1
|
Gong L, Lin Y. Microfluidics in smart food safety. ADVANCES IN FOOD AND NUTRITION RESEARCH 2024; 111:305-354. [PMID: 39103216 DOI: 10.1016/bs.afnr.2024.06.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/07/2024]
Abstract
The evolution of food safety practices is crucial in addressing the challenges posed by a growing global population and increasingly complex food supply chains. Traditional methods are often labor-intensive, time-consuming, and susceptible to human error. This chapter explores the transformative potential of integrating microfluidics into smart food safety protocols. Microfluidics, involving the manipulation of small fluid volumes within microscale channels, offers a sophisticated platform for developing miniaturized devices capable of complex tasks. Combined with sensors, actuators, big data analytics, artificial intelligence, and the Internet of Things, smart microfluidic systems enable real-time data acquisition, analysis, and decision-making. These systems enhance control, automation, and adaptability, making them ideal for detecting contaminants, pathogens, and chemical residues in food products. The chapter covers the fundamentals of microfluidics, its integration with smart technologies, and its applications in food safety, addressing the challenges and future directions in this field.
Collapse
Affiliation(s)
- Liyuan Gong
- Department of Mechanical, Industrial and Systems Engineering, University of Rhode Island, Kingston, RI, United States
| | - Yang Lin
- Department of Mechanical, Industrial and Systems Engineering, University of Rhode Island, Kingston, RI, United States.
| |
Collapse
|
2
|
Arndt NB, Adolphs T, Arlinghaus HF, Heidrich B, Ravoo BJ. Arylazopyrazole-Modified Thiolactone Acrylate Copolymer Brushes for Tuneable and Photoresponsive Wettability of Glass Surfaces. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2023; 39:5342-5351. [PMID: 37011284 DOI: 10.1021/acs.langmuir.2c03400] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
Photoswitches have long been employed in coatings for surfaces and substrates to harness light as a versatile stimulus to induce responsive behavior. We previously demonstrated the viability of arylazopyrazole (AAP) as a photoswitch in self-assembled monolayers (SAMs) on silicon and glass surfaces for photoresponsive wetting applications. We now aim to transfer the excellent photophysical properties of AAPs to polymer brush coatings. Compared to SAMs, polymer brushes offer enhanced stability and an increase of the thickness and density of the functional organic layer. In this work, we present thiolactone acrylate copolymer brushes which can be post-modified with AAP amines as well as hydrophobic acrylates, making use of the unique chemistry of the thiolactones. This strategy enables photoresponsive wetting with a tuneable range of contact angle change on glass substrates. We show the successful synthesis of thiolactone hydroxyethyl acrylate copolymer brushes by means of surface-initiated atom-transfer radical polymerization with the option to either prepare homogeneous brushes or to prepare micrometer-sized brush patterns by microcontact printing. The polymer brushes were analyzed by atomic force microscopy, time-of-flight secondary ion spectrometry, and X-ray photoelectron spectroscopy. Photoresponsive behavior imparted to the brushes by means of post-modification with AAP is monitored by UV/vis spectroscopy, and wetting behavior of homogeneous brushes is measured by static and dynamic contact angle measurements. The brushes show an average change in static contact angle of around 13° between E and Z isomer of the AAP photoswitch for at least five cycles, while the range of contact angle change can be fine-tuned between 53.5°/66.5° (E/Z) and 81.5°/94.8° (E/Z) by post-modification with hydrophobic acrylates.
