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Kamranikia K, Dominici S, Keller M, Kube N, Mougin K, Spangenberg A. Very High-Aspect-Ratio Polymeric Micropillars Made by Two-Photon Polymerization. MICROMACHINES 2023; 14:1602. [PMID: 37630138 PMCID: PMC10456646 DOI: 10.3390/mi14081602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Revised: 08/02/2023] [Accepted: 08/13/2023] [Indexed: 08/27/2023]
Abstract
Polymeric micropillars with a high-aspect-ratio (HAR) are of interest for a wide range of applications, including drug delivery and the micro-electro-mechanical field. While molding is the most common method for fabricating HAR microstructures, it is affected by challenges related to demolding the final structure. In this study, we present very HAR micropillars using two-photon polymerization (TPP), an established technique for creating complex 3D microstructures. Polymeric micropillars with HARs fabricated by TPP often shrink and collapse during the development process. This is due to the lack of mechanical stability of micropillars against capillary forces primarily acting during the fabrication process when the solvent evaporates. Here, we report different parameters that have been optimized to overcome the capillary force. These include surface modification of the substrate, fabrication parameters such as laser power, exposure time, the pitch distance between the pillars, and the length of the pillars. On account of adopting these techniques, we were able to fabricate micropillars with a very HAR up to 80.
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Affiliation(s)
- Keynaz Kamranikia
- Institut de Science des Matériaux de Mulhouse (IS2M), CNRS-UMR 7361, Université de Haute-Alsace, 15 rue Jean Starcky, 68057 Mulhouse, France; (K.K.); (S.D.); (M.K.); (N.K.); (K.M.)
- Université de Strasbourg, 67000 Strasbourg, France
| | - Sébastien Dominici
- Institut de Science des Matériaux de Mulhouse (IS2M), CNRS-UMR 7361, Université de Haute-Alsace, 15 rue Jean Starcky, 68057 Mulhouse, France; (K.K.); (S.D.); (M.K.); (N.K.); (K.M.)
- Université de Strasbourg, 67000 Strasbourg, France
| | - Marc Keller
- Institut de Science des Matériaux de Mulhouse (IS2M), CNRS-UMR 7361, Université de Haute-Alsace, 15 rue Jean Starcky, 68057 Mulhouse, France; (K.K.); (S.D.); (M.K.); (N.K.); (K.M.)
- Université de Strasbourg, 67000 Strasbourg, France
| | - Niklas Kube
- Institut de Science des Matériaux de Mulhouse (IS2M), CNRS-UMR 7361, Université de Haute-Alsace, 15 rue Jean Starcky, 68057 Mulhouse, France; (K.K.); (S.D.); (M.K.); (N.K.); (K.M.)
- Université de Strasbourg, 67000 Strasbourg, France
| | - Karine Mougin
- Institut de Science des Matériaux de Mulhouse (IS2M), CNRS-UMR 7361, Université de Haute-Alsace, 15 rue Jean Starcky, 68057 Mulhouse, France; (K.K.); (S.D.); (M.K.); (N.K.); (K.M.)
- Université de Strasbourg, 67000 Strasbourg, France
| | - Arnaud Spangenberg
- Institut de Science des Matériaux de Mulhouse (IS2M), CNRS-UMR 7361, Université de Haute-Alsace, 15 rue Jean Starcky, 68057 Mulhouse, France; (K.K.); (S.D.); (M.K.); (N.K.); (K.M.)
- Université de Strasbourg, 67000 Strasbourg, France
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Gao P, MacKay I, Gruber A, Krantz J, Piccolo L, Lucchetta G, Pelaccia R, Orazi L, Masato D. Wetting Characteristics of Laser-Ablated Hierarchical Textures Replicated by Micro Injection Molding. MICROMACHINES 2023; 14:863. [PMID: 37421096 DOI: 10.3390/mi14040863] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 04/06/2023] [Accepted: 04/15/2023] [Indexed: 07/09/2023]
Abstract
Texturing can be used to functionalize the surface of plastic parts and, in particular, to modify the interaction with fluids. Wetting functionalization can be used for microfluidics, medical devices, scaffolds, and more. In this research, hierarchical textures were generated on steel mold inserts using femtosecond laser ablation to transfer on plastic parts surface via injection molding. Different textures were designed to study the effects of various hierarchical geometries on the wetting behavior. The textures are designed to create wetting functionalization while avoiding high aspect ratio features, which are complex to replicate and difficult to manufacture at scale. Nano-scale ripples were generated over the micro-scale texture by creating laser-induced periodic surface structures. The textured molds were then replicated by micro-injection molding using polypropylene and poly(methyl methacrylate). The static wetting behavior was investigated on steel inserts and molded parts and compared to the theoretical values obtained from the Cassie-Baxter and Wenzel models. The experimental results showed correlations between texture design, injection molding replication, and wetting properties. The wetting behavior on the polypropylene parts followed the Cassie-Baxter model, while for PMMA, a composite wetting state of Cassie-Baxter and Wenzel was observed.
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Affiliation(s)
- Peng Gao
- Plastics Engineering Department, University of Massachusetts Lowell, Lowell, MA 01854, USA
| | - Ian MacKay
- Plastics Engineering Department, University of Massachusetts Lowell, Lowell, MA 01854, USA
| | - Andrea Gruber
- Plastics Engineering Department, University of Massachusetts Lowell, Lowell, MA 01854, USA
| | - Joshua Krantz
- Plastics Engineering Department, University of Massachusetts Lowell, Lowell, MA 01854, USA
| | - Leonardo Piccolo
- Plastics Engineering Department, University of Massachusetts Lowell, Lowell, MA 01854, USA
- Department of Industrial Engineering, University of Padova, 35100 Padova, Italy
| | - Giovanni Lucchetta
- Department of Industrial Engineering, University of Padova, 35100 Padova, Italy
| | - Riccardo Pelaccia
- Department of Sciences and Methods for Engineering, University of Modena and Reggio Emilia, 41124 Reggio Emilia, Italy
| | - Leonardo Orazi
- Department of Sciences and Methods for Engineering, University of Modena and Reggio Emilia, 41124 Reggio Emilia, Italy
- EN&TECH, University of Modena and Reggio Emilia, 41124 Reggio Emilia, Italy
| | - Davide Masato
- Plastics Engineering Department, University of Massachusetts Lowell, Lowell, MA 01854, USA
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Puntsagdorj S, Koirala AR, Gombovanjil J, Khanh NN, Sung SD, Lee WI, Yoon KB. Increase in Photocurrent Density of WO 3 Photoanode by Placing a Layer of an Ordered Array of Mesoporous WO 3 Micropillars on Top of a WO 3 Sheet Layer. ACS APPLIED MATERIALS & INTERFACES 2022; 14:31838-31850. [PMID: 35792885 DOI: 10.1021/acsami.2c05107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
A facile stamping method was developed to assemble ordered arrays of mesoporous WO3 micropillars with uniform sizes, shapes, and lengths on F-doped tin oxide glass. Using this method, a series of WO3 heterostructural bilayer photoanodes consisting of an array of m-μm long ordered mesoporous WO3 micropillars at the top and the n-μm thick mesoporous WO3 plain sheet layer at the bottom (denoted as m/n) were prepared. Among them 2.5/7.5 displayed a steady state photocurrent density of 3.6 mA cm-2 at 1.23 V (vs RHE) under AM 1.5 (1 Sun), which is much higher than that of the plain 10-μm thick WO3 sheet (2.5 mA cm-2). This phenomenon occurs owing to the following six benefits: increases in charge carrier density, number of photogenerated electron, charge collection rate, thermodynamic feasibility for the vectorial charge transport from the outermost layer of the photoanode to the inner layer, the surface hydrophilicity, and the decrease in charge transfer resistance.
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Affiliation(s)
| | | | | | | | - Sang Do Sung
- Department of Chemistry, Inha University, 100 Inharo, Nam-gu, Incheon 22212, Korea
| | - Wan In Lee
- Department of Chemistry, Inha University, 100 Inharo, Nam-gu, Incheon 22212, Korea
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Logan Howard R, Wang Y, Allbritton NL. Use of liquid lithography to form in vitro intestinal crypts with varying microcurvature surrounding the stem cell niche. JOURNAL OF MICROMECHANICS AND MICROENGINEERING : STRUCTURES, DEVICES, AND SYSTEMS 2021; 31:125006. [PMID: 35241878 PMCID: PMC8887876 DOI: 10.1088/1361-6439/ac2d9c] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
BACKGROUND AND AIMS The role of the crypt microarchitecture and surrounding tissue curvature on intestinal stem/proliferative cell physiology is unknown. The utility of liquid lithography in creating polydimethylsiloxane (PDMS) micropillar stamps with controlled tip curvature was assessed. Using these stamps, the impact of microcurvature at the crypt base on intestinal cell and cytoskeletal behavior was studied. METHODS An SU-8 master mold as a support, polyols of varying surface energies as sacrificial liquids, and liquid PDMS as the solidifiable material were combined using liquid lithography to form PDMS micropillar arrays. Vapor phase deposition of organosilane onto the master mold was used to modify the surface energy of the master mold to shape the micropillar tips. Collagen was molded using the micropillar arrays forming a scaffold for culture of human primary colonic epithelial cells. Cell proliferation and cytoskeletal properties were assessed using fluorescent stains. RESULTS Liquid lithography using low surface energy polyols (<55 dynes/cm) generated convex-tipped PDMS micropillars, while polyols with higher surface energies (>55 dynes/cm) yielded concave-tipped PDMS micropillars. Gradients of octyltrichlorosilane deposition across a master mold with an array of microwells yielded a PDMS micropillar array with a range of tip curvatures. Human primary colonic epithelial cells cultured on micropillar-molded collagen scaffolds demonstrated a stem/proliferative cell compartment at the crypt base. Crypts with a convex base demonstrated significantly lower cell proliferation at the crypt base than that of cells in crypts with either flat or concave bases. Crypts with a convex base also displayed higher levels of G-actin activity compared to that of crypts with flat or concave bases. CONCLUSIONS Liquid lithography enabled creation of arrays of in vitro colonic crypts with programmable curvature. Primary cells at the crypt base sensed and responded to surface curvature by altering their proliferation and cytoskeletal properties.
