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Yan Y, Huang X, Yuan L, Tang Y, Zhu W, Du H, Nie J, Zhang L, Liao S, Tang X, Zhang Y. Single-step batch fabrication of microfluidic paper-based analytical devices with a 3D printer and their applications in nanoenzyme-enhanced visual detection of dopamine. Anal Bioanal Chem 2024:10.1007/s00216-024-05337-2. [PMID: 38780654 DOI: 10.1007/s00216-024-05337-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2024] [Revised: 04/26/2024] [Accepted: 05/06/2024] [Indexed: 05/25/2024]
Abstract
Wax printing is the most widely used method for fabricating microfluidic paper-based analytical devices (μPADs), but it still suffers from disadvantages like discontinuation of wax printers and need for additional equipment for heating treatment. To address these issues, this work initially describes a new class of wax printing approach for high-precision, batch fabrication of μPADs using a household 3D printer. It only involves a one patterning step of printing polyethylene wax into rice paper body. Under optimized parameters, a fabrication resolution, namely the minimum hydrophilic channel width, down to ~189 ± 30 μm could be achieved. In addition, the analytical applicability of such polyethylene wax-patterned μPADs was demonstrated well with enhanced colorimetric detection of dopamine as a model analyte by combining metal-organic framework (MOF) based nanoenzymes (ZIF-67) with a smartphone (for portable quantitative readout). The developed nanosensor could linearly detect dopamine over a concentration range from 10 to 1000 μM, with a detection limit of ca. 2.75 μM (3σ). The recovery results for analyzing several real samples (i.e., pig feed, chicken feed, pork and human serum) were between 91.82 and 102.79%, further validating its good detection accuracy for potential practical applications in food safety and medical diagnosis.
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Affiliation(s)
- Yongkang Yan
- Guangxi Key Laboratory of Electrochemical and Magnetochemical Function Materials, College of Chemistry and Bioengineering, Guilin University of Technology, 12 Jiangan Road, Guilin, 541004, People's Republic of China
| | - Xueer Huang
- Guangxi Key Laboratory of Electrochemical and Magnetochemical Function Materials, College of Chemistry and Bioengineering, Guilin University of Technology, 12 Jiangan Road, Guilin, 541004, People's Republic of China
| | - Lili Yuan
- Guangxi Key Laboratory of Electrochemical and Magnetochemical Function Materials, College of Chemistry and Bioengineering, Guilin University of Technology, 12 Jiangan Road, Guilin, 541004, People's Republic of China
| | - Yiyue Tang
- Guangxi Key Laboratory of Electrochemical and Magnetochemical Function Materials, College of Chemistry and Bioengineering, Guilin University of Technology, 12 Jiangan Road, Guilin, 541004, People's Republic of China
| | - Wenli Zhu
- Guangxi Key Laboratory of Electrochemical and Magnetochemical Function Materials, College of Chemistry and Bioengineering, Guilin University of Technology, 12 Jiangan Road, Guilin, 541004, People's Republic of China
| | - Hancong Du
- Guangxi Key Laboratory of Electrochemical and Magnetochemical Function Materials, College of Chemistry and Bioengineering, Guilin University of Technology, 12 Jiangan Road, Guilin, 541004, People's Republic of China
| | - Jinfang Nie
- Guangxi Key Laboratory of Electrochemical and Magnetochemical Function Materials, College of Chemistry and Bioengineering, Guilin University of Technology, 12 Jiangan Road, Guilin, 541004, People's Republic of China.
| | - Lang Zhang
- Institute of Rheumatology and Immunology, Affiliated Hospital of North Sichuan Medical College, 234 Fujiang Road, Nanchong, 637000, People's Republic of China
| | - Shan Liao
- Guilin Zhonghui Technology Development Co., Ltd., 13 Lushan Road, Guilin, 541100, People's Republic of China
| | - Xuehui Tang
- URIT Medical Electronic Co., Ltd., No.D-07 Information Industry District, High-Tech Zone, Guilin, 541100, People's Republic of China
| | - Yun Zhang
- Guangxi Key Laboratory of Electrochemical and Magnetochemical Function Materials, College of Chemistry and Bioengineering, Guilin University of Technology, 12 Jiangan Road, Guilin, 541004, People's Republic of China.