Collapse
Affiliation(s)
- Niklas B Arndt
- Center for Soft Nanoscience and Organic Chemistry Institute, University of Münster, Busso-Peus-Straße 10, 48149 Münster, Germany
| | - Thorsten Adolphs
- Center for Soft Nanoscience and Physics Institute, University of Münster, Wilhelm-Klemm-Straße 10, 48149 Münster, Germany
| | - Heinrich F Arlinghaus
- Center for Soft Nanoscience and Physics Institute, University of Münster, Wilhelm-Klemm-Straße 10, 48149 Münster, Germany
| | - Bastian Heidrich
- MEET Battery Research Center, University of Münster, Corrensstraße 46, 48149 Münster, Germany
- Institute of Physical Chemistry, University of Münster, Corrensstraße 29, 48149 Münster, Germany
| | - Bart Jan Ravoo
- Center for Soft Nanoscience and Organic Chemistry Institute, University of Münster, Busso-Peus-Straße 10, 48149 Münster, Germany
| |
Collapse
|
3
|
Wang S, Zhou R, Hou Y, Wang M, Hou X. Photochemical effect driven fluid behavior control in microscale pores and channels. CHINESE CHEM LETT 2022. [DOI: 10.1016/j.cclet.2021.11.095] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
|
4
|
Li S, Zhang R, Zhang G, Shuai L, Chang W, Hu X, Zou M, Zhou X, An B, Qian D, Liu Z. Microfluidic manipulation by spiral hollow-fibre actuators. Nat Commun 2022; 13:1331. [PMID: 35288561 PMCID: PMC8921237 DOI: 10.1038/s41467-022-29088-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Accepted: 02/16/2022] [Indexed: 12/31/2022] Open
Abstract
A microfluidic manipulation system that can sense a liquid and control its flow is highly desirable. However, conventional sensors and motors have difficulty fitting the limited space in microfluidic devices; moreover, fast sensing and actuation are required because of the fast liquid flow in the hollow fibre. In this study, fast torsional and tensile actuators were developed using hollow fibres employing spiral nonlinear stress, which can sense the fluid temperature and sort the fluid into the desired vessels. The fluid-driven actuation exhibited a highly increased response speed (27 times as fast as that of air-driven actuation) and increased power density (90 times that of an air-driven solid fibre actuator). A 0.5 K fluid temperature fluctuation produced a 20° rotation of the hollow fibre. These high performances originated from increments in both heat transfer and the average bias angle, which was understood through theoretical analysis. This work provides a new design strategy for intelligent microfluidics and inspiration for soft robots and smart devices for biological, optical, or magnetic applications.
Collapse
Affiliation(s)
- Sitong Li
- State Key Laboratory of Medicinal Chemical Biology, College of Chemistry and College of Pharmacy, Key Laboratory of Functional Polymer Materials, Frontiers Science Center for New Organic Matter, Nankai University, Tianjin, 300071, China
| | - Rui Zhang
- Department of Mechanical Engineering, University of Texas at Dallas, Richardson, TX, 75080, USA
| | - Guanghao Zhang
- State Key Laboratory of Medicinal Chemical Biology, College of Chemistry and College of Pharmacy, Key Laboratory of Functional Polymer Materials, Frontiers Science Center for New Organic Matter, Nankai University, Tianjin, 300071, China
| | - Luyizheng Shuai
- State Key Laboratory of Medicinal Chemical Biology, College of Chemistry and College of Pharmacy, Key Laboratory of Functional Polymer Materials, Frontiers Science Center for New Organic Matter, Nankai University, Tianjin, 300071, China
| | - Wang Chang
- State Key Laboratory of Medicinal Chemical Biology, College of Chemistry and College of Pharmacy, Key Laboratory of Functional Polymer Materials, Frontiers Science Center for New Organic Matter, Nankai University, Tianjin, 300071, China
| | - Xiaoyu Hu
- State Key Laboratory of Medicinal Chemical Biology, College of Chemistry and College of Pharmacy, Key Laboratory of Functional Polymer Materials, Frontiers Science Center for New Organic Matter, Nankai University, Tianjin, 300071, China
| | - Min Zou
- State Key Laboratory of Medicinal Chemical Biology, College of Chemistry and College of Pharmacy, Key Laboratory of Functional Polymer Materials, Frontiers Science Center for New Organic Matter, Nankai University, Tianjin, 300071, China
| | - Xiang Zhou
- State Key Laboratory of Medicinal Chemical Biology, College of Chemistry and College of Pharmacy, Key Laboratory of Functional Polymer Materials, Frontiers Science Center for New Organic Matter, Nankai University, Tianjin, 300071, China
| | - Baigang An
- School of Chemical Engineering, University of Science and Technology Liaoning, Anshan, 114051, China
| | - Dong Qian
- Department of Mechanical Engineering, University of Texas at Dallas, Richardson, TX, 75080, USA
| | - Zunfeng Liu
- State Key Laboratory of Medicinal Chemical Biology, College of Chemistry and College of Pharmacy, Key Laboratory of Functional Polymer Materials, Frontiers Science Center for New Organic Matter, Nankai University, Tianjin, 300071, China.
| |
Collapse
|
5
|
Arndt NB, Schlüter F, Böckmann M, Adolphs T, Arlinghaus HF, Doltsinis NL, Ravoo BJ. Self-Assembled Monolayers of Arylazopyrazoles on Glass and Silicon Oxide: Photoisomerization and Photoresponsive Wettability. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:735-742. [PMID: 34989243 DOI: 10.1021/acs.langmuir.1c02651] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Surface coatings that respond to external influences and change their physical properties upon application of external stimuli are of great interest, with light being a particularly desirable choice. Photoswitches such as azobenzenes have been employed in a range of photoresponsive coatings. One striking change in physical property of many photoresponsive coatings is their responsive wettability upon illumination. In this work, we present photoswitchable self-assembled monolayers based on arylazopyrazoles (AAPs). In solution, AAPs offer significant improvements in terms of the photostationary state, thermal stability, and fatigue resistance. The AAP photoswitch is coupled to triethoxysilanes for an easy, one-step functionalization of glass and silicon oxide surfaces. We show the synthesis of AAP-based silanes and the successful surface functionalization, and we confirm the excellent photoswitchability of the AAPs in a self-assembled monolayer upon alternating irradiation with UV (365 nm) and green (520 nm) light. The self-assembled monolayers are investigated by UV/vis spectroscopy, X-ray photoelectron spectroscopy (XPS), time-of-flight secondary ion mass spectrometry (ToF-SIMS), and contact angle goniometry. We furthermore investigate the effect of substitution of the AAPs on the photoresponsive wetting behavior and compare this with density functional theory (DFT) calculations of the dipole moments of the AAPs.
Collapse
Affiliation(s)
- Niklas B Arndt
- Center for Soft Nanoscience and Organic Chemistry Institute, Westfälische Wilhelms-Universität Münster, Busso-Peus Straße 10, 48149 Münster, Germany
| | - Friederike Schlüter
- Center for Soft Nanoscience and Organic Chemistry Institute, Westfälische Wilhelms-Universität Münster, Busso-Peus Straße 10, 48149 Münster, Germany
| | - Marcus Böckmann
- Center for Soft Nanoscience and Institute of Solid State Theory, Westfälische Wilhelms-Universität Münster, Wilhelm-Klemm-Straße 10, 48149 Münster, Germany
| | - Thorsten Adolphs
- Center for Soft Nanoscience and Physics Institute, Westfälische Wilhelms-Universität Münster, Wilhelm-Klemm-Straße 10, 48149 Münster, Germany
| | - Heinrich F Arlinghaus
- Center for Soft Nanoscience and Physics Institute, Westfälische Wilhelms-Universität Münster, Wilhelm-Klemm-Straße 10, 48149 Münster, Germany
| | - Nikos L Doltsinis
- Center for Soft Nanoscience and Institute of Solid State Theory, Westfälische Wilhelms-Universität Münster, Wilhelm-Klemm-Straße 10, 48149 Münster, Germany
| | - Bart Jan Ravoo
- Center for Soft Nanoscience and Organic Chemistry Institute, Westfälische Wilhelms-Universität Münster, Busso-Peus Straße 10, 48149 Münster, Germany
| |
Collapse
|
6
|
Xia HM, Wu JW, Zheng JJ, Zhang J, Wang ZP. Nonlinear microfluidics: device physics, functions, and applications. LAB ON A CHIP 2021; 21:1241-1268. [PMID: 33877234 DOI: 10.1039/d0lc01120g] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The microfluidic flow is typically laminar due to the dominant viscous effects. At Reynolds numbers far below 1 (Re ≪ 1), the fluid inertia can be neglected. For the steady flow of incompressible Newtonian fluids, it approaches linear Stokes flow. At intermediate Re, there exists a weak-inertia flow regime where secondary flows such as Dean vortices are accessible for microfluidic manipulations. Apart from the fluid inertia, other nonlinear factors such as the non-Newtonian fluid properties, concurrent flow of dissimilar fluids, compliant fluidic structures and stimuli-responsive materials can also cause intriguing flow behaviours. Through proper designs, they can be applied for a variety of microfluidic components including mixers, valves, oscillators, stabilizers and auto-regulators etc., greatly enriching the microfluidic flow control and manipulation strategies. Due to its unique working characteristics and advantages, nonlinear microfluidics has increasingly attracted extensive attention. This review presents a systematic survey on this subject. The designs of typical nonlinear microfluidic devices, their working mechanisms, key applications, and the perspective of their future developments will be discussed. The nonlinear microfluidic techniques are believed to play an essential role in the next generation of highly-integrated, automated, and intelligent microfluidics.