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Affiliation(s)
- R Logan Howard
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
- Cystic Fibrosis and Pulmonary Diseases Research and Treatment Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Yuli Wang
- Department of Bioengineering, University of Washington, Seattle, Washington
| | - Nancy L Allbritton
- Department of Bioengineering, University of Washington, Seattle, Washington
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Chiappini C, Chen Y, Aslanoglou S, Mariano A, Mollo V, Mu H, De Rosa E, He G, Tasciotti E, Xie X, Santoro F, Zhao W, Voelcker NH, Elnathan R. Tutorial: using nanoneedles for intracellular delivery. Nat Protoc 2021; 16:4539-4563. [PMID: 34426708 DOI: 10.1038/s41596-021-00600-7] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Accepted: 06/30/2021] [Indexed: 02/08/2023]
Abstract
Intracellular delivery of advanced therapeutics, including biologicals and supramolecular agents, is complex because of the natural biological barriers that have evolved to protect the cell. Efficient delivery of therapeutic nucleic acids, proteins, peptides and nanoparticles is crucial for clinical adoption of emerging technologies that can benefit disease treatment through gene and cell therapy. Nanoneedles are arrays of vertical high-aspect-ratio nanostructures that can precisely manipulate complex processes at the cell interface, enabling effective intracellular delivery. This emerging technology has already enabled the development of efficient and non-destructive routes for direct access to intracellular environments and delivery of cell-impermeant payloads. However, successful implementation of this technology requires knowledge of several scientific fields, making it complex to access and adopt by researchers who are not directly involved in developing nanoneedle platforms. This presents an obstacle to the widespread adoption of nanoneedle technologies for drug delivery. This tutorial aims to equip researchers with the knowledge required to develop a nanoinjection workflow. It discusses the selection of nanoneedle devices, approaches for cargo loading and strategies for interfacing to biological systems and summarises an array of bioassays that can be used to evaluate the efficacy of intracellular delivery.
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Affiliation(s)
- Ciro Chiappini
- Centre for Craniofacial and Regenerative Biology, King's College London, London, UK.
- London Centre for Nanotechnology, King's College London, London, UK.
| | - Yaping Chen
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
- Melbourne Centre for Nanofabrication, Victorian Node of the Australian National Fabrication Facility, Clayton, Victoria, Australia
| | - Stella Aslanoglou
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
- Melbourne Centre for Nanofabrication, Victorian Node of the Australian National Fabrication Facility, Clayton, Victoria, Australia
- CSIRO Manufacturing, Clayton, Victoria, Australia
| | - Anna Mariano
- Center for Advanced Biomaterials for Healthcare, Istituto Italiano di Tecnologia, Naples, Italy
| | - Valentina Mollo
- Center for Advanced Biomaterials for Healthcare, Istituto Italiano di Tecnologia, Naples, Italy
| | - Huanwen Mu
- School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore, Singapore
| | - Enrica De Rosa
- Center for Musculoskeletal Regeneration, Orthopedics & Sports Medicine, Houston Methodist Research Institute, Houston, TX, USA
| | - Gen He
- State Key Laboratory of Optoelectronic Materials and Technologies, Guangdong Province Key Laboratory of Display Material and Technology, School of Electronics and Information Technology, Sun Yat-sen University, Guangzhou, China
| | - Ennio Tasciotti
- IRCCS San Raffaele Pisana Hospital, Rome, Italy
- San Raffaele University, Rome, Italy
- Sclavo Pharma, Siena, Italy
| | - Xi Xie
- State Key Laboratory of Optoelectronic Materials and Technologies, Guangdong Province Key Laboratory of Display Material and Technology, School of Electronics and Information Technology, Sun Yat-sen University, Guangzhou, China.
| | - Francesca Santoro
- Center for Advanced Biomaterials for Healthcare, Istituto Italiano di Tecnologia, Naples, Italy.
| | - Wenting Zhao
- School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore, Singapore.
| | - Nicolas H Voelcker
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia.
- Melbourne Centre for Nanofabrication, Victorian Node of the Australian National Fabrication Facility, Clayton, Victoria, Australia.
- CSIRO Manufacturing, Clayton, Victoria, Australia.
- Department of Materials Science and Engineering, Monash University, Clayton, Victoria, Australia.
| | - Roey Elnathan
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia.
- Melbourne Centre for Nanofabrication, Victorian Node of the Australian National Fabrication Facility, Clayton, Victoria, Australia.
- Department of Materials Science and Engineering, Monash University, Clayton, Victoria, Australia.
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6
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Survival of polymeric microstructures subjected to interrogatory touch. PLoS One 2021; 16:e0255980. [PMID: 34473714 PMCID: PMC8412302 DOI: 10.1371/journal.pone.0255980] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Accepted: 07/27/2021] [Indexed: 11/19/2022] Open
Abstract
Polymeric arrays of microrelief structures have a range of potential applications. For example, to influence wettability, to act as biologically inspired adhesives, to resist biofouling, and to play a role in the “feel” of an object during tactile interaction. Here, we investigate the damage to micropillar arrays comprising pillars of different modulus, spacing, diameter, and aspect ratio due to the sliding of a silicone cast of a human finger. The goal is to determine the effect of these parameters on the types of damage observed, including adhesive failure and ploughing of material from the finger onto the array. Our experiments point to four principal conclusions [1]. Aspect ratio is the dominant parameter in determining survivability through its effect on the bending stiffness of micropillars [2]. All else equal, micropillars with larger diameter are less susceptible to breakage and collapse [3]. The spacing of pillars in the array largely determines which type of adhesive failure occurs in non-surviving arrays [4]. Elastic modulus plays an important role in survivability. Clear evidence of elastic recovery was seen in the more flexible polymer and this recovery led to more instances of pristine survivability where the stiffer polymer tended to ablate PDMS. We developed a simple model to describe the observed bending of micropillars, based on the quasi-static mechanics of beam-columns, that indicated they experience forces ranging from 10−4–10−7 N to deflect into adhesive contact. Taken together, results obtained using our framework should inform design considerations for microstructures intended to be handled by human users.
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Lu P, Wang L, Zhu P, Huang J, Wang Y, Bai N, Wang Y, Li G, Yang J, Xie K, Zhang J, Yu B, Dai Y, Guo CF. Iontronic pressure sensor with high sensitivity and linear response over a wide pressure range based on soft micropillared electrodes. Sci Bull (Beijing) 2021; 66:1091-1100. [PMID: 36654343 DOI: 10.1016/j.scib.2021.02.019] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 01/14/2021] [Accepted: 01/29/2021] [Indexed: 01/20/2023]
Abstract
Electronic skins and flexible pressure sensors are important devices for advanced healthcare and intelligent robotics. Sensitivity is a key parameter of flexible pressure sensors. Whereas introducing surface microstructures in a capacitive-type sensor can significantly improve its sensitivity, the signal becomes nonlinear and the pressure response range gets much narrower, significantly limiting the applications of flexible pressure sensors. Here, we designed a pressure sensor that utilizes a nanoscale iontronic interface of an ionic gel layer and a micropillared electrode, for highly linear capacitance-to-pressure response and high sensitivity over a wide pressure range. The micropillars undergo three stages of deformation upon loading: initial contact (0-6 kPa) and structure buckling (6-12 kPa) that exhibit a low and nonlinear response, as well as a post-buckling stage that has a high signal linearity with high sensitivity (33.16 kPa-1) over a broad pressure range of 12-176 kPa. The high linearity lies in the subtle balance between the structure compression and mechanical matching of the two materials at the gel-electrode interface. Our sensor has been applied in pulse detection, plantar pressure mapping, and grasp task of an artificial limb. This work provides a physical insight in achieving linear response through the design of appropriate microstructures and selection of materials with suitable modulus in flexible pressure sensors, which are potentially useful in intelligent robots and health monitoring.
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Affiliation(s)
- Peng Lu
- Department of Materials Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
| | - Liu Wang
- Department of Materials Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
| | - Pang Zhu
- Department of Materials Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
| | - Jun Huang
- Department of Materials Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
| | - Yueji Wang
- Department of Materials Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
| | - Ningning Bai
- Department of Materials Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
| | - Yan Wang
- Department of Materials Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
| | - Gang Li
- Department of Materials Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
| | - Junlong Yang
- Department of Materials Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
| | - Kewei Xie
- Department of Materials Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
| | - Jianming Zhang
- Academy for Advanced Interdisciplinary Studies, Southern University of Science and Technology, Shenzhen 518055, China
| | - Bo Yu
- Ningbo Fengcheng Advanced Energy Materials Research Institute, Ningbo 315500, China
| | - Yuan Dai
- Tencent Robotics X, Shenzhen 518000, China
| | - Chuan Fei Guo
- Department of Materials Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China; Centers for Mechanical Engineering Research and Education at MIT and SUSTech & Shenzhen Engineering Research Center for Novel Electronic Information Materials and Devices, Southern University of Science and Technology, Shenzhen 518055, China.
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8
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Luo Z, Zhang XA, Chang CH. Magnetically responsive polymer nanopillars with nickel cap. NANOTECHNOLOGY 2021; 32:205301. [PMID: 33567417 DOI: 10.1088/1361-6528/abe4fc] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Embedding magnetic particles within polymer matrix is a common and facile method to fabricate magnetically responsive micro-/nanoscale pillars. However, the balance between mechanical compliance and magnetic susceptibility cannot be decoupled and the particles are limited by the pillar feature size, which can limit the actuation performance. Here we demonstrate a new type of magnetically responsive nanostructure consisting of a polydimethylsiloxane (PDMS) nanopillar array with deposited nickel caps, that has successfully achieved such decoupling with multiple cap-geometry designs for a better actuation control. The actuation result of nanopillars with 540 nm period and 1.3 μm height has been analyzed using image processing, leading to a maximum displacement of 180 nm with a ratio of 13.9% with respect to the pillar height. Magnetic and mechanical models based on magnetic force and torque have been developed and used to mitigate the weakening effect of the actuation by the residual magnetic layer. This structure demonstrates a feasible strategy for magnetic actuation at the sub-micrometer scale with freedom to design magnetic cap and polymeric pillar separately. This structure can also be utilized in multiple applications such as tunable optical elements, dynamic droplet manipulation, and responsive particle manipulation.
