells need to be transfected under sterile conditions. However, the existing continuous-flow designs used to generate multiple pulses either require expensive peripherals such as high-voltage (>400 V) sources or function generators, or result in reduced cell viability due to the proximity of the cells to the electrodes. In this paper, we report a continuous-flow microfluidic device whose channel geometry reduces instrumentation demands and minimizes cellular toxicity. Our design can generate multiple pulses of high DC electric field strength using significantly lower voltages (15-60 V) than previous designs. The cells flow along a serpentine channel that repeatedly flips the cells between a cathode and an anode at high throughput. The cells must flow through a constriction each time they pass from an anode to a cathode, exposing them to high electric field strength for short durations of time (the "pulse-width"). A conductive biocompatible poly-aniline hydrogel network formed in situ is used to apply the DC voltage without bringing the metal electrodes close to the cells, further sheltering cells from the already low voltage electrodes. The device was used to electroporate multiple cell lines using electric field strengths between 700 and 800 V/cm with transfection efficiencies superior than previous flow-through designs.
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Affiliation(s)
- N Bhattacharjee
- Department of Bioengineering, University of Washington , Seattle, Washington 98195, USA
| | - L F Horowitz
- Department of Bioengineering, University of Washington , Seattle, Washington 98195, USA
| | - A Folch
- Department of Bioengineering, University of Washington , Seattle, Washington 98195, USA
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19
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Kinahan DJ, Renou M, Kurzbuch D, Kilcawley NA, Bailey É, Glynn MT, McDonagh C, Ducrée J. Baking Powder Actuated Centrifugo-Pneumatic Valving for Automation of Multi-Step Bioassays. MICROMACHINES 2016; 7:E175. [PMID: 30404349 PMCID: PMC6189914 DOI: 10.3390/mi7100175] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Revised: 09/04/2016] [Accepted: 09/19/2016] [Indexed: 01/01/2023]
Abstract
We report a new flow control method for centrifugal microfluidic systems; CO₂ is released from on-board stored baking powder upon contact with an ancillary liquid. The elevated pressure generated drives the sample into a dead-end pneumatic chamber sealed by a dissolvable film (DF). This liquid incursion wets and dissolves the DF, thus opening the valve. The activation pressure of the DF valve can be tuned by the geometry of the channel upstream of the DF membrane. Through pneumatic coupling with properly dimensioned disc architecture, we established serial cascading of valves, even at a constant spin rate. Similarly, we demonstrate sequential actuation of valves by dividing the disc into a number of distinct pneumatic chambers (separated by DF membranes). Opening these DFs, typically through arrival of a liquid to that location on a disc, permits pressurization of these chambers. This barrier-based scheme provides robust and strictly ordered valve actuation, which is demonstrated by the automation of a multi-step/multi-reagent DNA-based hybridization assay.
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Affiliation(s)
- David J Kinahan
- School of Physical Sciences, Dublin City University, Glasnevin, Dublin 9, Ireland.
- Biomedical Diagnostics Institute, Dublin City University, Glasnevin, Dublin 9, Ireland.
| | - Marine Renou
- School of Physical Sciences, Dublin City University, Glasnevin, Dublin 9, Ireland.
- Biomedical Diagnostics Institute, Dublin City University, Glasnevin, Dublin 9, Ireland.
- Telecom Physique Strasbourg, Université de Strasbourg, Strasboug CS 10413, France.
| | - Dirk Kurzbuch
- School of Physical Sciences, Dublin City University, Glasnevin, Dublin 9, Ireland.
- Biomedical Diagnostics Institute, Dublin City University, Glasnevin, Dublin 9, Ireland.
| | - Niamh A Kilcawley
- School of Physical Sciences, Dublin City University, Glasnevin, Dublin 9, Ireland.
- Biomedical Diagnostics Institute, Dublin City University, Glasnevin, Dublin 9, Ireland.
| | - Éanna Bailey
- School of Physical Sciences, Dublin City University, Glasnevin, Dublin 9, Ireland.
- Biomedical Diagnostics Institute, Dublin City University, Glasnevin, Dublin 9, Ireland.
| | - Macdara T Glynn
- School of Physical Sciences, Dublin City University, Glasnevin, Dublin 9, Ireland.
- Biomedical Diagnostics Institute, Dublin City University, Glasnevin, Dublin 9, Ireland.
| | - Colette McDonagh
- School of Physical Sciences, Dublin City University, Glasnevin, Dublin 9, Ireland.
- Biomedical Diagnostics Institute, Dublin City University, Glasnevin, Dublin 9, Ireland.
| | - Jens Ducrée
- School of Physical Sciences, Dublin City University, Glasnevin, Dublin 9, Ireland.
- Biomedical Diagnostics Institute, Dublin City University, Glasnevin, Dublin 9, Ireland.
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20
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Sposito A, Hoang V, DeVoe DL. Rapid real-time PCR and high resolution melt analysis in a self-filling thermoplastic chip. LAB ON A CHIP 2016; 16:3524-31. [PMID: 27460504 DOI: 10.1039/c6lc00711b] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
A microfluidic platform designed for point-of-care PCR-based nucleic acid diagnostics is described. Compared to established microfluidic PCR technologies, the system is unique in its ability to achieve exceptionally rapid PCR amplification in a low cost thermoplastic format, together with high temperature accuracy enabling effective validation of reaction product by high resolution melt analysis performed in the same chamber as PCR. In addition, the system employs capillary pumping for automated loading of sample into the reaction chamber, combined with an integrated hydrophilic valve for precise self-metering of sample volumes into the device. Using the microfluidic system to target a mutation in the G6PC gene, efficient PCR from human genomic DNA template is achieved with cycle times as low as 14 s, full amplification in 8.5 min, and final melt analysis accurately identifying the desired amplicon.
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Affiliation(s)
- A Sposito
- Department of Mechanical Engineering, University of Maryland, College Park, MD, USA.
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21
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Kong LX, Perebikovsky A, Moebius J, Kulinsky L, Madou M. Lab-on-a-CD. ACTA ACUST UNITED AC 2016; 21:323-55. [DOI: 10.1177/2211068215588456] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Indexed: 12/14/2022]
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22
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Density-Gradient Mediated Band Extraction of Leukocytes from Whole Blood Using Centrifugo-Pneumatic Siphon Valving on Centrifugal Microfluidic Discs. PLoS One 2016; 11:e0155545. [PMID: 27167376 PMCID: PMC4864222 DOI: 10.1371/journal.pone.0155545] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Accepted: 04/30/2016] [Indexed: 12/15/2022] Open
Abstract
Here we present retrieval of Peripheral Blood Mononuclear Cells by density-gradient medium based centrifugation for subsequent analysis of the leukocytes on an integrated microfluidic “Lab-on-a-Disc” cartridge. Isolation of white blood cells constitutes a critical sample preparation step for many bioassays. Centrifugo-pneumatic siphon valves are particularly suited for blood processing as they function without need of surface treatment and are ‘low-pass’, i.e., holding at high centrifugation speeds and opening upon reduction of the spin rate. Both ‘hydrostatically’ and ‘hydrodynamically’ triggered centrifugo-pneumatic siphon valving schemes are presented. Firstly, the geometry of the pneumatic chamber of hydrostatically primed centrifugo-pneumatic siphon valves is optimised to enable smooth and uniform layering of blood on top of the density-gradient medium; this feature proves to be key for efficient Peripheral Blood Mononuclear Cell extraction. A theoretical analysis of hydrostatically primed valves is also presented which determines the optimum priming pressure for the individual valves. Next, ‘dual siphon’ configurations for both hydrostatically and hydrodynamically primed centrifugo-pneumatic siphon valves are introduced; here plasma and Peripheral Blood Mononuclear Cells are extracted through a distinct siphon valve. This work represents a first step towards enabling on disc multi-parameter analysis. Finally, the efficiency of Peripheral Blood Mononuclear Cells extraction in these structures is characterised using a simplified design. A microfluidic mechanism, which we termed phase switching, is identified which affects the efficiency of Peripheral Blood Mononuclear Cell extraction.
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23
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Al-Faqheri W, Ibrahim F, Thio THG, Joseph K, Mohktar MS, Madou M. Liquid density effect on burst frequency in centrifugal microfluidic platforms. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2016; 2015:3221-4. [PMID: 26736978 DOI: 10.1109/embc.2015.7319078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Centrifugal microfluidic platforms are widely used in various advanced processes such as biomedical diagnostics, chemical analysis and drug screening. This paper investigates the effect of liquid density on the burst frequency of the centrifugal microfluidic platform. This effect is experimentally investigated and compared to theoretical values. It is found that increasing the liquid density results in lower burst frequency and it is in agreement with theoretical calculations. Moreover, in this study we proposed the use of the microfluidic CD platform as an inexpensive and simple sensor for liquid density measurements. The proposed liquid sensor requires much less liquid volume (in the range of microliters) compared to conventional density meters. This study presents fundamental work which allows for future advance studies with the aim of designing and fabricating centrifugal microfluidic platforms for more complex tasks such as blood analysis.
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24
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A Colorimetric Enzyme-Linked Immunosorbent Assay (ELISA) Detection Platform for a Point-of-Care Dengue Detection System on a Lab-on-Compact-Disc. SENSORS 2015; 15:11431-41. [PMID: 25993517 PMCID: PMC4481904 DOI: 10.3390/s150511431] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/15/2014] [Accepted: 03/18/2015] [Indexed: 11/17/2022]
Abstract
The enzyme-linked Immunosorbent Assay (ELISA) is the gold standard clinical diagnostic tool for the detection and quantification of protein biomarkers. However, conventional ELISA tests have drawbacks in their requirement of time, expensive equipment and expertise for operation. Hence, for the purpose of rapid, high throughput screening and point-of-care diagnosis, researchers are miniaturizing sandwich ELISA procedures on Lab-on-a-Chip and Lab-on-Compact Disc (LOCD) platforms. This paper presents a novel integrated device to detect and interpret the ELISA test results on a LOCD platform. The system applies absorption spectrophotometry to measure the absorbance (optical density) of the sample using a monochromatic light source and optical sensor. The device performs automated analysis of the results and presents absorbance values and diagnostic test results via a graphical display or via Bluetooth to a smartphone platform which also acts as controller of the device. The efficacy of the device was evaluated by performing dengue antibody IgG ELISA on 64 hospitalized patients suspected of dengue. The results demonstrate high accuracy of the device, with 95% sensitivity and 100% specificity in detection when compared with gold standard commercial ELISA microplate readers. This sensor platform represents a significant step towards establishing ELISA as a rapid, inexpensive and automatic testing method for the purpose of point-of-care-testing (POCT) in resource-limited settings.
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25
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Thio THG, Ibrahim F, Al-Faqheri W, Soin N, Kahar Bador M, Madou M. Sequential push-pull pumping mechanism for washing and evacuation of an immunoassay reaction chamber on a microfluidic CD platform. PLoS One 2015; 10:e0121836. [PMID: 25853411 PMCID: PMC4390340 DOI: 10.1371/journal.pone.0121836] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2014] [Accepted: 02/18/2015] [Indexed: 11/23/2022] Open
Abstract
A centrifugal compact disc (CD) microfluidic platform with reservoirs, micro-channels, and valves can be employed for implementing a complete immunoassay. Detection or biosensor chambers are either coated for immuno-interaction or a biosensor chip is inserted in them. On microfluidic CDs featuring such multi-step chemical/biological processes, the biosensor chamber must be repeatedly filled with fluids such as enzymes solutions, buffers, and washing solutions. After each filling step, the biosensor chamber needs to be evacuated by a passive siphoning process to prepare it for the next step in the assay. However, rotational speed dependency and limited space on a CD are two big obstacles to performing such repetitive filling and siphoning steps. In this work, a unique thermo-pneumatic (TP) Push-Pull pumping method is employed to provide a superior alternative biosensor chamber filling and evacuation technique. The proposed technique is demonstrated on two CD designs. The first design features a simple two-step microfluidic process to demonstrate the evacuation technique, while the second design shows the filling and evacuation technique with an example sequence for an actual immunoassay. In addition, the performance of the filling and evacuation technique as a washing step is also evaluated quantitatively and compared to the conventional manual bench top washing method. The two designs and the performance evaluation demonstrate that the technique is simple to implement, reliable, easy to control, and allows for repeated push-pulls and thus filling and emptying of the biosensor chamber. Furthermore, by addressing the issue of rotational speed dependency and limited space concerns in implementing repetitive filling and evacuation steps, this newly introduced technique increases the flexibility of the microfluidic CD platform to perform multi-step biological and chemical processes.
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Affiliation(s)
- Tzer Hwai Gilbert Thio
- Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia
- Centre for Innovation in Medical Engineering, Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia
- Faculty of Science, Technology, Engineering and Mathematics, INTI International University, Persiaran Perdana BBN, Putra Nilai, 71800 Nilai, Negeri Sembilan, Malaysia
| | - Fatimah Ibrahim
- Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia
- Centre for Innovation in Medical Engineering, Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia
- * E-mail:
| | - Wisam Al-Faqheri
- Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia
- Centre for Innovation in Medical Engineering, Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - Norhayati Soin
- Centre for Innovation in Medical Engineering, Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia
- Department of Electrical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - Maria Kahar Bador
- Centre for Innovation in Medical Engineering, Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - Marc Madou
- Centre for Innovation in Medical Engineering, Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia
- Department of Biomedical Engineering, University of California Irvine, Irvine, 92697, California, United States of America
- Department of Mechanical and Aerospace Engineering, University of California Irvine, Irvine, 92697, California, United States of America
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26
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Ibrahim F, Thio THG, Faisal T, Neuman M. The application of biomedical engineering techniques to the diagnosis and management of tropical diseases: a review. SENSORS 2015; 15:6947-95. [PMID: 25806872 PMCID: PMC4435123 DOI: 10.3390/s150306947] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/07/2014] [Revised: 12/05/2014] [Accepted: 01/07/2015] [Indexed: 11/18/2022]
Abstract
This paper reviews a number of biomedical engineering approaches to help aid in the detection and treatment of tropical diseases such as dengue, malaria, cholera, schistosomiasis, lymphatic filariasis, ebola, leprosy, leishmaniasis, and American trypanosomiasis (Chagas). Many different forms of non-invasive approaches such as ultrasound, echocardiography and electrocardiography, bioelectrical impedance, optical detection, simplified and rapid serological tests such as lab-on-chip and micro-/nano-fluidic platforms and medical support systems such as artificial intelligence clinical support systems are discussed. The paper also reviewed the novel clinical diagnosis and management systems using artificial intelligence and bioelectrical impedance techniques for dengue clinical applications.
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Affiliation(s)
- Fatimah Ibrahim
- Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia.
- Centre for Innovation in Medical Engineering (CIME), Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia.
| | - Tzer Hwai Gilbert Thio
- Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia.
- Centre for Innovation in Medical Engineering (CIME), Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia.
- Faculty of Science, Technology, Engineering and Mathematics, INTI International University, 71800 Nilai, Negeri Sembilan, Malaysia.
| | - Tarig Faisal
- Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia.
- Centre for Innovation in Medical Engineering (CIME), Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia.
- Faculty-Electronics Engineering, Ruwais College, Higher Colleges of Technology, Ruwais, P.O Box 12389, UAE.
| | - Michael Neuman
- Department of Biomedical Engineering, Michigan Technological University, Houghton, MI 49931, USA.
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27
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Al-Faqheri W, Ibrahim F, Thio THG, Bahari N, Arof H, Rothan HA, Yusof R, Madou M. Development of a passive liquid valve (PLV) utilizing a pressure equilibrium phenomenon on the centrifugal microfluidic platform. SENSORS 2015; 15:4658-76. [PMID: 25723143 PMCID: PMC4435176 DOI: 10.3390/s150304658] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/17/2014] [Revised: 12/12/2014] [Accepted: 12/17/2014] [Indexed: 11/29/2022]
Abstract
In this paper, we propose an easy-to-implement passive liquid valve (PLV) for the microfluidic compact-disc (CD). This valve can be implemented by introducing venting chambers to control the air flow of the source and destination chambers. The PLV mechanism is based on equalizing the main forces acting on the microfluidic CD (i.e., the centrifugal and capillary forces) to control the burst frequency of the source chamber liquid. For a better understanding of the physics behind the proposed PLV, an analytical model is described. Moreover, three parameters that control the effectiveness of the proposed valve, i.e., the liquid height, liquid density, and venting chamber position with respect to the CD center, are tested experimentally. To demonstrate the ability of the proposed PLV valve, microfluidic liquid switching and liquid metering are performed. In addition, a Bradford assay is performed to measure the protein concentration and evaluated in comparison to the benchtop procedure. The result shows that the proposed valve can be implemented in any microfluidic process that requires simplicity and accuracy. Moreover, the developed valve increases the flexibility of the centrifugal CD platform for passive control of the liquid flow without the need for an external force or trigger.
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Affiliation(s)
- Wisam Al-Faqheri
- Centre for Innovation in Medical Engineering (CIME), Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia.
- Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia.
| | - Fatimah Ibrahim
- Centre for Innovation in Medical Engineering (CIME), Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia.
- Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia.
| | - Tzer Hwai Gilbert Thio
- Centre for Innovation in Medical Engineering (CIME), Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia.
- Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia.
- Faculty of Science, Technology, Engineering and Mathematics, INTI International University, Persiaran Perdana BBN, Putra Nilai, 71800 Nilai, Negeri Sembilan, Malaysia.
| | - Norulain Bahari
- Centre for Innovation in Medical Engineering (CIME), Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia.
- Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia.
| | - Hamzah Arof
- Centre for Innovation in Medical Engineering (CIME), Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia.
- Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia.
- Department of Electrical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia.
| | - Hussin A Rothan
- Department of Molecular Medicine, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia.
| | - Rohana Yusof
- Department of Molecular Medicine, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia.
| | - Marc Madou
- Centre for Innovation in Medical Engineering (CIME), Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia.
- Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia.
- Department of Biomedical Engineering, University of California, Irvine, 92697 CA, USA.
- Department of Mechanical and Aerospace Engineering, University of California, Irvine, 92697 CA, USA.
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28
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Kar S, Dash M, Maiti TK, Chakraborty S. Effect of hematocrit on blood dynamics on a compact disc platform. Analyst 2015; 140:1432-7. [PMID: 25619412 DOI: 10.1039/c4an02020k] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We investigate blood flow dynamics on a rotationally actuated lab-on-a-compact disk (LOCD) platform, as a function of the hematocrit level of the blood sample. In particular, we emphasize the resultant implications on the critical fluidic parameters, such as on burst frequency and volumetric flow rate. Our results can be utilized as a characteristic guideline to predict the hematological parameters of a given small amount of blood sample from the observed flow characteristics, and can give rise to a new paradigm of medical diagnostics driven by interactions between blood rheology and rotational forces on an inexpensive platform, with minimal sample consumption.
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Affiliation(s)
- Shantimoy Kar
- Advanced Technology Development Centre, Indian Institute of Technology Kharagpur, Kharagpur 721302, India
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29
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Kazemzadeh A, Ganesan P, Ibrahim F, Kulinsky L, Madou MJ. Guided routing on spinning microfluidic platforms. RSC Adv 2015. [DOI: 10.1039/c4ra14397c] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
A robust two stage passive microvalve is devised that can be used for (a) changing the flow direction continuously from one direction to another, and (b) liquid/particle distribution in centrifugal microfluidics.
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Affiliation(s)
- Amin Kazemzadeh
- Department of Mechanical Engineering
- Faculty of Engineering
- University of Malaya
- Kuala Lumpur
- Malaysia
| | - P. Ganesan
- Department of Mechanical Engineering
- Faculty of Engineering
- University of Malaya
- Kuala Lumpur
- Malaysia
| | - Fatimah Ibrahim
- Department of Biomedical Engineering
- Faculty of Engineering
- University of Malaya
- Kuala Lumpur
- Malaysia
| | - Lawrence Kulinsky
- Department of Biomedical Engineering
- University of California
- Irvine
- USA
| | - Marc J. Madou
- Department of Biomedical Engineering
- University of California
- Irvine
- USA
- Department of Mechanical and Aerospace Engineering
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30
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Kinahan DJ, Kearney SM, Faneuil OP, Glynn MT, Dimov N, Ducrée J. Paper imbibition for timing of multi-step liquid handling protocols on event-triggered centrifugal microfluidic lab-on-a-disc platforms. RSC Adv 2015. [DOI: 10.1039/c4ra14887h] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Imbibition of liquid along a paper strip offers enhanced flow control of dissolvable film valve on the centrifugal platform.
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Affiliation(s)
- David J. Kinahan
- Biomedical Diagnostics Institute
- National Centre of Sensor Research
- Dublin City University
- Dublin 9
- Ireland
| | - Sinéad M. Kearney
- Biomedical Diagnostics Institute
- National Centre of Sensor Research
- Dublin City University
- Dublin 9
- Ireland
| | - Olivier P. Faneuil
- Biomedical Diagnostics Institute
- National Centre of Sensor Research
- Dublin City University
- Dublin 9
- Ireland
| | - Macdara T. Glynn
- Biomedical Diagnostics Institute
- National Centre of Sensor Research
- Dublin City University
- Dublin 9
- Ireland
| | - Nikolay Dimov
- Biomedical Diagnostics Institute
- National Centre of Sensor Research
- Dublin City University
- Dublin 9
- Ireland
| | - Jens Ducrée
- Biomedical Diagnostics Institute
- National Centre of Sensor Research
- Dublin City University
- Dublin 9
- Ireland
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31
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Kinahan DJ, Kearney SM, Dimov N, Glynn MT, Ducrée J. Event-triggered logical flow control for comprehensive process integration of multi-step assays on centrifugal microfluidic platforms. LAB ON A CHIP 2014; 14:2249-58. [PMID: 24811251 DOI: 10.1039/c4lc00380b] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
The centrifugal "lab-on-a-disc" concept has proven to have great potential for process integration of bioanalytical assays, in particular where ease-of-use, ruggedness, portability, fast turn-around time and cost efficiency are of paramount importance. Yet, as all liquids residing on the disc are exposed to the same centrifugal field, an inherent challenge of these systems remains the automation of multi-step, multi-liquid sample processing and subsequent detection. In order to orchestrate the underlying bioanalytical protocols, an ample palette of rotationally and externally actuated valving schemes has been developed. While excelling with the level of flow control, externally actuated valves require interaction with peripheral instrumentation, thus compromising the conceptual simplicity of the centrifugal platform. In turn, for rotationally controlled schemes, such as common capillary burst valves, typical manufacturing tolerances tend to limit the number of consecutive laboratory unit operations (LUOs) that can be automated on a single disc. In this paper, a major advancement on recently established dissolvable film (DF) valving is presented; for the very first time, a liquid handling sequence can be controlled in response to completion of preceding liquid transfer event, i.e. completely independent of external stimulus or changes in speed of disc rotation. The basic, event-triggered valve configuration is further adapted to leverage conditional, large-scale process integration. First, we demonstrate a fluidic network on a disc encompassing 10 discrete valving steps including logical relationships such as an AND-conditional as well as serial and parallel flow control. Then we present a disc which is capable of implementing common laboratory unit operations such as metering and selective routing of flows. Finally, as a pilot study, these functions are integrated on a single disc to automate a common, multi-step lab protocol for the extraction of total RNA from mammalian cell homogenate.
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Affiliation(s)
- David J Kinahan
- Biomedical Diagnostics Institute, Dublin City University, Glasnevin, Dublin 9, Ireland.
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32
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Al-Faqheri W, Ibrahim F, Thio THG, Arof H, Madou M. Novel liquid equilibrium valving on centrifugal microfluidic CD platform. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2013; 2013:5509-12. [PMID: 24110984 DOI: 10.1109/embc.2013.6610797] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
One of the main challenges faced by researchers in the field of microfluidic compact disc (CD) platforms is the control of liquid movement and sequencing during spinning. This paper presents a novel microfluidic valve based on the principle of liquid equilibrium on a rotating CD. The proposed liquid equilibrium valve operates by balancing the pressure produced by the liquids in a source and a venting chamber during spinning. The valve does not require external forces or triggers, and is able to regulate burst frequencies with high accuracy. In this work, we demonstrate that the burst frequency can be significantly raised by making just a small adjustment of the liquid height in the vent chamber. Finally, the proposed valve ng method can be used separately or combined with other valving methods in advance microfluidic processes.
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33
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Kazemzadeh A, Ganesan P, Ibrahim F, He S, Madou MJ. The effect of contact angles and capillary dimensions on the burst frequency of super hydrophilic and hydrophilic centrifugal microfluidic platforms, a CFD study. PLoS One 2013; 8:e73002. [PMID: 24069169 PMCID: PMC3772009 DOI: 10.1371/journal.pone.0073002] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2013] [Accepted: 07/15/2013] [Indexed: 11/18/2022] Open
Abstract
This paper employs the volume of fluid (VOF) method to numerically investigate the effect of the width, height, and contact angles on burst frequencies of super hydrophilic and hydrophilic capillary valves in centrifugal microfluidic systems. Existing experimental results in the literature have been used to validate the implementation of the numerical method. The performance of capillary valves in the rectangular and the circular microfluidic structures on super hydrophilic centrifugal microfluidic platforms is studied. The numerical results are also compared with the existing theoretical models and the differences are discussed. Our experimental and computed results show a minimum burst frequency occurring at square capillaries and this result is useful for designing and developing more sophisticated networks of capillary valves. It also predicts that in super hydrophilic microfluidics, the fluid leaks consistently from the capillary valve at low pressures which can disrupt the biomedical procedures in centrifugal microfluidic platforms.
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Affiliation(s)
- Amin Kazemzadeh
- Department of Mechanical Engineering, University of Malaya, Kuala Lumpur, Malaysia
- Medical Informatics & Biological Micro-electro-mechanical Systems (MIMEMS) Specialized Laboratory, Department of Biomedical Engineering, University of Malaya, Kuala Lumpur, Malaysia
| | - Poo Ganesan
- Department of Mechanical Engineering, University of Malaya, Kuala Lumpur, Malaysia
- Medical Informatics & Biological Micro-electro-mechanical Systems (MIMEMS) Specialized Laboratory, Department of Biomedical Engineering, University of Malaya, Kuala Lumpur, Malaysia
- * E-mail:
| | - Fatimah Ibrahim
- Medical Informatics & Biological Micro-electro-mechanical Systems (MIMEMS) Specialized Laboratory, Department of Biomedical Engineering, University of Malaya, Kuala Lumpur, Malaysia
| | - Shuisheng He
- Department of Mechanical Engineering, University of Sheffield, Sheffield, United Kingdom
| | - Marc J. Madou
- Department of Biomedical Engineering, University of California Irvine, Irvine, California, United States of America
- Department of Mechanical and Aerospace Engineering, University of California Irvine, Irvine, California, United States of America
- Ulsan National Institute of Science and Technology (UNIST), World Class University (WCU), Ulsan, South Korea
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34
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Thio THG, Ibrahim F, Al-Faqheri W, Moebius J, Khalid NS, Soin N, Kahar MKBA, Madou M. Push pull microfluidics on a multi-level 3D CD. LAB ON A CHIP 2013; 13:3199-209. [PMID: 23774994 PMCID: PMC3816008 DOI: 10.1039/c3lc00004d] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
A technique known as thermo-pneumatic (TP) pumping is used to pump fluids on a microfluidic compact disc (CD) back towards the CD center against the centrifugal force that pushes liquids from the center to the perimeter of the disc. Trapped air expands in a TP air chamber during heating, and this creates positive pressure on liquids located in chambers connected to that chamber. While the TP air chamber and connecting channels are easy to fabricate in a one-level CD manufacturing technique, this approach provides only one way pumping between two chambers, is real-estate hungry and leads to unnecessary heating of liquids in close proximity to the TP chamber. In this paper, we present a novel TP push and pull pumping method which allows for pumping of liquid in any direction between two connected liquid chambers. To ensure that implementation of TP push and pull pumping also addresses the issue of space and heating challenges, a multi-level 3D CD design is developed, and localized forced convection heating, rather than infra-red (IR) is applied. On a multi-level 3D CD, the TP features are placed on a top level separate from the rest of the microfluidic processes that are implemented on a lower separate level. This approach allows for heat shielding of the microfluidic process level, and efficient usage of space on the CD for centrifugal handling of liquids. The use of localized forced convection heating, rather than infra-red (IR) or laser heating in earlier implementations allows not only for TP pumping of liquids while the CD is spinning but also makes heat insulation for TP pumping and other fluidic functions easier. To aid in future implementations of TP push and pull pumping on a multi-level 3D CD, study on CD surface heating is also presented. In this contribution, we also demonstrate an advanced application of pull pumping through the implementation of valve-less switch pumping.
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Affiliation(s)
- Tzer Hwai Gilbert Thio
- Medical Informatics & Biological Micro-electro-mechanical Systems (MIMEMS) Specialized Laboratory, Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - Fatimah Ibrahim
- Medical Informatics & Biological Micro-electro-mechanical Systems (MIMEMS) Specialized Laboratory, Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia
- Fax: 603 7967 4579; Tel: XX XXXX X603-7967-6818XXX;
| | - Wisam Al-Faqheri
- Medical Informatics & Biological Micro-electro-mechanical Systems (MIMEMS) Specialized Laboratory, Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - Jacob Moebius
- Medical Informatics & Biological Micro-electro-mechanical Systems (MIMEMS) Specialized Laboratory, Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia
- Department of Biomedical Engineering, University of California, Irvine, Irvine, 92697, United States
| | - Noor Sakinah Khalid
- Medical Informatics & Biological Micro-electro-mechanical Systems (MIMEMS) Specialized Laboratory, Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - Norhayati Soin
- Medical Informatics & Biological Micro-electro-mechanical Systems (MIMEMS) Specialized Laboratory, Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia
- Department of Electrical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - Maria Kahar Bador Abdul Kahar
- Medical Informatics & Biological Micro-electro-mechanical Systems (MIMEMS) Specialized Laboratory, Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia
| | - Marc Madou
- Medical Informatics & Biological Micro-electro-mechanical Systems (MIMEMS) Specialized Laboratory, Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia
- Department of Biomedical Engineering, University of California, Irvine, Irvine, 92697, United States
- Department of Mechanical and Aerospace Engineering, University of California, Irvine, Irvine, 92697, United States
- Ulsan National Institute of Science and Technology (UNIST), World Class University (WCU), Ulsan, South Korea
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35
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Al-Faqheri W, Ibrahim F, Thio THG, Moebius J, Joseph K, Arof H, Madou M. Vacuum/compression valving (VCV) using parrafin-wax on a centrifugal microfluidic CD platform. PLoS One 2013; 8:e58523. [PMID: 23505528 PMCID: PMC3594320 DOI: 10.1371/journal.pone.0058523] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2012] [Accepted: 02/05/2013] [Indexed: 11/18/2022] Open
Abstract
This paper introduces novel vacuum/compression valves (VCVs) utilizing paraffin wax. A VCV is implemented by sealing the venting channel/hole with wax plugs (for normally-closed valve), or to be sealed by wax (for normally-open valve), and is activated by localized heating on the CD surface. We demonstrate that the VCV provides the advantages of avoiding unnecessary heating of the sample/reagents in the diagnostic process, allowing for vacuum sealing of the CD, and clear separation of the paraffin wax from the sample/reagents in the microfluidic process. As a proof of concept, the microfluidic processes of liquid flow switching and liquid metering is demonstrated with the VCV. Results show that the VCV lowers the required spinning frequency to perform the microfluidic processes with high accuracy and ease of control.
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Affiliation(s)
- Wisam Al-Faqheri
- Medical Informatics and Biological Micro-electro-mechanical Systems Specialized Laboratory, Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, Kuala Lumpur, Malaysia
| | - Fatimah Ibrahim
- Medical Informatics and Biological Micro-electro-mechanical Systems Specialized Laboratory, Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, Kuala Lumpur, Malaysia
- * E-mail:
| | - Tzer Hwai Gilbert Thio
- Medical Informatics and Biological Micro-electro-mechanical Systems Specialized Laboratory, Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, Kuala Lumpur, Malaysia
| | - Jacob Moebius
- Medical Informatics and Biological Micro-electro-mechanical Systems Specialized Laboratory, Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, Kuala Lumpur, Malaysia
- Department of Biomedical Engineering, University of California Irvine, Irvine, United States of America
| | - Karunan Joseph
- Medical Informatics and Biological Micro-electro-mechanical Systems Specialized Laboratory, Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, Kuala Lumpur, Malaysia
| | - Hamzah Arof
- Department of Electrical Engineering, Faculty of Engineering, University of Malaya, Kuala Lumpur, Malaysia
| | - Marc Madou
- Medical Informatics and Biological Micro-electro-mechanical Systems Specialized Laboratory, Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, Kuala Lumpur, Malaysia
- Department of Biomedical Engineering, University of California Irvine, Irvine, United States of America
- Department of Mechanical and Aerospace Engineering, University of California Irvine, Irvine, United States of America
- Ulsan National Institute of Science and Technology, World Class University, Ulsan, South Korea
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36
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Thio THG, Ibrahim F, Al-Faqheri W, Soin N, Abdul Kahar MKB, Madou M. Multi-level 3D implementation of thermo-pneumatic pumping on centrifugal microfluidic CD platforms. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2013; 2013:5513-5516. [PMID: 24110985 DOI: 10.1109/embc.2013.6610798] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Thermo-pneumatic (TP) pumping is a method employing the principle of expanding heated air to transfer fluids back towards the CD center on the centrifugal microfluidic CD platform. While the TP features are easy to fabricate as no moving parts are involved, it consumes extra real estate on the CD, and because heating is involved, it introduces unnecessary heating to the fluids on the CD. To overcome these limitations, we introduce a multi-level 3D approach and implement forced convection heating. In a multi-level 3D CD, the TP features are relocated to a separate top level, while the microfluidic process remains on a lower bottom level. This allows for heat shielding of the fluids in the microfluidic process level, and also improve usage of space on the CD. To aid in future implementations of TP pumping on a multi-level 3D CD, studies on the effect of heat source setting, and the effect of positioning the TP feature (it distance from the CD center) on CD surface heating are also presented. In this work, we successfully demonstrate a multi-level 3D approach to implement TP pumping on the microfluidic CD platform.
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