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Atabakhsh S, Haji Abbasali H, Jafarabadi Ashtiani S. Thermally programmable time delay switches for multi-step assays in paper-based microfluidics. Talanta 2024; 271:125695. [PMID: 38295445 DOI: 10.1016/j.talanta.2024.125695] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Revised: 12/18/2023] [Accepted: 01/17/2024] [Indexed: 02/02/2024]
Abstract
Paper-based microfluidic devices offer advantages such as low cost and disposability for point-of-care diagnostic applications. However, actuation of fluids on paper can be a challenge in multi-step and complex assays. In this work, a thermally programmable time-delay switch (TPTDS) is presented which operates by causing delays in the fluid path of a microfluidics paper-based analytical device (μPAD) by utilizing screen-printed wax micro-bridges. The time-delay is achieved through an electrical power feedback loop which indirectly adjusts the temperature of each individual micro-bridge, melting the wax into the paper. The melted wax manipulates the fluid flow depending on its penetration depth into the paper channel, which is a function of the applied temperature. To demonstrate functionality of the proposed method, the TPTDS is employed to automate and perform the nitrate assay which requires sequential delivery of reagents. Colorimetric detection is used to quantify the results by utilizing an electronic color sensor.
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Affiliation(s)
- Saeed Atabakhsh
- Department of Electrical Engineering, Roudehen Branch, Islamic Azad University, Roudehen, Iran
| | - Hossein Haji Abbasali
- School of Electrical and Computer Engineering, College of Engineering, University of Tehran, Tehran, 14395/515, Iran
| | - Shahin Jafarabadi Ashtiani
- School of Electrical and Computer Engineering, College of Engineering, University of Tehran, Tehran, 14395/515, Iran.
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Yu Z, Chen Y, Li J, Chen C, Lu H, Chen S, Zhang T, Guo T, Zhu Y, Jin J, Yan S, Chen H. A tempo-spatial controllable microfluidic shear-stress generator for in-vitro mimicking of the thrombus. J Nanobiotechnology 2024; 22:187. [PMID: 38632623 PMCID: PMC11022418 DOI: 10.1186/s12951-024-02334-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Accepted: 02/09/2024] [Indexed: 04/19/2024] Open
Abstract
Pathological conditions linked to shear stress have been identified in hematological diseases, cardiovascular diseases, and cancer. These conditions often exhibit significantly elevated shear stress levels, surpassing 1000 dyn/cm2 in severely stenotic arteries. Heightened shear stress can induce mechanical harm to endothelial cells, potentially leading to bleeding and fatal consequences. However, current technology still grapples with limitations, including inadequate flexibility in simulating bodily shear stress environments, limited range of shear stress generation, and spatial and temporal adaptability. Consequently, a comprehensive understanding of the mechanisms underlying the impact of shear stress on physiological and pathological conditions, like thrombosis, remains inadequate. To address these limitations, this study presents a microfluidic-based shear stress generation chip as a proposed solution. The chip achieves a substantial 929-fold variation in shear stress solely by adjusting the degree of constriction in branch channels after PDMS fabrication. Experiments demonstrated that a rapid increase in shear stress up to 1000 dyn/cm2 significantly detached 88.2% cells from the substrate. Long-term exposure (24 h) to shear stress levels below 8.3 dyn/cm2 did not significantly impact cell growth. Furthermore, cells exposed to shear stress levels equal to or greater than 8.3 dyn/cm2 exhibited significant alterations in aspect ratio and orientation, following a normal distribution. This microfluidic chip provides a reliable tool for investigating cellular responses to the wide-ranging shear stress existing in both physiological and pathological flow conditions.