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Affiliation(s)
- Zhiren Luo
- Walker Department of Mechanical Engineering, University of Texas at Austin, Austin, TX 78712, United States of America
| | - Xu A Zhang
- Department of Mechanical and Aerospace Engineering, North Carolina State University, Raleigh, NC 27695, United States of America
| | - Chih-Hao Chang
- Walker Department of Mechanical Engineering, University of Texas at Austin, Austin, TX 78712, United States of America
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9
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Scott SM, Ali Z. Fabrication Methods for Microfluidic Devices: An Overview. MICROMACHINES 2021; 12:319. [PMID: 33803689 PMCID: PMC8002879 DOI: 10.3390/mi12030319] [Citation(s) in RCA: 128] [Impact Index Per Article: 42.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Revised: 03/12/2021] [Accepted: 03/13/2021] [Indexed: 12/20/2022]
Abstract
Microfluidic devices offer the potential to automate a wide variety of chemical and biological operations that are applicable for diagnostic and therapeutic operations with higher efficiency as well as higher repeatability and reproducibility. Polymer based microfluidic devices offer particular advantages including those of cost and biocompatibility. Here, we describe direct and replication approaches for manufacturing of polymer microfluidic devices. Replications approaches require fabrication of mould or master and we describe different methods of mould manufacture, including mechanical (micro-cutting; ultrasonic machining), energy-assisted methods (electrodischarge machining, micro-electrochemical machining, laser ablation, electron beam machining, focused ion beam (FIB) machining), traditional micro-electromechanical systems (MEMS) processes, as well as mould fabrication approaches for curved surfaces. The approaches for microfluidic device fabrications are described in terms of low volume production (casting, lamination, laser ablation, 3D printing) and high-volume production (hot embossing, injection moulding, and film or sheet operations).
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Affiliation(s)
| | - Zulfiqur Ali
- Healthcare Innovation Centre, School of Health and Life Sciences, Teesside University, Middlesbrough, Tees Valley TS1 3BX, UK
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10
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Ko J, Berger R, Lee H, Yoon H, Cho J, Char K. Electronic effects of nano-confinement in functional organic and inorganic materials for optoelectronics. Chem Soc Rev 2021; 50:3585-3628. [DOI: 10.1039/d0cs01501f] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
This review provides a comprehensive overview of the electronic effects of nano-confinement (from 1D to 3D geometries) on optoelectronic materials and their applications.
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Affiliation(s)
- Jongkuk Ko
- Department of Chemical and Biological Engineering
- Korea University
- Seoul 02841
- Republic of Korea
- School of Chemical & Biological Engineering
| | - Rüdiger Berger
- Physics at Interfaces
- Max Planck Institute for Polymer Research
- D-55128 Mainz
- Germany
| | - Hyemin Lee
- Department of Chemical & Biomolecular Engineering
- Seoul National University of Science & Technology
- Seoul 01811
- Republic of Korea
| | - Hyunsik Yoon
- Department of Chemical & Biomolecular Engineering
- Seoul National University of Science & Technology
- Seoul 01811
- Republic of Korea
| | - Jinhan Cho
- Department of Chemical and Biological Engineering
- Korea University
- Seoul 02841
- Republic of Korea
- KU-KIST Graduate School of Converging Science and Technology
| | - Kookheon Char
- School of Chemical & Biological Engineering
- Seoul National University
- Seoul 08826
- Republic of Korea
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11
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Oh J, Hoffman JB, Hong S, Jo KD, Román-Kustas J, Reed JH, Dana CE, Cropek DM, Alleyne M, Miljkovic N. Dissolvable Template Nanoimprint Lithography: A Facile and Versatile Nanoscale Replication Technique. NANO LETTERS 2020; 20:6989-6997. [PMID: 32790414 DOI: 10.1021/acs.nanolett.0c01547] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Nanoimprinting lithography (NIL) is a next-generation nanofabrication method, capable of replicating nanostructures from original master surfaces. Here, we develop highly scalable, simple, and nondestructive NIL using a dissolvable template. Termed dissolvable template nanoimprinting lithography (DT-NIL), our method utilizes an economic thermoplastic resin to fabricate nanoimprinting templates, which can be easily dissolved in simple organic solvents. We used the DT-NIL method to replicate cicada wings which have surface nanofeatures of ∼100 nm in height. The master, template, and replica surfaces showed a >∼94% similarity based on the measured diameter and height of the nanofeatures. The versatility of DT-NIL was also demonstrated with the replication of re-entrant, multiscale, and hierarchical features on fly wings, as well as hard silicon wafer-based artificial nanostructures. The DT-NIL method can be performed under ambient conditions with inexpensive materials and equipment. Our work opens the door to opportunities for economical and high-throughput nanofabrication processes.
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Affiliation(s)
- Junho Oh
- Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
- Department of Mechanical Engineering, University College London, London, WC1E 7JE, United Kingdom
| | - Jacob B Hoffman
- Construction Engineering Research Laboratory, U.S. Army Engineer Research and Development Center, Champaign, Illinois 61822, United States
| | - Sungmin Hong
- Construction Engineering Research Laboratory, U.S. Army Engineer Research and Development Center, Champaign, Illinois 61822, United States
| | - Kyoo D Jo
- Construction Engineering Research Laboratory, U.S. Army Engineer Research and Development Center, Champaign, Illinois 61822, United States
| | - Jessica Román-Kustas
- Construction Engineering Research Laboratory, U.S. Army Engineer Research and Development Center, Champaign, Illinois 61822, United States
- Materials Reliability, Sandia National Laboratories, Albuquerque, New Mexico 87123, United States
| | - Julian H Reed
- Construction Engineering Research Laboratory, U.S. Army Engineer Research and Development Center, Champaign, Illinois 61822, United States
| | - Catherine E Dana
- Department of Entomology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Donald M Cropek
- Construction Engineering Research Laboratory, U.S. Army Engineer Research and Development Center, Champaign, Illinois 61822, United States
| | - Marianne Alleyne
- Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
- Department of Entomology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
- Beckman Institute of Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Nenad Miljkovic
- Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
- Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
- Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
- International Institute for Carbon Neutral Energy Research (WPI-I2CNER), Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka 819-0395, Japan
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12
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Chen L, Zhao C, Liu L, Xu L. Single mode operation and ultrawide tuning of on-chip optofluidic dye lasers. LAB ON A CHIP 2020; 20:3757-3762. [PMID: 32901652 DOI: 10.1039/d0lc00742k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Single transverse mode lasers that can be continuously tuned over ultrawide wavelength ranges with a narrow linewidth are very important components for lab-on-a-chip systems. Such lasers that can be tuned over the whole visible spectrum or even beyond have not been demonstrated hitherto regardless of many years of research in this area. This article presents an on-chip optofluidic distributed Bragg reflector (DBR) dye laser constituted by a combination of a T-shaped optofluidic waveguide (T waveguide) and two ridge-waveguide-based fluidic DBR gratings, in which the T waveguide provides gain for lasing and the DBR gratings select the lasing wavelength. This configuration guarantees that the fundamental mode has a much lower loss (consequently much lower lasing threshold) than all the higher order modes. By fabricating PDMS devices of such structure and changing the fluid in DBR gratings as well as the gain fluid in the T waveguide, we demonstrate a single mode optofluidic dye laser that can be continuously tuned over a wavelength range of more than 450 nm with a linewidth less than 0.1 nm. Mode patterns obtained when using different laser dyes in the T waveguide verify fundamental mode operation over the wide wavelength range.
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Affiliation(s)
- Lin Chen
- Key Lab for Micro and Nanophotonic Structures (Ministry of Education, China), Department of Optical Science and Engineering, School of Information Science and Engineering, Fudan University, Shanghai 200433, China.
| | - Chenming Zhao
- Key Lab for Micro and Nanophotonic Structures (Ministry of Education, China), Department of Optical Science and Engineering, School of Information Science and Engineering, Fudan University, Shanghai 200433, China.
| | - Liying Liu
- Key Lab for Micro and Nanophotonic Structures (Ministry of Education, China), Department of Optical Science and Engineering, School of Information Science and Engineering, Fudan University, Shanghai 200433, China.
| | - Lei Xu
- Key Lab for Micro and Nanophotonic Structures (Ministry of Education, China), Department of Optical Science and Engineering, School of Information Science and Engineering, Fudan University, Shanghai 200433, China. and Department of Physics, Fudan University, Shanghai 200433, China
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13
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Minin IV, Minin OV, Liu CY, Wei HD, Geints YE, Karabchevsky A. Experimental demonstration of a tunable photonic hook by a partially illuminated dielectric microcylinder. OPTICS LETTERS 2020; 45:4899-4902. [PMID: 32870885 DOI: 10.1364/ol.402248] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Accepted: 07/30/2020] [Indexed: 06/11/2023]
Abstract
In this Letter, we report the experimental observations of a tunable curved photonic nanojet (photonic hook) generated by a 5 µm polydimethylsiloxane microcylinder deposited on a silicon substrate and illuminated by 405 nm laser beam. A moveable opaque aluminum-mask is mounted in front of the microcylinder implementing partial illumination and imparting spatial curvature to the photonic nanojet. Experimental results of main parameters (tilt angle, width, and intensity) of emerging photonic hooks exhibit close agreement with numerical predictions of the near-field optical structures. The experimentally measured full widths at half-maximum of photonic hooks are 0.48λ, 0.56λ, and 0.76λ for tilt angles of θ=0∘, 5.7°, and 20.1°, respectively. Photonic hooks possess great potential in complex manipulation such as super-resolution imaging, surface fabrication, and optomechanical manipulation along curved trajectories.
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14
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Abstract
The study of accelerating Airy-family beams has made significant progress, not only in terms of numerical and experimental investigations, but also in conjunction with many potential applications. However, the curvature of such beams (and hence their acceleration) is usually greater than the wavelength. Relatively recently, a new type of localized wave beams with subwavelength curvature, called photonic hooks, was discovered. This paper briefly reviews the substantial literature concerning photonic jet and photonic hook phenomena, based on the photonic jet principle. Meanwhile, the photonic jet ensemble can be produced by optical wave diffraction at 2D phase diffraction gratings. The guidelines of jets’ efficient manipulation, through the variation of both the shape and spatial period of diffraction grating rulings, are considered. Amazingly, the mesoscale dielectric Janus particle, with broken shape or refractive index symmetry, is used to generate the curved photonic jet—a photonic hook—emerging from its shadow-side surface. Using the photonic hook, the resolution of optical scanning systems can be improved to develop optomechanical tweezers for moving nanoparticles, cells, bacteria and viruses along curved paths and around transparent obstacles. These unique properties of photonic jets and hooks combine to afford important applications for low-loss waveguiding, subdiffraction-resolution nanopatterning and nanolithography.
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15
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Minin IV, Liu CY, Yang YC, Staliunas K, Minin OV. Experimental observation of flat focusing mirror based on photonic jet effect. Sci Rep 2020; 10:8459. [PMID: 32439953 PMCID: PMC7242355 DOI: 10.1038/s41598-020-65292-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Accepted: 04/24/2020] [Indexed: 11/13/2022] Open
Abstract
In this work, we experimentally demonstrate that a thin rectangle dielectric-metal structure can have a function of a flat focusing mirror based on photonic jet effect in reflection mode. Using polydimethylsiloxane (PDMS) rectangle with size length of 10 μm and wavelength-scale thickness of 1 μm on the top of a silicon wafer, we have built a flat mirror which focuses an incident beam at the focal length changing from 1.38 μm to 11.67 μm upon tuning the beam incidence angle from 30° to 75°. The focusing properties of such a mirror persist in the wavelength range of 405 nm to 671 nm. Our approach can be extended to realize other optical functionalities by properly controlling rectangle dimensions and materials. This flat focusing mirror is able to guide the incident beam in free space without perceptible diffraction at the distance equal to the photonic jet length and suitable for small-scale photonic circuits.
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Affiliation(s)
- Igor V Minin
- Tomsk State Politechnical University, Tomsk, 36 Lenin Avenue, 634050, Russia.,Tomsk State University, Tomsk, 30 Lenin Avenue, 634050, Russia
| | - Cheng-Yang Liu
- Department of Biomedical Engineering, National Yang-Ming University, 11221, Taipei City, Taiwan.
| | - Yu-Chih Yang
- Department of Biomedical Engineering, National Yang-Ming University, 11221, Taipei City, Taiwan
| | - Kestutis Staliunas
- ICREA, Passeig Lluís Companys 23, 08010, Barcelona, Spain.,UPC, Dep. de Fisica, Rambla Sant Nebridi 22, 08222, Terrassa, Barcelona, Spain
| | - Oleg V Minin
- Tomsk State Politechnical University, Tomsk, 36 Lenin Avenue, 634050, Russia.,Tomsk State University, Tomsk, 30 Lenin Avenue, 634050, Russia
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16
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Luo Z, Zhang XA, Evans BA, Chang CH. Active Periodic Magnetic Nanostructures with High Aspect Ratio and Ultrahigh Pillar Density. ACS APPLIED MATERIALS & INTERFACES 2020; 12:11135-11143. [PMID: 32017524 DOI: 10.1021/acsami.9b18423] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Magnetically actuated micro/nanoscale pillars have attracted significant research interest recently because of their dynamic properties. These structures can be used for various applications, such as dry adhesion, cell manipulation, and sensors or actuators in microfluidics. Magnetically actuated structures can be fabricated by mixing magnetic particles and polymers to yield a favorable combination of magnetic permeability and mechanical compliance. However, the pillar density of demonstrated structures is relatively low, which limits the potential applications in active surface manipulation of microscale objects. Here, we demonstrate active periodic nanostructures with a pillar density of 0.25 pillar/μm2, which is the highest density for magnetically actuated pillars so far. Having a structure period of 2 μm, diameter of 600 nm, and high aspect ratio of up to 11, this structure can be magnetically actuated with a displacement of up to 200 nm. The behaviors of the pillars under various cyclic actuation modes have been characterized, demonstrating that the actuation can be well controlled. This work can find potential applications in particle manipulation and tunable photonic elements.
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Affiliation(s)
- Zhiren Luo
- Department of Mechanical and Aerospace Engineering, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Xu A Zhang
- Department of Mechanical and Aerospace Engineering, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Benjamin Aaron Evans
- Department of Physics, Elon University, Elon, North Carolina 27244, United States
| | - Chih-Hao Chang
- Department of Mechanical and Aerospace Engineering, North Carolina State University, Raleigh, North Carolina 27695, United States
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17
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Lee KS, Song Y, Kim CH, Kim YT, Kang T, Lee SJ, Choi BG, Lee KG. Development of zinc oxide-based sub-micro pillar arrays for on-site capture and DNA detection of foodborne pathogen. J Colloid Interface Sci 2020; 563:54-61. [DOI: 10.1016/j.jcis.2019.12.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Revised: 11/30/2019] [Accepted: 12/02/2019] [Indexed: 11/28/2022]
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18
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Nouri-Goushki M, Sharma A, Sasso L, Zhang S, Van der Eerden BCJ, Staufer U, Fratila-Apachitei LE, Zadpoor AA. Submicron Patterns-on-a-Chip: Fabrication of a Microfluidic Device Incorporating 3D Printed Surface Ornaments. ACS Biomater Sci Eng 2019; 5:6127-6136. [DOI: 10.1021/acsbiomaterials.9b01155] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Mahdiyeh Nouri-Goushki
- Department of Biomechanical Engineering, Faculty of Mechanical, Maritime, and Materials Engineering, Delft University of Technology (TU Delft), Mekelweg 2, 2628 CD Delft, The Netherlands
| | - Abhishek Sharma
- Department of Precision and Microsystems Engineering, Faculty of Mechanical, Maritime, and Materials Engineering, Delft University of Technology (TU Delft), Mekelweg 2, 2628 CD Delft, The Netherlands
| | - Luigi Sasso
- Department of Precision and Microsystems Engineering, Faculty of Mechanical, Maritime, and Materials Engineering, Delft University of Technology (TU Delft), Mekelweg 2, 2628 CD Delft, The Netherlands
| | - Shuang Zhang
- Department of Internal Medicine, Erasmus Medical Center, Dr. Molewaterplein 40, 3015 GD Rotterdam, The Netherlands
| | - Bram C. J. Van der Eerden
- Department of Internal Medicine, Erasmus Medical Center, Dr. Molewaterplein 40, 3015 GD Rotterdam, The Netherlands
| | - Urs Staufer
- Department of Precision and Microsystems Engineering, Faculty of Mechanical, Maritime, and Materials Engineering, Delft University of Technology (TU Delft), Mekelweg 2, 2628 CD Delft, The Netherlands
| | - Lidy E. Fratila-Apachitei
- Department of Biomechanical Engineering, Faculty of Mechanical, Maritime, and Materials Engineering, Delft University of Technology (TU Delft), Mekelweg 2, 2628 CD Delft, The Netherlands
| | - Amir A. Zadpoor
- Department of Biomechanical Engineering, Faculty of Mechanical, Maritime, and Materials Engineering, Delft University of Technology (TU Delft), Mekelweg 2, 2628 CD Delft, The Netherlands
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19
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Parameswaran C, Gupta D. Large area flexible pressure/strain sensors and arrays using nanomaterials and printing techniques. NANO CONVERGENCE 2019; 6:28. [PMID: 31495907 PMCID: PMC6732266 DOI: 10.1186/s40580-019-0198-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Accepted: 07/17/2019] [Indexed: 05/04/2023]
Abstract
Sensors are becoming more demanding in all spheres of human activities for their advancement in terms of fabrication and cost. Several methods of fabrication and configurations exist which provide them myriad of applications. However, the advantage of fabrication for sensors lies with bulk fabrication and processing techniques. Exhaustive study for process advancement towards miniaturization from the advent of MEMS technology has been going on and progressing at high pace and has reached a highly advanced level wherein batch production and low cost alternatives provide a competitive performance. A look back to this advancement and thus understanding the route further is essential which is the core of this review in light of nanomaterials and printed technology based sensors. A subjective appraisal of these developments in sensor architecture from the advent of MEMS technology converging present date novel materials and process technologies through this article help us understand the path further.
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Affiliation(s)
- Chithra Parameswaran
- Plastic Electronics and Energy Laboratory, Department of Metallurgical Engineering and Materials Science, Indian Institute of Technology Bombay, Mumbai, 400076 India
| | - Dipti Gupta
- Plastic Electronics and Energy Laboratory, Department of Metallurgical Engineering and Materials Science, Indian Institute of Technology Bombay, Mumbai, 400076 India
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20
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Development of Open-Tubular-Type Micro Gas Chromatography Column with Bump Structures. SENSORS 2019; 19:s19173706. [PMID: 31455012 PMCID: PMC6749250 DOI: 10.3390/s19173706] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 08/14/2019] [Accepted: 08/23/2019] [Indexed: 12/18/2022]
Abstract
Gas chromatography (GC) is the chemical analysis technique most widely used to separate and identify gas components, and it has been extensively applied in various gas analysis fields such as non-invasive medical diagnoses, indoor air quality monitoring, and outdoor environmental monitoring. Micro-electro-mechanical systems (MEMS)-based GC columns are essential for miniaturizing an integrated gas analysis system (Micro GC system). This study reports an open-tubular-type micro GC (μ-GC) column with internal bump structures (bump structure μ-GC column) that substantially increase the interaction between the gas mixture and a stationary phase. The developed bump structure μ-GC column, which was fabricated on a 2 cm × 2 cm μ-GC chip and coated with a non-polar stationary phase, is 1.5 m-long, 150 μm-wide, and 400 μm-deep. It has an internal microfluidic channel in which the bumps, which are 150 μm diameter half-circles, are alternatingly disposed to face each other on the surface of the microchannel. The fabricated bump structure μ-GC column yielded a height-equivalent-to-a-theoretical-plate (HETP) of 0.009 cm (11,110 plates/m) at an optimal carrier gas velocity of 17 cm/s. The mechanically robust bump structure μ-GC column proposed in this study achieved higher separation efficiency than a commercially available GC column and a typical μ-GC column with internal post structures classified as a semi-packed-type column. The experimental results demonstrate that the developed bump structure μ-GC column can separate a gas mixture completely, with excellent separation resolution for formaldehyde, benzene, toluene, ethylbenzene, and xylene mixture, under programmed operating temperatures.
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21
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Liu CY, Yeh MJ. Experimental verification of twin photonic nanojets from a dielectric microcylinder. OPTICS LETTERS 2019; 44:3262-3265. [PMID: 31259936 DOI: 10.1364/ol.44.003262] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2019] [Accepted: 06/03/2019] [Indexed: 06/09/2023]
Abstract
In this Letter, the direct generation of twin photonic nanojets (PNJs) through two coherent illuminations of a microcylinder is investigated theoretically and experimentally. The dielectric microcylinder (polydimethylsiloxane) with 5 μm diameter and 6 μm height is employed to generate symmetric twin PNJs. The finite-difference time-domain calculation is used to simulate the electric field distributions inside and outside the microcylinder. The scanning optical microscope system is performed for experimental verification of twin photonic nanojets. In both theory and in practice, the intensity null of electric field creates two separate PNJs. Compared to a single PNJ, twin PNJs have a smaller subwavelength waist and more complex intensity distribution. The focal distance, interval, and full width at half-maximum of twin PNJs are a function of the offset angle. The twin PNJs will provide novel applications in nanolithography, optical trapping, biophotonic sensing, and therapy.
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22
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Surface topographies of biomimetic superamphiphobic materials: design criteria, fabrication and performance. Adv Colloid Interface Sci 2019; 269:87-121. [PMID: 31059923 DOI: 10.1016/j.cis.2019.04.007] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2019] [Revised: 03/15/2019] [Accepted: 04/24/2019] [Indexed: 12/26/2022]
Abstract
Superamphiphobicity is a wetting phenomenon that not only water but also oils or organic solvents with low surface tension exhibit large contact angles above 150° along with low contact angle hysteresis on solid surface. It is well known that both chemical constituent and surface roughness have impacts on the wettability of solid surface. Herein, several fundamental wetting states and design criteria for re-entrant structures are introduced first. Then, various chemical modification materials endowing solid substrates low surface energy are summarized subsequently. Furthermore, roughening processes conferring hierarchical or re-entrant topographic structures on surfaces are classified based on different types of topographies abstracted from the natural oil-repellent creatures (mushroom-like structures) as well as bio-inspired superamphiphobic surfaces (i.e., randomly distributed nanostructures, regularly patterned microstructures and other complex hierarchical structures). Significantly, the impalement pressure and formulated rules of various re-entrant profiles are recommended in detail. At the same time, fabrication, outstanding performances such as mechanical durability, chemical stability are also mentioned according to different types of morphologies. Beyond that, current fabrication obstacles and future prospects are proposed simultaneously in the end.
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23
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Characterization and Neutral Atom Beam Surface Modification of a Clear Castable Polyurethane for Biomicrofluidic Applications. SURFACES 2019. [DOI: 10.3390/surfaces2010009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Polyurethanes (PU) are a broad class of polymers that offer good solvent compatibility and a wide range of properties that can be used to generate microfluidic layers. Here, we report the first characterization of a commercially available Shore 80D polyurethane (Ultraclear™ 480N) for biomicrofluidic applications. Studies included comparing optical clarity with Polydimethylsiloxane (PDMS) and using high-fidelity replica molding to produce solid PU structures from the millimeter to nanometer scales. Additionally, we report the first use of NanoAccel™ treatment in Accelerated Neutral Atom Beam (ANAB) mode to permanently roughen the surface of PU and improve the adhesion of breast cancer cells (MDA-MB-231) on PU. Surface energy measurements using Owens-Wendt equations indicate an increase in polar and total surface energy due to ANAB treatment. Fourier-transform infrared (FTIR) spectroscopy in attenuated total reflectance (ATR) mode was used to demonstrate that the treatment does not introduce any new types of functional groups on the surface of Ultraclear™ PU. Finally, applicability in rapid prototyping for biomicrofluidics was demonstrated by utilizing a 3D-printing-based replica molding strategy to create PU microfluidic layers. These layers were sealed to polystyrene (PS) bases to produce PU-PS microfluidic chips. Ultraclear™ PU can serve as a clear and castable alternative to PDMS in biomicrofluidic studies.
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24
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Sen AK, Raj A, Banerjee U, Iqbal SR. Soft Lithography, Molding, and Micromachining Techniques for Polymer Micro Devices. Methods Mol Biol 2019; 1906:13-54. [PMID: 30488383 DOI: 10.1007/978-1-4939-8964-5_2] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
This chapter enumerates the methods, protocol, and safety procedures of various fabrication techniques for polymer-based microfluidic devices. The polymer materials can be a solid or a liquid, and the fabrication protocol needs to be executed accordingly. Various techniques demonstrating the fabrication of microfluidic devices using solid and liquid polymers are described. Procedure for each fabrication process is delineated with detailed images. Further, dos and don'ts for all the fabrication techniques are explained in the notes of each section. This chapter will benefit those interested in the microfluidic device fabrication using polymers and guide them to avoid mistakes so as to obtain an elegant device.The techniques are listed as follows: 1. Replica molding 2. Microcontact printing 3. Micro-transfer molding 4. Solvent-assisted molding 5. Hot embossing 6. Injection molding 7. CNC micromachining 8. Laser photo ablation 9. X-ray lithography 10. UV patterning 11. Plasma etching 12. Ion beam etching 13. Capillary molding 14. Micro-stereolithography.
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Affiliation(s)
- Ashis Kumar Sen
- Department of Mechanical Engineering, Indian Institute of Technology Madras, Chennai, India.
| | - Abhishek Raj
- Department of Mechanical Engineering, Indian Institute of Technology Madras, Chennai, India
| | - Utsab Banerjee
- Department of Mechanical Engineering, Indian Institute of Technology Madras, Chennai, India
| | - Sk Rameez Iqbal
- Department of Mechanical Engineering, Indian Institute of Technology Madras, Chennai, India
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25
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Top-down fabrication of shape-controlled, monodisperse nanoparticles for biomedical applications. Adv Drug Deliv Rev 2018; 132:169-187. [PMID: 30009884 DOI: 10.1016/j.addr.2018.07.006] [Citation(s) in RCA: 81] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Revised: 06/08/2018] [Accepted: 07/06/2018] [Indexed: 01/01/2023]
Abstract
Nanoparticles for biomedical applications are generally formed by bottom-up approaches such as self-assembly, emulsification and precipitation. But these methods usually have critical limitations in fabrication of nanoparticles with controllable morphologies and monodispersed size. Compared with bottom-up methods, top-down nanofabrication techniques offer advantages of high fidelity and high controllability. This review focuses on top-down nanofabrication techniques for engineering particles along with their biomedical applications. We present several commonly used top-down nanofabrication techniques that have the potential to fabricate nanoparticles, including photolithography, interference lithography, electron beam lithography, mold-based lithography (nanoimprint lithography and soft lithography), nanostencil lithography, and nanosphere lithography. Varieties of current and emerging applications are also covered: (i) targeting, (ii) drug and gene delivery, (iii) imaging, and (iv) therapy. Finally, a future perspective of the nanoparticles fabricated by the top-down techniques in biomedicine is also addressed.
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26
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Goswami D, Munera JC, Pal A, Sadri B, Scarpetti CLPG, Martinez RV. Roll-to-Roll Nanoforming of Metals Using Laser-Induced Superplasticity. NANO LETTERS 2018; 18:3616-3622. [PMID: 29775318 DOI: 10.1021/acs.nanolett.8b00714] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
This Letter describes a low-cost, scalable nanomanufacturing process that enables the continuous forming of thin metallic layers with nanoscale accuracy using roll-to-roll, laser-induced superplasticity (R2RLIS). R2RLIS uses a laser shock to induce the ultrahigh-strain-rate deformation of metallic films at room temperature into low-cost polymeric nanomolds, independently of the original grain size of the metal. This simple and inexpensive nanoforming method does not require access to cleanrooms and associated facilities, and can be easily implemented on conventional CO2 lasers, enabling laser systems commonly used for rapid prototyping or industrial cutting and engraving to fabricate uniform and three-dimensional crystalline metallic nanostructures over large areas. Tuning the laser power during the R2RLIS process enables the control of the aspect ratio and the mechanical and optical properties of the fabricated nanostructures. This roll-to-roll technique successfully fabricates mechanically strengthened gold plasmonic nanostructures with aspect ratios as high as 5 that exhibit high oxidation resistance and strong optical field enhancements. The CO2 laser used in R2RLIS can also integrate the fabricated nanostructures on transparent flexible substrates with robust interfacial contact. The ability to fabricate ultrasmooth metallic nanostructures using roll-to-roll manufacturing enables the large scale production, at a relatively low-cost, of flexible plasmonic devices toward emerging applications.
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Affiliation(s)
- Debkalpa Goswami
- School of Industrial Engineering , Purdue University , 315 N. Grant Street , West Lafayette , Indiana 47907 , United States
| | - Juan C Munera
- School of Industrial Engineering , Purdue University , 315 N. Grant Street , West Lafayette , Indiana 47907 , United States
| | - Aniket Pal
- School of Industrial Engineering , Purdue University , 315 N. Grant Street , West Lafayette , Indiana 47907 , United States
| | - Behnam Sadri
- School of Industrial Engineering , Purdue University , 315 N. Grant Street , West Lafayette , Indiana 47907 , United States
| | - Caio Lui P G Scarpetti
- School of Industrial Engineering , Purdue University , 315 N. Grant Street , West Lafayette , Indiana 47907 , United States
| | - Ramses V Martinez
- School of Industrial Engineering , Purdue University , 315 N. Grant Street , West Lafayette , Indiana 47907 , United States
- Weldon School of Biomedical Engineering , Purdue University 206 S. Martin Jischke Drive , West Lafayette , Indiana 47907 , United States
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Thickness-independent capacitance of vertically aligned liquid-crystalline MXenes. Nature 2018; 557:409-412. [DOI: 10.1038/s41586-018-0109-z] [Citation(s) in RCA: 688] [Impact Index Per Article: 114.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Accepted: 03/05/2018] [Indexed: 11/08/2022]
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28
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Ultra-fast responsive colloidal-polymer composite-based volatile organic compounds (VOC) sensor using nanoscale easy tear process. Sci Rep 2018; 8:5291. [PMID: 29593354 PMCID: PMC5871848 DOI: 10.1038/s41598-018-23616-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Accepted: 03/16/2018] [Indexed: 12/02/2022] Open
Abstract
There is an immense need for developing a simple, rapid, and inexpensive detection assay for health-care applications or monitoring environments. To address this need, a photonic crystal (PC)-based sensor has been extensively studied due to its numerous advantages such as colorimetric measurement, high sensitivity, and low cost. However, the response time of a typical PC-based sensor is relatively slow due to the presence of the inevitable upper residual layer in colloidal structures. Hence, we propose an ultra-fast responsive PC-based volatile organic compound (VOC) sensor by using a “nanoscale easy tear (NET) process” inspired by commercially available “easy tear package”. A colloidal crystal-polydimethylsiloxane (PDMS) composite can be successfully realized through nanoscale tear propagation along the interface between the outer surface of crystallized nanoparticles and bulk PDMS. The response time for VOC detection exhibits a significant decrease by allowing the direct contact with VOCs, because of perfect removal of the residual on the colloidal crystals. Moreover, vapor-phase VOCs can be monitored, which had been previously impossible. High-throughput production of the patterned colloidal crystal–polymer composite through the NET process can be applied to other multiplexed selective sensing applications or may be used for nanomolding templates.
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Patil S, Deshpande T, Chaudhari N, Singh YRG, Raut J, Joshi YM, Sharma A. Making Nonsticky Surfaces of Sticky Materials: Self-Organized Microtexturing of Viscoelastic Elastomeric Layers by Tearing. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:3767-3774. [PMID: 29505263 DOI: 10.1021/acs.langmuir.7b04389] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Fabrication of large area, multiscale microtextured surfaces engineered for antiadhesion properties remains a challenge. Compared to an elastic surface, viscoelastic solids show much higher surface stickiness, tack, and adhesion owing to the increased contact area and energy dissipation. Here, we show a simple, low cost, large-area and high throughput method with roll-to-roll compatibility to fabricate multiscale, rough microstructures resistant to adhesion in a viscoelastic layer by controlled tearing of viscous film. Even a high adhesive strength viscoelastic solid layer, such as partially cured PDMS, is made nonsticky simply by its controlled tearing. The torn surface shows a fracture induced, self-organized leaflike micropattern resistant to sticking. The topography and adhesion strength of these structures are readily tuned by changing the tearing speed and the film thickness. The microtexture displays a springlike recovery, low adhesive strength, and easy release properties even under the high applied loads.
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Affiliation(s)
- Sandip Patil
- Department of Chemical Engineering , Indian Institute of Technology , Kanpur - 208016 , U.P. , India
| | - Tushar Deshpande
- Department of Chemical Engineering , Indian Institute of Technology , Kanpur - 208016 , U.P. , India
| | - Nayantika Chaudhari
- Department of Chemical Engineering , Indian Institute of Technology , Kanpur - 208016 , U.P. , India
| | - Yogesh R G Singh
- Department of Chemical Engineering , Indian Institute of Technology , Kanpur - 208016 , U.P. , India
| | - Janhavi Raut
- Unilever R&D , 64 Main Road, Whitefield , Bangalore 560066 , India
| | - Yogesh M Joshi
- Department of Chemical Engineering , Indian Institute of Technology , Kanpur - 208016 , U.P. , India
| | - Ashutosh Sharma
- Department of Chemical Engineering , Indian Institute of Technology , Kanpur - 208016 , U.P. , India
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30
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Li Q, Peer A, Cho IH, Biswas R, Kim J. Replica molding-based nanopatterning of tribocharge on elastomer with application to electrohydrodynamic nanolithography. Nat Commun 2018; 9:974. [PMID: 29500374 PMCID: PMC5834498 DOI: 10.1038/s41467-018-03319-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Accepted: 02/05/2018] [Indexed: 11/22/2022] Open
Abstract
Replica molding often induces tribocharge on elastomers. To date, this phenomenon has been studied only on untextured elastomer surfaces even though replica molding is an effective method for their nanotexturing. Here we show that on elastomer surfaces nanotextured through replica molding the induced tribocharge also becomes patterned at nanoscale in close correlation with the nanotexture. By applying Kelvin probe microscopy, electrohydrodynamic lithography, and electrostatic analysis to our model nanostructure, poly(dimethylsiloxane) nanocup arrays replicated from a polycarbonate nanocone array, we reveal that the induced tribocharge is highly localized within the nanocup, especially around its rim. Through finite element analysis, we also find that the rim sustains the strongest friction during the demolding process. From these findings, we identify the demolding-induced friction as the main factor governing the tribocharge's nanoscale distribution pattern. By incorporating the resulting annular tribocharge into electrohydrodynamic lithography, we also accomplish facile realization of nanovolcanos with 10 nm-scale craters.
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Affiliation(s)
- Qiang Li
- Department of Electrical and Computer Engineering, Iowa State University, Ames, Iowa, 50011, USA
| | - Akshit Peer
- Department of Electrical and Computer Engineering, Iowa State University, Ames, Iowa, 50011, USA
- Ames Laboratory, Iowa State University, Ames, Iowa, 50011, USA
- Microelectronics Research Center, Iowa State University, Ames, Iowa, 50011, USA
| | - In Ho Cho
- Department of Civil, Construction and Environmental Engineering, Iowa State University, Ames, Iowa, 50011, USA
| | - Rana Biswas
- Department of Electrical and Computer Engineering, Iowa State University, Ames, Iowa, 50011, USA.
- Ames Laboratory, Iowa State University, Ames, Iowa, 50011, USA.
- Microelectronics Research Center, Iowa State University, Ames, Iowa, 50011, USA.
- Department of Physics and Astronomy, Iowa State University, Ames, Iowa, 50011, USA.
| | - Jaeyoun Kim
- Department of Electrical and Computer Engineering, Iowa State University, Ames, Iowa, 50011, USA.
- Ames Laboratory, Iowa State University, Ames, Iowa, 50011, USA.
- Microelectronics Research Center, Iowa State University, Ames, Iowa, 50011, USA.
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31
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Li W, Zhou Y, Howell IR, Gai Y, Naik AR, Li S, Carter KR, Watkins JJ. Direct Imprinting of Scalable, High-Performance Woodpile Electrodes for Three-Dimensional Lithium-Ion Nanobatteries. ACS APPLIED MATERIALS & INTERFACES 2018; 10:5447-5454. [PMID: 29369613 DOI: 10.1021/acsami.7b14649] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The trend of device downscaling drives a corresponding need for power source miniaturization. Though numerous microfabrication methods lead to successful creation of submillimeter-scale electrodes, scalable approaches that provide cost-effective nanoscale resolution for energy storage devices such as on-chip batteries remain elusive. Here, we report nanoimprint lithography (NIL) as a direct patterning technique to fabricate high-performance TiO2 nanoelectrode arrays for lithium-ion batteries (LIBs) over relatively large areas. The critical electrode dimension is below 200 nm, which enables the structure to possess favorable rate capability even under discharging current densities as high as 5000 mA g-1. In addition, by sequential imprinting, electrodes with three-dimensional (3D) woodpile architecture were readily made in a "stack-up" manner. The height of architecture can be easily controlled by the number of stacked layers while maintaining nearly constant surface-to-volume ratios. The result is a proportional increase of areal capacity with the number of layers. The structure-processing combination leads to efficient use of the material, and the resultant specific capacity (250.9 mAh g-1) is among the highest reported. This work provides a simple yet effective strategy to fabricate nanobatteries and can be potentially extended to other electroactive materials.
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Affiliation(s)
- Wenhao Li
- Department of Polymer Science and Engineering, University of Massachusetts Amherst , Amherst, Massachusetts 01003, United States
| | - Yiliang Zhou
- Department of Polymer Science and Engineering, University of Massachusetts Amherst , Amherst, Massachusetts 01003, United States
| | - Irene R Howell
- Department of Polymer Science and Engineering, University of Massachusetts Amherst , Amherst, Massachusetts 01003, United States
| | - Yue Gai
- Department of Polymer Science and Engineering, University of Massachusetts Amherst , Amherst, Massachusetts 01003, United States
| | - Aditi R Naik
- Department of Polymer Science and Engineering, University of Massachusetts Amherst , Amherst, Massachusetts 01003, United States
| | - Shengkai Li
- Department of Polymer Science and Engineering, University of Massachusetts Amherst , Amherst, Massachusetts 01003, United States
| | - Kenneth R Carter
- Department of Polymer Science and Engineering, University of Massachusetts Amherst , Amherst, Massachusetts 01003, United States
| | - James J Watkins
- Department of Polymer Science and Engineering, University of Massachusetts Amherst , Amherst, Massachusetts 01003, United States
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32
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Zhang X, Han F, Syed A, Bukhari EM, Siang BCJ, Yang S, Zhou B, Wen WJ, Jiang D. Fabrication of highly modulable fibrous 3D extracellular microenvironments. Biomed Microdevices 2018; 19:53. [PMID: 28608128 DOI: 10.1007/s10544-017-0187-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Three-dimensional (3D) in vitro scaffolds that mimic the irregular fibrous structures of in vivo extracellular matrix (ECM) are critical for many important biological applications. However, structural properties modulation of fibrous 3D scaffolds remains a challenge. Here, we report the first highly modulable 3D fibrous scaffolds self-assembled by high-aspect-ratio (HAR) microfibers. The scaffolds structural properties can be easily tailored to incorporate various physical cues, including geometry, stiffness, heterogeneity and nanotopography. Moreover, the fibrous scaffolds are readily and accurately patterned on desired locations of the substrate. Cell culture exhibits that our scaffolds can elicit strong bidirectional cell-material interactions. Furthermore, a functional disparity between the two-dimensional substrate and our 3D scaffolds is identified by cell spreading and proliferation data. These results prove the potential of the proposed scaffold as a biomimetic extracellular microenvironment for cell study.
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Affiliation(s)
- Xixiang Zhang
- Physical Sciences and Engineering Division (PSE), King Abdullah University of Science and Technology, Thuwal, 23955-6900, Kingdom of Saudi Arabia.
| | - Fangfei Han
- State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, Jiangsu, 210093, People's Republic of China
| | - Ahad Syed
- Imaging & Characterization Core Lab, King Abdullah University of Science and Technology, Thuwal, 23955-6900, Kingdom of Saudi Arabia
| | - Ebtihaj M Bukhari
- Advanced Nanofabrication Core Lab, King Abdullah University of Science and Technology, Thuwal, 23955-6900, Kingdom of Saudi Arabia
| | - Basil Chew Joo Siang
- Imaging & Characterization Core Lab, King Abdullah University of Science and Technology, Thuwal, 23955-6900, Kingdom of Saudi Arabia
| | - Shan Yang
- Physical Sciences and Engineering Division (PSE), King Abdullah University of Science and Technology, Thuwal, 23955-6900, Kingdom of Saudi Arabia
| | - Bingpu Zhou
- Department of Physics, Hong Kong University of Science and Technology, Kowloon, Hong Kong, People's Republic of China
| | - Wei-Jia Wen
- Department of Physics, Hong Kong University of Science and Technology, Kowloon, Hong Kong, People's Republic of China
| | - Dechen Jiang
- State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, Jiangsu, 210093, People's Republic of China.
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33
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Rana A, Zhang Y, Esfandiari L. Advancements in microfluidic technologies for isolation and early detection of circulating cancer-related biomarkers. Analyst 2018; 143:2971-2991. [DOI: 10.1039/c7an01965c] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Isolation of circulating biomarkers using microfluidic devices for cancer diagnosis.
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Affiliation(s)
- Ankit Rana
- Department of Electrical Engineering and Computer Science
- College of Engineering and Applied Sciences
- University of Cincinnati
- Cincinnati
- USA
| | - Yuqian Zhang
- Department of Electrical Engineering and Computer Science
- College of Engineering and Applied Sciences
- University of Cincinnati
- Cincinnati
- USA
| | - Leyla Esfandiari
- Department of Electrical Engineering and Computer Science
- College of Engineering and Applied Sciences
- University of Cincinnati
- Cincinnati
- USA
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34
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Li Q, Dhakal R, Kim J. Microdroplet-based On-Demand Drawing of High Aspect-Ratio Elastomeric Micropillar and Its Contact Sensing Application. Sci Rep 2017; 7:17009. [PMID: 29209022 PMCID: PMC5717269 DOI: 10.1038/s41598-017-17230-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Accepted: 11/16/2017] [Indexed: 11/10/2022] Open
Abstract
High aspect-ratio elastomeric micropillars play important roles as the platform for microscale sensing and actuation. Many soft-lithographic techniques have been developed for their facile realization but most of the techniques are limited to build the micropillars only on totally flat, widely accessible substrate areas with the micropillar’s structural characteristics completely predetermined, leaving little room for in situ control. Here we demonstrate a new technique which overcomes these limitations by directly drawing micropillars from pipette-dispensed PDMS microdroplets using vacuum-chucked microspheres. The combined utilization of PDMS microdroplets and microspheres not only enables the realization of microsphere-tipped PDMS micropillars on non-flat, highly space-constrained substrate areas at in situ controllable heights but also allows arraying of micropillars with dissimilar heights at a close proximity. To validate the new technique’s utility and versatility, we realize PDMS micropillars on various unconventional substrate areas in various configurations. We also convert one of them, the optical fiber/micropillar hybrid, into a soft optical contact sensor. Both the fabrication technique and the resulting sensing scheme will be useful for future biomedical microsystems.
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Affiliation(s)
- Qiang Li
- Department of Electrical and Computer Engineering, Iowa State University, Ames, IA, 50011, USA
| | - Rabin Dhakal
- Department of Electrical and Computer Engineering, Iowa State University, Ames, IA, 50011, USA
| | - Jaeyoun Kim
- Department of Electrical and Computer Engineering, Iowa State University, Ames, IA, 50011, USA.
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35
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Ko H, Seong M, Jeong HE. A micropatterned elastomeric surface with enhanced frictional properties under wet conditions and its application. SOFT MATTER 2017; 13:8419-8425. [PMID: 29082413 DOI: 10.1039/c7sm01493g] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Engineered surfaces that have high friction under wet or lubricated conditions are important in many practical applications. However, it is not easy to achieve stable high friction under wet conditions because a layer of fluid prevents direct solid-solid contact. Here, we report a micropatterned elastomeric surface with superior wet friction. The surface has unique arch-shaped microstructures arrayed in a circle on the surface to provide high friction on wet or flooded surfaces. The arch-shaped micropatterned surface exhibits remarkably enhanced and stable friction under wet conditions, surpassing even the performance of the hexagonal patterns of tree frogs, owing to the large contact surface and the optimal shape of drainage channels. Robotic substrate transportation systems equipped with the micropatterned surfaces can manipulate a delicate wet substrate without any sliding in a highly stable and reproducible manner, demonstrating the superior frictional capabilities of the surface under wet conditions.
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Affiliation(s)
- H Ko
- Department of Mechanical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Republic of Korea.
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36
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Sevcik EN, Szymanski JM, Jallerat Q, Feinberg AW. Patterning on Topography for Generation of Cell Culture Substrates with Independent Nanoscale Control of Chemical and Topographical Extracellular Matrix Cues. CURRENT PROTOCOLS IN CELL BIOLOGY 2017; 75:10.23.1-10.23.25. [PMID: 28627752 PMCID: PMC5548430 DOI: 10.1002/cpcb.25] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The cell microenvironment plays an important role in many biological processes, including development and disease progression. Key to this is the extracellular matrix (ECM), a complex biopolymer network serving as the primary insoluble signaling network for physical, chemical, and mechanical cues. In vitro, the ability to engineer the ECM at the micro- and nanoscales is a critical tool to systematically interrogate the influence of ECM properties on cellular responses. Specifically, both topographical and chemical surface patterning has been shown to direct cell alignment and tissue architecture on biomaterial surfaces, however, it has proven challenging to independently control these surface properties. This protocol describes a method termed Patterning on Topography (PoT) to engineer 2D nanopatterns of ECM proteins onto topographically complex substrates, which enables independent control of physical and chemical surface properties. Applications include interrogation of fundamental cell-surface interactions and engineering interfaces that can direct cell and/or tissue function. © 2017 by John Wiley & Sons, Inc.
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Affiliation(s)
- Emily N. Sevcik
- Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania, USA
| | - John M. Szymanski
- Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania, USA
| | - Quentin Jallerat
- Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania, USA
| | - Adam W. Feinberg
- Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania, USA
- Department of Materials Science and Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania, USA
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37
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Hu H, Tian H, Shao J, Li X, Wang Y, Wang Y, Tian Y, Lu B. Discretely Supported Dry Adhesive Film Inspired by Biological Bending Behavior for Enhanced Performance on a Rough Surface. ACS APPLIED MATERIALS & INTERFACES 2017; 9:7752-7760. [PMID: 28186403 DOI: 10.1021/acsami.6b14951] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Biologically inspired dry adhesion has recently become a research hot topic because of its practical significance in scientific research and instrumental technology. Yet, most of the current studies merely focus on borrowing the concept from some finer biological contact elements but lose sight of the foundation ones that play an equally important role in the adhesion functionality. Inspired by the bending behavior of the flexible foundation element of a gecko (lamellar skin) in attachment motion, in this study, a new type of dry adhesive structure was proposed, wherein a mushroom-shaped micropillar array behaving as a strongly adhesive layer was engineered on a discretely supported thin film. We experimentally observed and analytically modeled the structural deformation and found that the energy penalty could be largely reduced because of the partial shift from pillar bending to film bending. Such behavior is very analogous in functionality to the lamellar skin in a gecko's pads and is helpful in effectively limiting the damage of the contact interface, thus generating enhanced adhesion even on a rough surface.
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Affiliation(s)
- Hong Hu
- Micro/Nanotechnology Research Center, State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University , Xi'an, Shaanxi 710049, China
| | - Hongmiao Tian
- Micro/Nanotechnology Research Center, State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University , Xi'an, Shaanxi 710049, China
| | - Jinyou Shao
- Micro/Nanotechnology Research Center, State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University , Xi'an, Shaanxi 710049, China
| | - Xiangming Li
- Micro/Nanotechnology Research Center, State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University , Xi'an, Shaanxi 710049, China
| | - Yue Wang
- Micro/Nanotechnology Research Center, State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University , Xi'an, Shaanxi 710049, China
| | - Yan Wang
- Micro/Nanotechnology Research Center, State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University , Xi'an, Shaanxi 710049, China
| | - Yu Tian
- State Key Laboratory of Tribology, Tsinghua University , Beijing 10084, China
| | - Bingheng Lu
- Micro/Nanotechnology Research Center, State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University , Xi'an, Shaanxi 710049, China
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38
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Alonso-Redondo E, Gueddida A, Li J, Graczykowski B, Sotomayor Torres CM, Pennec Y, Yang S, Djafari-Rouhani B, Fytas G. Directional elastic wave propagation in high-aspect-ratio photoresist gratings: liquid infiltration and aging. NANOSCALE 2017; 9:2739-2747. [PMID: 28045161 DOI: 10.1039/c6nr08312a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Determination of the mechanical properties of nanostructured soft materials and their composites in a quantitative manner is of great importance to improve the fidelity in their fabrication and to enable the subsequent reliable utility. Here, we report on the characterization of the elastic and photoelastic parameters of a periodic array of nanowalls (grating) by the non-invasive Brillouin light scattering technique and finite element calculations. The resolved elastic vibrational modes in high and low aspect ratio nanowalls reveal quantitative and qualitative differences related to the two-beam interference lithography fabrication and subsequent aging under ambient conditions. The phononic properties, namely the dispersion relations, can be drastically altered by changing the surrounding material of the nanowalls. Here we demonstrate that liquid infiltration turns the phononic function from a single-direction phonon-guiding to an anisotropic propagation along the two orthogonal directions. The susceptibility of the phononic behavior to the infiltrating liquid can be of unusual benefits, such as sensing and alteration of the materials under confinement.
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Affiliation(s)
- E Alonso-Redondo
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany.
| | - A Gueddida
- Institut d'Electronique, de Microélectronique et de Nanotechnologie (IEMN), UMR-CNRS 8520, UFR de Physique, Université de Lille 1, 59655 Villeneuve d'Ascq, France and LPMR, Département de Physique, Faculté des Sciences, Université Mohamed I, 60000 Oujda, Morocco
| | - J Li
- Department of Materials Science and Engineering, University of Pennsylvania, 3231 Walnut Street, Philadelphia, PA 19104, USA
| | - B Graczykowski
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and the Barcelona Institute of Science and Technology, Campus UAB, 08193 Bellaterra, Spain
| | - C M Sotomayor Torres
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and the Barcelona Institute of Science and Technology, Campus UAB, 08193 Bellaterra, Spain and ICREA, Pg. Lluís Companys 23, 08010 Barcelona, Spain
| | - Y Pennec
- Institut d'Electronique, de Microélectronique et de Nanotechnologie (IEMN), UMR-CNRS 8520, UFR de Physique, Université de Lille 1, 59655 Villeneuve d'Ascq, France
| | - S Yang
- Department of Materials Science and Engineering, University of Pennsylvania, 3231 Walnut Street, Philadelphia, PA 19104, USA
| | - B Djafari-Rouhani
- Institut d'Electronique, de Microélectronique et de Nanotechnologie (IEMN), UMR-CNRS 8520, UFR de Physique, Université de Lille 1, 59655 Villeneuve d'Ascq, France
| | - G Fytas
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany. and Department of Materials Science, University of Crete and IESL/FORTH, 71110 Heraklion, Greece
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39
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Tian C, Kim H, Sun W, Kim Y, Yin P, Liu H. DNA Nanostructures-Mediated Molecular Imprinting Lithography. ACS NANO 2017; 11:227-238. [PMID: 28052196 DOI: 10.1021/acsnano.6b04777] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
This paper describes the fabrication of polymer stamps using DNA nanostructure templates. This process creates stamps having diverse nanoscale features with dimensions ranging from several tens of nanometers to micrometers. DNA nanostructures including DNA nanotubes, stretched λ-DNA, two-dimensional (2D) DNA brick crystals with three-dimensional (3D) features, hexagonal DNA 2D arrays, and triangular DNA origami were used as master templates to transfer patterns to poly(methyl methacrylate) and poly(l-lactic acid) with high fidelity. The resulting polymer stamps were used as molds to transfer the pattern to acryloxy perfluoropolyether polymer. This work establishes an approach to using self-assembled DNA templates for applications in soft lithography.
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Affiliation(s)
- Cheng Tian
- Department of Chemistry, University of Pittsburgh , Pittsburgh, Pennsylvania 15260, United States
| | - Hyojeong Kim
- Department of Chemistry, University of Pittsburgh , Pittsburgh, Pennsylvania 15260, United States
| | - Wei Sun
- Wyss Institute for Biologically Inspired Engineering, Harvard University , Boston, Massachusetts 02115, United States
- Department of Systems Biology, Harvard Medical School , Boston, Massachusetts 02115, United States
| | - Yunah Kim
- Department of Chemistry, University of Pittsburgh , Pittsburgh, Pennsylvania 15260, United States
| | - Peng Yin
- Wyss Institute for Biologically Inspired Engineering, Harvard University , Boston, Massachusetts 02115, United States
- Department of Systems Biology, Harvard Medical School , Boston, Massachusetts 02115, United States
| | - Haitao Liu
- Department of Chemistry, University of Pittsburgh , Pittsburgh, Pennsylvania 15260, United States
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40
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Thöle F, Xue L, HEß C, Hillebrand R, Gorb SN, Steinhart M. Quantifying the structural integrity of nanorod arrays. J Microsc 2017; 265:222-231. [PMID: 28094864 DOI: 10.1111/jmi.12491] [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: 06/19/2016] [Revised: 08/23/2016] [Accepted: 09/18/2016] [Indexed: 11/28/2022]
Abstract
Arrays of aligned nanorods oriented perpendicular to a support, which are accessible by top-down lithography or by means of shape-defining hard templates, have received increasing interest as sensor components, components for nanophotonics and nanoelectronics, substrates for tissue engineering, surfaces having specific adhesive or antiadhesive properties and as surfaces with customized wettability. Agglomeration of the nanorods deteriorates the performance of components based on nanorod arrays. A comprehensive body of literature deals with mechanical failure mechanisms of nanorods and design criteria for mechanically stable nanorod arrays. However, the structural integrity of nanorod arrays is commonly evaluated only visually and qualitatively. We use real-space analysis of microscopic images to quantify the fraction of condensed nanorods in nanorod arrays. We suggest the number of array elements apparent in the micrographs divided by the number of array elements a defect-free array would contain in the same area, referred to as integrity fraction, as a measure of structural array integrity. Reproducible procedures to determine the imaged number of array elements are introduced. Thus, quantitative comparisons of different nanorod arrays, or of one nanorod array at different stages of its use, are possible. Structural integrities of identical nanorod arrays differing only in the length of the nanorods are exemplarily analysed.
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Affiliation(s)
- Florian Thöle
- Institut für Chemie neuer Materialien der Universität Osnabrück, Barbarastr. 7, 49069, Osnabrück, Germany
| | - Longjian Xue
- School of Power and Mechanical Engineering, Wuhan University, South Donghu Road 8, Wuhan, Wuchang, 430072, Hubei, China
| | - Claudia HEß
- Institut für Chemie neuer Materialien der Universität Osnabrück, Barbarastr. 7, 49069, Osnabrück, Germany
| | - Reinald Hillebrand
- Max-Planck-Institut für Mikrostrukturphysik, Weinberg 2, 06120, Halle, Germany
| | - Stanislav N Gorb
- Functional Morphology and Biomechanics, Zoological Institute, Kiel University, Am Botanischen Garten 9, 24118, Kiel, Germany
| | - Martin Steinhart
- Institut für Chemie neuer Materialien der Universität Osnabrück, Barbarastr. 7, 49069, Osnabrück, Germany
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41
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Du T, Ma S, Pei X, Wang S, Zhou F. Bio-Inspired Design and Fabrication of Micro/Nano-Brush Dual Structural Surfaces for Switchable Oil Adhesion and Antifouling. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2017; 13:1602020. [PMID: 27511623 DOI: 10.1002/smll.201602020] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Indexed: 05/22/2023]
Abstract
The underwater superoleophobic surfaces play a significant role in anti-oil contamination, marine antifouling, etc. Inspired by the Gecko's feet and its self-cleaning property, a hierarchical structure composed of poly (acrylic acid) gel micro-brushes is designed by the liquid-infused method. This surface exhibits underwater superoleophobicity with very low oil adhesion. It is then modified with stimuli-responsive polymer nano-brushes via surface-initiated atom transfer radical polymerization from the embedded initiator. The micro/nano-brush dual structural surfaces can switch the underwater oil adhesion between low and high while keeping the superoleophobicity. The antifouling properties against algae attachment under different mediums are also investigated to show a strong link between oleophobicity and antibiofouling property. The model surface will be very useful in directing the design of marine self-cleaning coatings to both living and non-living species.
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Affiliation(s)
- Tao Du
- State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, 730000, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Shuanhong Ma
- State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, 730000, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Xiaowei Pei
- State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, 730000, China
| | - Shutao Wang
- Laboratory of Bio-inspired Smart Interface Science, CAS Center for Excellence in Nanoscience, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, 100190, China
| | - Feng Zhou
- State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, 730000, China
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42
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Chen Y, Bi K, Wang Q, Zheng M, Liu Q, Han Y, Yang J, Chang S, Zhang G, Duan H. Rapid Focused Ion Beam Milling Based Fabrication of Plasmonic Nanoparticles and Assemblies via "Sketch and Peel" Strategy. ACS NANO 2016; 10:11228-11236. [PMID: 28024375 DOI: 10.1021/acsnano.6b06290] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Focused ion beam (FIB) milling is a versatile maskless and resistless patterning technique and has been widely used for the fabrication of inverse plasmonic structures such as nanoholes and nanoslits for various applications. However, due to its subtractive milling nature, it is an impractical method to fabricate isolated plasmonic nanoparticles and assemblies which are more commonly adopted in applications. In this work, we propose and demonstrate an approach to reliably and rapidly define plasmonic nanoparticles and their assemblies using FIB milling via a simple "sketch and peel" strategy. