1
|
Rutkowska KA, Sobotka P, Grom M, Baczyński S, Juchniewicz M, Marchlewicz K, Dybko A. A Novel Approach for the Creation of Electrically Controlled LC:PDMS Microstructures. SENSORS 2022; 22:s22114037. [PMID: 35684658 PMCID: PMC9185514 DOI: 10.3390/s22114037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Revised: 05/23/2022] [Accepted: 05/24/2022] [Indexed: 02/04/2023]
Abstract
This work presents research on unique optofluidic systems in the form of air channels fabricated in PDMS and infiltrated with liquid crystalline material. The proposed LC:PDMS structures represent an innovative solution due to the use of microchannel electrodes filled with a liquid metal alloy. The latter allows for the easy and dynamic reconfiguration of the system and eliminates technological issues experienced by other research groups. The paper discusses the design, fabrication, and testing methods for tunable LC:PDMS structures. Particular emphasis was placed on determining their properties after applying an external electric field, depending on the geometrical parameters of the system. The conclusions of the performed investigations may contribute to the definition of guidelines for both LC:PDMS devices and a new class of potential sensing elements utilizing polymers and liquid crystals in their structures.
Collapse
Affiliation(s)
- Katarzyna A. Rutkowska
- Faculty of Physics, Warsaw University of Technology, Koszykowa 75, 00-662 Warsaw, Poland; (P.S.); (M.G.); (S.B.)
- Correspondence:
| | - Piotr Sobotka
- Faculty of Physics, Warsaw University of Technology, Koszykowa 75, 00-662 Warsaw, Poland; (P.S.); (M.G.); (S.B.)
| | - Monika Grom
- Faculty of Physics, Warsaw University of Technology, Koszykowa 75, 00-662 Warsaw, Poland; (P.S.); (M.G.); (S.B.)
| | - Szymon Baczyński
- Faculty of Physics, Warsaw University of Technology, Koszykowa 75, 00-662 Warsaw, Poland; (P.S.); (M.G.); (S.B.)
| | - Marcin Juchniewicz
- Centre for Advanced Materials and Technologies (CEZAMAT), Warsaw University of Technology, Poleczki 19, 02-822 Warsaw, Poland;
| | - Kasper Marchlewicz
- Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw, Poland; (K.M.); (A.D.)
| | - Artur Dybko
- Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw, Poland; (K.M.); (A.D.)
| |
Collapse
|
2
|
Ling SD, Geng Y, Chen A, Du Y, Xu J. Enhanced single-cell encapsulation in microfluidic devices: From droplet generation to single-cell analysis. BIOMICROFLUIDICS 2020; 14:061508. [PMID: 33381250 PMCID: PMC7758092 DOI: 10.1063/5.0018785] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Accepted: 12/09/2020] [Indexed: 05/24/2023]
Abstract
Single-cell analysis to investigate cellular heterogeneity and cell-to-cell interactions is a crucial compartment to answer key questions in important biological mechanisms. Droplet-based microfluidics appears to be the ideal platform for such a purpose because the compartmentalization of single cells into microdroplets offers unique advantages of enhancing assay sensitivity, protecting cells against external stresses, allowing versatile and precise manipulations over tested samples, and providing a stable microenvironment for long-term cell proliferation and observation. The present Review aims to give a preliminary guidance for researchers from different backgrounds to explore the field of single-cell encapsulation and analysis. A comprehensive and introductory overview of the droplet formation mechanism, fabrication methods of microchips, and a myriad of passive and active encapsulation techniques to enhance single-cell encapsulation efficiency were presented. Meanwhile, common methods for single-cell analysis, especially for long-term cell proliferation, differentiation, and observation inside microcapsules, are briefly introduced. Finally, the major challenges faced in the field are illustrated, and potential prospects for future work are discussed.
Collapse
Affiliation(s)
- Si Da Ling
- The State Key Laboratory of Chemical Engineering, Department of Chemical Engineering, Tsinghua University, Beijing 100084, China
| | - Yuhao Geng
- The State Key Laboratory of Chemical Engineering, Department of Chemical Engineering, Tsinghua University, Beijing 100084, China
| | - An Chen
- The State Key Laboratory of Chemical Engineering, Department of Chemical Engineering, Tsinghua University, Beijing 100084, China
| | - Yanan Du
- Department of Biomedical Engineering, School of Medicine, Tsinghua-Peking Center for Life Sciences, Tsinghua University, Beijing 100084, China
| | - Jianhong Xu
- The State Key Laboratory of Chemical Engineering, Department of Chemical Engineering, Tsinghua University, Beijing 100084, China
| |
Collapse
|
3
|
Chou PC, Lin FP, Hsu HL, Chang CJ, Lu CH, Chen JK. Electrorheological Sensor Encapsulating Microsphere Media for Plague Diagnosis with Rapid Visualization. ACS Sens 2020; 5:665-673. [PMID: 31869212 DOI: 10.1021/acssensors.9b01529] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Plague is a disease infected by an etiological agent, which is transmitted from fleas to a variety of wildlife rodents. Therefore, rapid diagnosis of plague on-site in the field is important. Polystyrene microspheres (SMs) of 2.2 μm diameter were synthesized by emulsion polymerization to adsorb magnetic nanoparticles (FNs), resulting in core-/shell-structured microspheres that generate a significant contrast in relative permittivities between SMs and FNs. Electrorheological displays (EDs) consisting of two indium tin oxide glasses with spacers were constructed to contain core-/shell-structured SM/FN (SM@FN) solutions for observing their transmittance change. The ED encapsulating dispersed SM@FN solution exhibited an opaque state because light was scattered significantly without the application of an alternating electric field (AEF). In the presence of an AEF, the particle chaining behavior results in enhancement of the transmittance of ED. At a specific frequency, the so-called characteristic frequency (Fc), the transmittance reaches a maximum. Fc could be used as an indicator to mark the shell materials. The antibody of Yersinia pestis (ab-Yp) was coated onto the SM@FN as a biosensing medium. The Fc of ab-Yp-modified microspheres shifted from 200 to 750 kHz with antigen coupling of Y. pestis antigen (ag-Yp). In the absence of fluorescence labeling, the large change in ED transmittance could be visualized during the Y. pestis detection. The limit of detection and the limit of quantification were ∼30 and ∼40 ng/μL, respectively, obtained within 30 s according to the highest transmittance of ED under the AEF at 750 kHz. Y. pestis detection was not affected by Escherichia coli and Staphylococcus aureus significantly. Compared with other common immunoassays, including the secondary immunochemical or enzyme-linked steps, this simple electrorheological sensor with high sensitivity and selectivity could be a candidate for on-site plague diagnosis.
Collapse
Affiliation(s)
- Pai-Chien Chou
- Department of Thoracic Medicine, Taipei Medical University Hospital, Taipei 110, Taiwan, Republic of China
- Department of Materials and Science Engineering, National Taiwan University of Science and Technology, 43, Sec. 4, Keelung Road, Taipei 106, Taiwan, Republic of China
| | - Feng-Ping Lin
- Department of Materials and Science Engineering, National Taiwan University of Science and Technology, 43, Sec. 4, Keelung Road, Taipei 106, Taiwan, Republic of China
- Institute of Preventive Medicine, National Defense Medical Center, 161, Sec. 6, Minquan East Road, Neihu Dist., New Taipei City 114, Taiwan, ROC
| | - Hui-Ling Hsu
- Institute of Preventive Medicine, National Defense Medical Center, 161, Sec. 6, Minquan East Road, Neihu Dist., New Taipei City 114, Taiwan, ROC
| | - Chi-Jung Chang
- Department of Chemical Engineering, Feng Chia University, 100, Wenhwa Road, Seatwen, Taichung 40724, Taiwan, ROC
| | - Chien-Hsing Lu
- Department of Obstetrics and Gynecology, Taichung Veterans General Hospital, Taichung 40705, Taiwan
- Department of Obstetrics and Gynecology, National Yang-Ming University School of Medicine, Taipei 112, Taiwan
| | - Jem-Kun Chen
- Department of Materials and Science Engineering, National Taiwan University of Science and Technology, 43, Sec. 4, Keelung Road, Taipei 106, Taiwan, Republic of China
| |
Collapse
|
4
|
Chen K, Sui C, Wu Y, Ao Z, Guo SS, Guo F. A digital acoustofluidic device for on-demand and oil-free droplet generation. NANOTECHNOLOGY 2019; 30:084001. [PMID: 30523921 DOI: 10.1088/1361-6528/aaf3fd] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
We report a digital acoustofluidic device for on-demand and oil-free droplet generation. By applying a programmed radio frequency signal to a circular interdigital transducer, the dynamic focused acoustic pressure profiles generated rise up and dispense sample liquids from a reservoir to dynamically eject the droplets into the air. Our device allows droplets to be dispensed on demand with precisely controlled generation time and sequence, and accurate droplet volume. Moreover, we also demonstrate the generation of a droplet with a volume of 24 pL within 10 ms, as well as the encapsulation of a single cell into droplets. This acoustofluidic droplet generation technique is simple, biocompatible, and enables the on-demand droplet generation and encapsulation of many different biological materials with precise control, which is promising for single cell sampling and analysis applications.
Collapse
Affiliation(s)
- Keke Chen
- Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, School of Physics and Technology, Wuhan University, Wuhan 430072, People's Republic of China
| | | | | | | | | | | |
Collapse
|
5
|
Zhu P, Wang L. Passive and active droplet generation with microfluidics: a review. LAB ON A CHIP 2016; 17:34-75. [PMID: 27841886 DOI: 10.1039/c6lc01018k] [Citation(s) in RCA: 495] [Impact Index Per Article: 61.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Precise and effective control of droplet generation is critical for applications of droplet microfluidics ranging from materials synthesis to lab-on-a-chip systems. Methods for droplet generation can be either passive or active, where the former generates droplets without external actuation, and the latter makes use of additional energy input in promoting interfacial instabilities for droplet generation. A unified physical understanding of both passive and active droplet generation is beneficial for effectively developing new techniques meeting various demands arising from applications. Our review of passive approaches focuses on the characteristics and mechanisms of breakup modes of droplet generation occurring in microfluidic cross-flow, co-flow, flow-focusing, and step emulsification configurations. The review of active approaches covers the state-of-the-art techniques employing either external forces from electrical, magnetic and centrifugal fields or methods of modifying intrinsic properties of flows or fluids such as velocity, viscosity, interfacial tension, channel wettability, and fluid density, with a focus on their implementations and actuation mechanisms. Also included in this review is the contrast among different approaches of either passive or active nature.
Collapse
Affiliation(s)
- Pingan Zhu
- Department of Mechanical Engineering, The University of Hong Kong, Hong Kong, China. and HKU-Zhejiang Institute of Research and Innovation (HKU-ZIRI), 311300, Hangzhou, Zhejiang, China
| | - Liqiu Wang
- Department of Mechanical Engineering, The University of Hong Kong, Hong Kong, China. and HKU-Zhejiang Institute of Research and Innovation (HKU-ZIRI), 311300, Hangzhou, Zhejiang, China
| |
Collapse
|
6
|
Chong ZZ, Tan SH, Gañán-Calvo AM, Tor SB, Loh NH, Nguyen NT. Active droplet generation in microfluidics. LAB ON A CHIP 2016; 16:35-58. [PMID: 26555381 DOI: 10.1039/c5lc01012h] [Citation(s) in RCA: 121] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
The reliable generation of micron-sized droplets is an important process for various applications in droplet-based microfluidics. The generated droplets work as a self-contained reaction platform in droplet-based lab-on-a-chip systems. With the maturity of this platform technology, sophisticated and delicate control of the droplet generation process is needed to address increasingly complex applications. This review presents the state of the art of active droplet generation concepts, which are categorized according to the nature of the induced energy. At the liquid/liquid interface, an energy imbalance leads to instability and droplet breakup.
Collapse
Affiliation(s)
- Zhuang Zhi Chong
- School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798, Singapore
| | - Say Hwa Tan
- Queensland Micro- and Nanotechnology Centre, Griffith University, 170 Kessels Road QLD 4111, Brisbane, Australia.
| | - Alfonso M Gañán-Calvo
- Depto. de Ingeniería Aeroespacial y Mecánica de Fluidos, Universidad de Sevilla, E-41092 Sevilla, Spain.
| | - Shu Beng Tor
- School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798, Singapore
| | - Ngiap Hiang Loh
- School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798, Singapore
| | - Nam-Trung Nguyen
- Queensland Micro- and Nanotechnology Centre, Griffith University, 170 Kessels Road QLD 4111, Brisbane, Australia.
| |
Collapse
|
7
|
Ko YG, Lee HJ, Park YS, Woo JW, Choi US. The mixing effect of amine and carboxyl groups on electrorheological properties and its analysis by in situ FT-IR under an electric field. Phys Chem Chem Phys 2013; 15:16527-32. [PMID: 23945542 DOI: 10.1039/c3cp51907d] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Herein, the mixing effect of amine and carboxyl groups on electrorheological (ER) properties has been presented with the chitosan and alginic acid dispersed suspensions. Chitosan (for the amine group) and alginic acid (for the carboxyl group) are used to investigate the mixing effect of the amine and carboxyl groups on ER properties with the control of their mixing ratio in the silicone oil. The surface-chemical structure of the mixture of the chitosan and alginic acid particles in the silicone oil is demonstrated by in situ Fourier transform infrared (FT-IR) spectroscopy at various electric fields for the first time. This study focuses on whether the mixture of chemical groups in the ER fluid can promote ER properties or not, and in situ FT-IR analysis of the interface between ER particles in the silicone oil at various DC electric fields. The ER fluids exhibited the increase of the yield stress values with the increase of the counter group addition up to the weight ratio of 50 : 50 (chitosan : alginic acid). A noteworthy result is that the mixing effect of the amine and carboxyl groups resulting in enhanced ER properties is clearly proved. In the in situ FT-IR study, the complex form of amine and carboxyl groups of particles in the ER fluid was confirmed under the electric field.
Collapse
Affiliation(s)
- Young Gun Ko
- Center for Urban Energy Systems, Korea Institute of Science and Technology, Hwarangno 14-gil 5, Seongbuk-gu, Seoul 136-791, Korea.
| | | | | | | | | |
Collapse
|
8
|
Ko YG, Lee HJ, Chun YJ, Choi US, Yoo KP. Positive and negative electrorheological response of alginate salts dispersed suspensions under electric field. ACS APPLIED MATERIALS & INTERFACES 2013; 5:1122-1130. [PMID: 23336370 DOI: 10.1021/am302891w] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Electrorheological (ER) effects of alginic acid and alginate salts (Na(+) alginate, NH(4)(+) alginate, and Ca(2+) alginate) dispersed suspensions were investigated under DC electric fields. A noteworthy result is that the Ca(2+) alginate dispersed suspension showed negative electrorheological effects under electric fields while the other suspensions exhibited positive electrorheological effects. It is the first time that the negative ER effect is obtained with the biomacromolecule. Interestingly, at the DC electric fields, the electromigration of particles to two electrodes was observed in the negative ER fluid, while the particles-bridges formed between two electrodes in the case of the positive ER fluid. In conclusion, the specific salt type of biomacromolecules could be suitable ER particles for negative ER suspension. We believe that our study can present a new way for the development of the biocompatible and eco-friendly negative ER fluids.
Collapse
Affiliation(s)
- Young Gun Ko
- Center for Urban Energy Systems, Korea Institute of Science and Technology, Hwarangno 14-gil 5, Seongbuk-gu, Seoul 136-791, Korea
| | | | | | | | | |
Collapse
|
9
|
Valassis DT, Dodde RE, Esphuniyani B, Fowlkes JB, Bull JL. Microbubble transport through a bifurcating vessel network with pulsatile flow. Biomed Microdevices 2012; 14:131-43. [PMID: 21964559 PMCID: PMC6839772 DOI: 10.1007/s10544-011-9591-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Motivated by two-phase microfluidics and by the clinical applications of air embolism and a developmental gas embolotherapy technique, experimental and theoretical models of microbubble transport in pulsatile flow are presented. The one-dimensional time-dependent theoretical model is developed from an unsteady Bernoulli equation that has been modified to include viscous and unsteady effects. Results of both experiments and theory show that roll angle (the angle the plane of the bifurcating network makes with the horizontal) is an important contributor to bubble splitting ratio at each bifurcation within the bifurcating network. When compared to corresponding constant flow, pulsatile flow was shown to produce insignificant changes to the overall splitting ratio of the bubble despite the order one Womersley numbers, suggesting that bubble splitting through the vasculature could be modeled adequately with a more modest constant flow model. However, bubble lodging was affected by the flow pulsatility, and the effects of pulsatile flow were evident in the dependence of splitting ratio of bubble length. The ability of bubbles to remain lodged after reaching a steady state in the bifurcations is promising for the effectiveness of gas embolotherapy to occlude blood flow to tumors, and indicates the importance of understanding where lodging will occur in air embolism. The ability to accurately predict the bubble dynamics in unsteady flow within a bifurcating network is demonstrated and suggests the potential for bubbles in microfluidics devices to encode information in both steady and unsteady aspects of their dynamics.
Collapse
Affiliation(s)
- Doug T Valassis
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109-2110, USA
| | | | | | | | | |
Collapse
|
10
|
Seemann R, Brinkmann M, Pfohl T, Herminghaus S. Droplet based microfluidics. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2012; 75:016601. [PMID: 22790308 DOI: 10.1088/0034-4885/75/1/016601] [Citation(s) in RCA: 488] [Impact Index Per Article: 40.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Droplet based microfluidics is a rapidly growing interdisciplinary field of research combining soft matter physics, biochemistry and microsystems engineering. Its applications range from fast analytical systems or the synthesis of advanced materials to protein crystallization and biological assays for living cells. Precise control of droplet volumes and reliable manipulation of individual droplets such as coalescence, mixing of their contents, and sorting in combination with fast analysis tools allow us to perform chemical reactions inside the droplets under defined conditions. In this paper, we will review available drop generation and manipulation techniques. The main focus of this review is not to be comprehensive and explain all techniques in great detail but to identify and shed light on similarities and underlying physical principles. Since geometry and wetting properties of the microfluidic channels are crucial factors for droplet generation, we also briefly describe typical device fabrication methods in droplet based microfluidics. Examples of applications and reaction schemes which rely on the discussed manipulation techniques are also presented, such as the fabrication of special materials and biophysical experiments.
Collapse
Affiliation(s)
- Ralf Seemann
- Experimental Physics, Saarland University, D-66123 Saarbrücken, Germany.
| | | | | | | |
Collapse
|
11
|
Electrorheological Fluid and Its Applications in Microfluidics. MICROFLUIDICS 2011; 304:91-115. [DOI: 10.1007/128_2011_148] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
|
12
|
Wang L, Zhang M, Li J, Gong X, Wen W. Logic control of microfluidics with smart colloid. LAB ON A CHIP 2010; 10:2869-2874. [PMID: 20882229 DOI: 10.1039/c0lc00003e] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
We report the successful realization of a microfluidic chip with switching and corresponding inverting functionalities. The chips are identical logic control components incorporating a type of smart colloid, giant electrorheological fluid (GERF), which possesses reversible characteristics via a liquid-solid phase transition under external electric field. Two pairs of electrodes embedded on the sides of two microfluidic channels serve as signal input and output, respectively. One, located in the GERF micro-channel is used to control the flow status of GERF, while another one in the ither micro-fluidic channel is used to detect the signal generated with a passing-by droplet (defined as a signal droplet). Switching of the GERF from the suspended state (off-state) to the flowing state (on-state) or vice versa in the micro-channel is controlled by the appearance of signal droplets whenever they pass through the detection electrode. The output on-off signals can be easily demonstrated, clearly matching with GERF flow status. Our results show that such a logic switch is also a logic IF gate, while its inverter functions as a NOT gate.
Collapse
Affiliation(s)
- Limu Wang
- Nano Science and Nano Technology program, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong
| | | | | | | | | |
Collapse
|
13
|
Hong J, Choi M, Edel JB, deMello AJ. Passive self-synchronized two-droplet generation. LAB ON A CHIP 2010; 10:2702-9. [PMID: 20717573 DOI: 10.1039/c005136e] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
We describe the use of two passive components to achieve controllable and alternating droplet generation in a microfluidic device. The approach overcomes the problems associated with irregularities in channel dimensions and fluid flow rates, and allows precise pairing of alternating droplets in a high-throughput manner. We study droplet generation and self-synchronization in a quantitative fashion by using high-speed image analysis.
Collapse
Affiliation(s)
- Jongin Hong
- Department of Chemistry, Imperial College London, South Kensington, London, SW7 2AZ, UK
| | | | | | | |
Collapse
|