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Affiliation(s)
- Zhihang Yu
- School of Mechanical Engineering and Automation, Harbin Institute of Technology, Shenzhen, Shenzhen, 518055, China
| | - Yiqun Chen
- School of Mechanical Engineering and Automation, Harbin Institute of Technology, Shenzhen, Shenzhen, 518055, China
| | - Jingjing Li
- Graduate School of Biomedical Engineering, The University of New South Wales, Sydney, NSW, 2052, Australia
| | - Chang Chen
- School of Mechanical Engineering and Automation, Harbin Institute of Technology, Shenzhen, Shenzhen, 518055, China
| | - Huaxiu Lu
- School of Mechanical Engineering and Automation, Harbin Institute of Technology, Shenzhen, Shenzhen, 518055, China
| | - Siyuan Chen
- School of Mechanical Engineering and Automation, Harbin Institute of Technology, Shenzhen, Shenzhen, 518055, China
| | - Tingting Zhang
- School of Mechanical Engineering and Automation, Harbin Institute of Technology, Shenzhen, Shenzhen, 518055, China
| | - Tianruo Guo
- Graduate School of Biomedical Engineering, The University of New South Wales, Sydney, NSW, 2052, Australia
| | - Yonggang Zhu
- School of Mechanical Engineering and Automation, Harbin Institute of Technology, Shenzhen, Shenzhen, 518055, China
| | - Jing Jin
- School of Mechanical Engineering and Automation, Harbin Institute of Technology, Shenzhen, Shenzhen, 518055, China.
| | - Sheng Yan
- Institute for Advanced Study, Shenzhen University, Shenzhen, 518060, China.
| | - Huaying Chen
- School of Mechanical Engineering and Automation, Harbin Institute of Technology, Shenzhen, Shenzhen, 518055, China.
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Li B, Zhang L, Bai S, Jin J, Chen H. A brief overview of passive microvalves in microfluidics: Mechanism, manufacturing, and applications. BIOMICROFLUIDICS 2024; 18:021506. [PMID: 38659429 PMCID: PMC11037934 DOI: 10.1063/5.0188807] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2023] [Accepted: 04/05/2024] [Indexed: 04/26/2024]
Abstract
Microvalves play a crucial role in manipulating fluid states within a microfluidic system and are finding widespread applications in fields such as biology, medicine, and environmental preservation. Leveraging the characteristics and features of microvalves enables the realization of various complicated microfluidic functions. Continuous advancement in the manufacturing process contributes to more flexible control modes for passive microvalves. As a consequence, these valves are progressively shrinking in size while simultaneously improving in precision and stability. Although active microvalves have the benefits of low leakage, rapid response time, and wide adaptability range, the energy supply system limits the size and even their applicability in integration and miniaturization. In comparison, passive microvalves have the advantage of relying solely on the fluid flow or fluid driving pressure to control the open/close of fluid flow over active microvalves, in spite of having slightly reduced control accuracy. Their self-sustaining feature is highly consistent with the need for assembly and miniaturization in the point-of-care testing technology. Hence, these valves have attracted significant interest for research and application purposes. This review focuses on the recent literature on passive microvalves and details existing passive microvalves from three different aspects: operating principle, processing method, and applications. This work aims to increase the visibility of passive microvalves among researchers and enhance their comprehension by classifying them according to the aforementioned three aspects, facilitating the practical applications and further developments of passive microvalves. Additionally, this paper is expected to serve as a comprehensive and systematic reference for interdisciplinary researchers that intend to design related microfluidic systems.
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Affiliation(s)
- Bin Li
- School of Mechanical Engineering and Automation, Harbin Institute of Technology, Shenzhen, Shenzhen 518055, China
| | - Ludan Zhang
- School of Mechanical Engineering and Automation, Harbin Institute of Technology, Shenzhen, Shenzhen 518055, China
| | - Siwei Bai
- Authors to whom correspondence should be addressed:; ; and . Tel.: +86 755 8615 3249
| | - Jing Jin
- School of Mechanical Engineering and Automation, Harbin Institute of Technology, Shenzhen, Shenzhen 518055, China
| | - Huaying Chen
- School of Mechanical Engineering and Automation, Harbin Institute of Technology, Shenzhen, Shenzhen 518055, China
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Tong W, Shi J, Yu Z, Ran B, Chen H, Zhu Y. High sensitivity and automatic chemiluminescence detection of glucose and lactate using a spin-disc paper-based device. LAB ON A CHIP 2024; 24:810-818. [PMID: 38224458 DOI: 10.1039/d3lc00937h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/16/2024]
Abstract
This paper reports a spin-disc paper-based device with 10 individual detection units containing electromagnetic modules controlling the sample incubation time before chemiluminescence (CL) signal detection. After the sample was added to the top paper chip and incubated with the enzyme, the electromagnet was turned off to allow contact between the top and bottom paper. The H2O2 generated by the sample flowed vertically to the bottom paper and initiated the oxidase of the luminol to generate the CL signal. After one detection the disc was automatically rotated to the next position to repeat the above detection. The advantage of using the device over the lateral flow and the in situ detection was firstly proved using the detection of H2O2 and the glucose/lactate sample with 5 minute incubation. The CL intensity was increased 300 times/1000 times as the glucose/lactate was incubated for 5 minutes compared to the non-incubated samples. Afterward, the device was employed to separately detect glucose and lactate diluted in PBS, artificial sweat, artificial saliva, and fresh cell culture media. Finally, the device was employed to detect the glucose and lactate in the media collected over the 24 hour culture of PC3 cells. The uptake and production rates of glucose and lactate were correspondingly determined as 0.328 ± 0.015 pmol h-1 per cell and 1.254 ± 0.053 pmol h-1 per cell, respectively. The reported device has wide application potential due to its capabilities in automatic detection of multiple samples with very high sensitivity and small sample volume (down to 0.5 μL).
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Affiliation(s)
- Wenqiang Tong
- School of Science, Harbin Institute of Technology, Shenzhen, Shenzhen 518055, China
- Center for Microflows and Nanoflows, School of Mechanical Engineering and Automation, Harbin Institute of Technology, Shenzhen, Shenzhen 518055, China
| | - Jiaming Shi
- School of Science, Harbin Institute of Technology, Shenzhen, Shenzhen 518055, China
- Center for Microflows and Nanoflows, School of Mechanical Engineering and Automation, Harbin Institute of Technology, Shenzhen, Shenzhen 518055, China
| | - Zhihang Yu
- School of Science, Harbin Institute of Technology, Shenzhen, Shenzhen 518055, China
- Center for Microflows and Nanoflows, School of Mechanical Engineering and Automation, Harbin Institute of Technology, Shenzhen, Shenzhen 518055, China
| | - Bin Ran
- School of Science, Harbin Institute of Technology, Shenzhen, Shenzhen 518055, China
- Center for Microflows and Nanoflows, School of Mechanical Engineering and Automation, Harbin Institute of Technology, Shenzhen, Shenzhen 518055, China
| | - Huaying Chen
- School of Mechanical Engineering and Automation, Harbin Institute of Technology, Shenzhen, Shenzhen 518055, China.
- Center for Microflows and Nanoflows, School of Mechanical Engineering and Automation, Harbin Institute of Technology, Shenzhen, Shenzhen 518055, China
| | - Yonggang Zhu
- School of Mechanical Engineering and Automation, Harbin Institute of Technology, Shenzhen, Shenzhen 518055, China.
- Center for Microflows and Nanoflows, School of Mechanical Engineering and Automation, Harbin Institute of Technology, Shenzhen, Shenzhen 518055, China
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Li S, Zhang J, He J, Liu W, Wang Y, Huang Z, Pang H, Chen Y. Functional PDMS Elastomers: Bulk Composites, Surface Engineering, and Precision Fabrication. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023; 10:e2304506. [PMID: 37814364 DOI: 10.1002/advs.202304506] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Indexed: 10/11/2023]
Abstract
Polydimethylsiloxane (PDMS)-the simplest and most common silicone compound-exemplifies the central characteristics of its class and has attracted tremendous research attention. The development of PDMS-based materials is a vivid reflection of the modern industry. In recent years, PDMS has stood out as the material of choice for various emerging technologies. The rapid improvement in bulk modification strategies and multifunctional surfaces has enabled a whole new generation of PDMS-based materials and devices, facilitating, and even transforming enormous applications, including flexible electronics, superwetting surfaces, soft actuators, wearable and implantable sensors, biomedicals, and autonomous robotics. This paper reviews the latest advances in the field of PDMS-based functional materials, with a focus on the added functionality and their use as programmable materials for smart devices. Recent breakthroughs regarding instant crosslinking and additive manufacturing are featured, and exciting opportunities for future research are highlighted. This review provides a quick entrance to this rapidly evolving field and will help guide the rational design of next-generation soft materials and devices.