Collapse
Affiliation(s)
- H M Xia
- School of Mechanical Engineering, Nanjing University of Science and Technology, Nanjing 210094, P. R. China.
| | | | | | | | | |
Collapse
|
7
|
Tan CME, Dizon GV, Chen SH, Venault A, Chou YN, Tayo L, Chang Y. Temperature-triggered attachment and detachment of general human bio-foulants on zwitterionic polydimethylsiloxane. J Mater Chem B 2020; 8:8853-8863. [PMID: 33026392 DOI: 10.1039/d0tb01478h] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Biofouling has long been a problem for biomaterials, so being able to control the fouling on the surface of a biomaterial would be ideal. In this study a copolymer system was designed comprising three moieties: an epoxy containing group, glycidyl methacrylate (GMA); a thermoresponsive segment, N-isopropylacrylamide (NIPAAm); and an antifouling zwitterionic unit, sulfobetaine methacrylate (SBMA). The copolymers (pGSN), synthesized via free radical polymerization with these 3 moieties, were then grafted onto polydimethylsiloxane (PDMS). The presence of a critical temperature for both the copolymers and the coated PDMS was evidenced by particle size and contact angle measurements. The coated PDMS exhibited controllable temperature-dependent antifouling behaviors and stimuli-responsive phase characteristics in the presence of salts. The interactions of the coated PDMS with biomolecules were tested via attachment of fibrinogen protein, platelets, human whole blood, and tumor cells (HT1080). The attachment and detachment of these biomolecules were studied at different temperatures. Exposed hydrophobic domains of thermoresponsive NIPAAm-rich pGSN containing NIPAAm at 56 mol% generally allows molecular and cellular attachment on the PDMS surface at 37 °C. On the other hand, the coated PDMS with a relatively high content of SBMA (>41 mol%) in the copolymer started to exhibit fouling resistance and lower the thermoresponsive properties. Interestingly, the incorporation of zwitterionic SBMA units into the copolymers was found to accelerate the hydration of the PDMS surfaces and resulted in biomolecular and cellular detachment at 25 °C, which is comparable to the detachment at 4 °C. This modified surface behavior is found to be consistent through all biofouling tests.
Collapse
Affiliation(s)
- Christian Martin E Tan
- School of Chemical, Biological and Materials Engineering and Sciences, Mapúa University, Intramuros, Manila, 1002, Philippines
| | | | | | | | | | | | | |
Collapse
|
8
|
Yu N, Liu Y, Ji B, Wang S, Chen Y, Sun T, Zhang J, Yang B. High-sensitivity microliter blood pressure sensors based on patterned micro-nanostructure arrays. LAB ON A CHIP 2020; 20:1554-1561. [PMID: 32334425 DOI: 10.1039/d0lc00063a] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Herein we present a micro-nanostructure integrated liquid pressure sensor, which features an ultra-high sensitivity of 16.71 mbar-1, a low-pressure regime of 2 mbar, a trace sample volume of less than 1.3 μL and a visible display element. The measurable pressure ranges of the sensors include not only from micro-scale fluids to bulk liquids but also from hydraulic pressures to blood pressures, opening a window for liquid pressure sensing in lab-on-chip platforms, point-of-care diagnostics, and even robotics.
Collapse
Affiliation(s)
- Nianzuo Yu
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, 130012, P. R. China.
| | | | | | | | | | | | | | | |
Collapse
|
9
|
Zuo Y, Zheng L, Zhao C, Liu H. Micro-/Nanostructured Interface for Liquid Manipulation and Its Applications. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2020; 16:e1903849. [PMID: 31482672 DOI: 10.1002/smll.201903849] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Revised: 08/12/2019] [Indexed: 05/09/2023]
Abstract
Understanding the relationship between liquid manipulation and micro-/nanostructured interfaces has gained much attention due to the wide potential applications in many fields, such as chemical and biomedical assays, environmental protection, industry, and even daily life. Much work has been done to construct various materials with interfacial liquid manipulation abilities, leading to a range of interesting applications. Herein, different fabrication methods from the top-down approach to the bottom-up approach and subsequent surface modifications of micro-/nanostructured interfaces are first introduced. Then, interactions between the surface and liquid, including liquid wetting, liquid transportation, and a number of corresponding models, together with the definition of hydrophilic/hydrophobic, oleophilic/olephobic, the definition and mechanism of superwetting, including superhydrophobicity, superhydrophilicity, and superoleophobicity, are presented. The micro-/nanostructured interface, with major applications in self-cleaning, antifogging, anti-icing, anticorrosion, drag-reduction, oil-water separation, water collection, droplet (micro)array, and surface-directed liquid transport, is summarized, and the mechanisms underlying each application are discussed. Finally, the remaining challenges and future perspectives in this area are included.
Collapse
Affiliation(s)
- Yinxiu Zuo
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, 210096, China
| | - Liuzheng Zheng
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, 210096, China
| | - Chao Zhao
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, 210096, China
| | - Hong Liu
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, 210096, China
| |
Collapse
|
10
|
Wang S, Yang X, Wu F, Min L, Chen X, Hou X. Inner Surface Design of Functional Microchannels for Microscale Flow Control. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2020; 16:e1905318. [PMID: 31793747 DOI: 10.1002/smll.201905318] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Revised: 11/03/2019] [Indexed: 05/05/2023]
Abstract
Fluidic flow behaviors in microfluidics are dominated by the interfaces created between the fluids and the inner surface walls of microchannels. Microchannel inner surface designs, including the surface chemical modification, and the construction of micro-/nanostructures, are good examples of manipulating those interfaces between liquids and surfaces through tuning the chemical and physical properties of the inner walls of the microchannel. Therefore, the microchannel inner surface design plays critical roles in regulating microflows to enhance the capabilities of microfluidic systems for various applications. Most recently, the rapid progresses in micro-/nanofabrication technologies and fundamental materials have also made it possible to integrate increasingly complex chemical and physical surface modification strategies with the preparation of microchannels in microfluidics. Besides, a wave of researches focusing on the ideas of using liquids as dynamic surface materials is identified, and the unique characteristics endowed with liquid-liquid interfaces have revealed that the interesting phenomena can extend the scope of interfacial interactions determining microflow behaviors. This review extensively discusses the microchannel inner surface designs for microflow control, especially evaluates them from the perspectives of the interfaces resulting from the inner surface designs. In addition, prospective opportunities for the development of surface designs of microchannels, and their applications are provided with the potential to attract scientific interest in areas related to the rapid development and applications of various microchannel systems.
Collapse
Affiliation(s)
- Shuli Wang
- College of Chemistry and Chemical Engineering and State Key Laboratory of Physical Chemistry of Solid Surfaces, Xiamen University, Xiamen, 361005, China
- Collaborative Innovation Center of Chemistry for Energy Materials, Xiamen University, Xiamen, 361005, China
| | - Xian Yang
- College of Chemistry and Chemical Engineering and State Key Laboratory of Physical Chemistry of Solid Surfaces, Xiamen University, Xiamen, 361005, China
| | - Feng Wu
- Bionic and Soft Matter Research Institute, College of Physical Science and Technology, Xiamen University, Xiamen, 361005, China
- Fujian Provincial Key Laboratory for Soft Functional Materials Research, Xiamen University, Xiamen, 361005, China
| | - Lingli Min
- College of Chemistry and Chemical Engineering and State Key Laboratory of Physical Chemistry of Solid Surfaces, Xiamen University, Xiamen, 361005, China
| | - Xinyu Chen
- College of Chemistry and Chemical Engineering and State Key Laboratory of Physical Chemistry of Solid Surfaces, Xiamen University, Xiamen, 361005, China
| | - Xu Hou
- College of Chemistry and Chemical Engineering and State Key Laboratory of Physical Chemistry of Solid Surfaces, Xiamen University, Xiamen, 361005, China
- Collaborative Innovation Center of Chemistry for Energy Materials, Xiamen University, Xiamen, 361005, China
- Bionic and Soft Matter Research Institute, College of Physical Science and Technology, Xiamen University, Xiamen, 361005, China
- Fujian Provincial Key Laboratory for Soft Functional Materials Research, Xiamen University, Xiamen, 361005, China
| |
Collapse
|
11
|
Wang S, Liu Y, Ge P, Kan Q, Yu N, Wang J, Nan J, Ye S, Zhang J, Xu W, Yang B. Colloidal lithography-based fabrication of highly-ordered nanofluidic channels with an ultra-high surface-to-volume ratio. LAB ON A CHIP 2018; 18:979-988. [PMID: 29485661 DOI: 10.1039/c7lc01326d] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
This article shows a new strategy for the fabrication of nanofluidics based on nanoscale gaps in nanopillar arrays. Silicon nanopillar arrays are prepared in a designed position by combining conventional photolithography with colloidal lithography. The nanogaps between the pillars are used as nanochannels for the connection of two polydimethylsiloxane-based microchannels in microfluidics. The gap between neighbouring nanopillars can be accurately controlled by changing the size of initial colloidal spheres and by an etching process, which further determines the dimensions of the nanochannels. At a low ionic strength, the surface charge-governed ion transportation shows that the nanochannels possess the same electrokinetic properties as typical nanofluidics. Benefiting from the advantage of photolithography, large-area nanochannel arrays can be prepared in a parallel manner. Due to the perm-selectivity of the nanochannels, the nanofluidic chips can be used to preconcentrate low concentration samples. The large-area ordered nanostructures preserve their high-throughput property and large surface-to-volume ratio, which shows their great potential in the development of nanofluidics and their applications, such as in the separation of small molecules, energy conversion, etc.
Collapse
Affiliation(s)
- Shuli Wang
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, 130012, P. R. China.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
12
|
Li Y, He L, Zhang X, Zhang N, Tian D. External-Field-Induced Gradient Wetting for Controllable Liquid Transport: From Movement on the Surface to Penetration into the Surface. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2017; 29:1703802. [PMID: 29052911 DOI: 10.1002/adma.201703802] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2017] [Revised: 09/02/2017] [Indexed: 06/07/2023]
Abstract
External-field-responsive liquid transport has received extensive research interest owing to its important applications in microfluidic devices, biological medical, liquid printing, separation, and so forth. To realize different levels of liquid transport on surfaces, the balance of the dynamic competing processes of gradient wetting and dewetting should be controlled to achieve good directionality, confined range, and selectivity of liquid wetting. Here, the recent progress in external-field-induced gradient wetting is summarized for controllable liquid transport from movement on the surface to penetration into the surface, particularly for liquid motion on, patterned wetting into, and permeation through films on superwetting surfaces with external field cooperation (e.g., light, electric fields, magnetic fields, temperature, pH, gas, solvent, and their combinations). The selected topics of external-field-induced liquid transport on the different levels of surfaces include directional liquid motion on the surface based on the wettability gradient under an external field, partial entry of a liquid into the surface to achieve patterned surface wettability for printing, and liquid-selective permeation of the film for separation. The future prospects of external-field-responsive liquid transport are also discussed.
Collapse
Affiliation(s)
- Yan Li
- Beijing Advanced Innovation Center for Biomedical Engineering, School of Chemistry, Beihang University, Beijing, 100191, P. R. China
| | - Linlin He
- Beijing Advanced Innovation Center for Biomedical Engineering, School of Chemistry, Beihang University, Beijing, 100191, P. R. China
| | - Xiaofang Zhang
- School of Mathematics and Physics, University of Science & Technology Beijing, Beijing, 100083, P. R. China
| | - Na Zhang
- Beijing Advanced Innovation Center for Biomedical Engineering, School of Chemistry, Beihang University, Beijing, 100191, P. R. China
| | - Dongliang Tian
- Beijing Advanced Innovation Center for Biomedical Engineering, School of Chemistry, Beihang University, Beijing, 100191, P. R. China
| |
Collapse
|