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Affiliation(s)
- Shaopeng Li
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, Shanghai, 201620, China
| | - Jiaqi Zhang
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, Shanghai, 201620, China
| | - Jian He
- Yizhi Technology (Shanghai) Co., Ltd, No. 99 Danba Road, Putuo District, Shanghai, 200062, China
| | - Weiping Liu
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, Shanghai, 201620, China
- Center for Composites, COMAC Shanghai Aircraft Manufacturing Co. Ltd, Shanghai, 201620, China
| | - YuHuang Wang
- Department of Chemistry and Biochemistry, University of Maryland, College Park, MD, 20742, USA
- Maryland NanoCenter, University of Maryland, College Park, MD, 20742, USA
| | - Zhongjie Huang
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, Shanghai, 201620, China
| | - Huan Pang
- School of Chemistry and Chemical Engineering, Yangzhou University, Yangzhou, Jiangsu, 225009, China
| | - Yiwang Chen
- National Engineering Research Center for Carbohydrate Synthesis/Key Lab of Fluorine and Silicon for Energy Materials and Chemistry of Ministry of Education, Jiangxi Normal University, 99 Ziyang Avenue, Nanchang, 330022, China
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Tony A, Badea I, Yang C, Liu Y, Wells G, Wang K, Yin R, Zhang H, Zhang W. The Additive Manufacturing Approach to Polydimethylsiloxane (PDMS) Microfluidic Devices: Review and Future Directions. Polymers (Basel) 2023; 15:1926. [PMID: 37112073 PMCID: PMC10147032 DOI: 10.3390/polym15081926] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2023] [Revised: 04/10/2023] [Accepted: 04/12/2023] [Indexed: 04/29/2023] Open
Abstract
This paper presents a comprehensive review of the literature for fabricating PDMS microfluidic devices by employing additive manufacturing (AM) processes. AM processes for PDMS microfluidic devices are first classified into (i) the direct printing approach and (ii) the indirect printing approach. The scope of the review covers both approaches, though the focus is on the printed mold approach, which is a kind of the so-called replica mold approach or soft lithography approach. This approach is, in essence, casting PDMS materials with the mold which is printed. The paper also includes our on-going effort on the printed mold approach. The main contribution of this paper is the identification of knowledge gaps and elaboration of future work toward closing the knowledge gaps in fabrication of PDMS microfluidic devices. The second contribution is the development of a novel classification of AM processes from design thinking. There is also a contribution in clarifying confusion in the literature regarding the soft lithography technique; this classification has provided a consistent ontology in the sub-field of the fabrication of microfluidic devices involving AM processes.
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Affiliation(s)
- Anthony Tony
- Department of Mechanical Engineering, University of Saskatchewan, Saskatoon, SK S7N 5A9, Canada; (A.T.); (C.Y.); (Y.L.)
| | - Ildiko Badea
- College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, SK S7N 5E5, Canada;
| | - Chun Yang
- Department of Mechanical Engineering, University of Saskatchewan, Saskatoon, SK S7N 5A9, Canada; (A.T.); (C.Y.); (Y.L.)
| | - Yuyi Liu
- Department of Mechanical Engineering, University of Saskatchewan, Saskatoon, SK S7N 5A9, Canada; (A.T.); (C.Y.); (Y.L.)
| | - Garth Wells
- Synchrotron Laboratory for Micro and Nano Devices (SyLMAND), Canadian Light Source, Saskatoon, SK S7N 2V3, Canada;
| | - Kemin Wang
- School of Mechatronics and Automation, Shanghai University, Shanghai 200444, China;
| | - Ruixue Yin
- School of Mechanical and Power Engineering, East China University of Science and Technology, Shanghai 200237, China;
| | - Hongbo Zhang
- School of Mechanical and Power Engineering, East China University of Science and Technology, Shanghai 200237, China;
| | - Wenjun Zhang
- Department of Mechanical Engineering, University of Saskatchewan, Saskatoon, SK S7N 5A9, Canada; (A.T.); (C.Y.); (Y.L.)
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Chen L, Guo X, Sun X, Zhang S, Wu J, Yu H, Zhang T, Cheng W, Shi Y, Pan L. Porous Structural Microfluidic Device for Biomedical Diagnosis: A Review. MICROMACHINES 2023; 14:547. [PMID: 36984956 PMCID: PMC10051279 DOI: 10.3390/mi14030547] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Revised: 02/21/2023] [Accepted: 02/22/2023] [Indexed: 06/18/2023]
Abstract
Microfluidics has recently received more and more attention in applications such as biomedical, chemical and medicine. With the development of microelectronics technology as well as material science in recent years, microfluidic devices have made great progress. Porous structures as a discontinuous medium in which the special flow phenomena of fluids lead to their potential and special applications in microfluidics offer a unique way to develop completely new microfluidic chips. In this article, we firstly introduce the fabrication methods for porous structures of different materials. Then, the physical effects of microfluid flow in porous media and their related physical models are discussed. Finally, the state-of-the-art porous microfluidic chips and their applications in biomedicine are summarized, and we present the current problems and future directions in this field.
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Affiliation(s)
| | | | - Xidi Sun
- Correspondence: (X.S.); (Y.S.); (L.P.)
| | | | | | | | | | | | - Yi Shi
- Correspondence: (X.S.); (Y.S.); (L.P.)
| | - Lijia Pan
- Correspondence: (X.S.); (Y.S.); (L.P.)
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Chen C, Li P, Guo T, Chen S, Xu D, Chen H. Generation of Dynamic Concentration Profile Using A Microfluidic Device Integrating Pneumatic Microvalves. BIOSENSORS 2022; 12:bios12100868. [PMID: 36291005 PMCID: PMC9599525 DOI: 10.3390/bios12100868] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 10/08/2022] [Accepted: 10/09/2022] [Indexed: 06/12/2023]
Abstract
Generating and maintaining the concentration dilutions of diffusible molecules in microchannels is critical for high-throughput chemical and biological analysis. Conventional serial network microfluidic technologies can generate high orders of arbitrary concentrations by a predefined microchannel network. However, a previous design requires a large occupancy area and is unable to dynamically generate different profiles in the same chip, limiting its applications. This study developed a microfluidic device enabling dynamic variations of both the concentration in the same channel and the concentration distribution in multiple channels by adjusting the flow resistance using programmable pneumatic microvalves. The key component (the pneumatic microvalve) allowed dynamic adjustment of the concentration profile but occupied a tiny space. Additionally, a Matlab program was developed to calculate the flow rates and flow resistance of various sections of the device, which provided theoretical guidance for dimension design. In silico investigations were conducted to evaluate the microvalve deformation with widths from 100 to 300 µm and membrane thicknesses of 20 and 30 µm under the activation pressures between 0 and 2000 mbar. The flow resistance of the deformed valve was studied both numerically and experimentally and an empirical model for valve flow resistance with the form of Rh=aebP was proposed. Afterward, the fluid flow in the valve region was characterized using Micro PIV to further demonstrate the adjustment mechanism of the flow resistance. Then, the herringbone structures were employed for fast mixing to allow both quick variation of concentration and minor space usage of the channel network. Finally, an empirical formula-supported computational program was developed to provide the activation pressures required for the specific concentration profile. Both linear (Ck = -0.2k + 1) and nonlinear (Ck = (110)k) concentration distribution in four channels were varied using the same device by adjusting microvalves. The device demonstrated the capability to control the concentration profile dynamically in a small space, offering superior application potentials in analytical chemistry, drug screening, and cell biology research.
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Affiliation(s)
- Chang Chen
- School of Mechanical Engineering and Automation, Harbin Institute of Technology, Shenzhen 518055, China
| | - Panpan Li
- School of Science, Harbin Institute of Technology, Shenzhen 518055, China
| | - Tianruo Guo
- Graduate School of Biomedical Engineering, The University of New South Wales, Sydney, NSW 2052, Australia
| | - Siyuan Chen
- School of Science, Harbin Institute of Technology, Shenzhen 518055, China
| | - Dong Xu
- School of Science, Harbin Institute of Technology, Shenzhen 518055, China
| | - Huaying Chen
- School of Mechanical Engineering and Automation, Harbin Institute of Technology, Shenzhen 518055, China
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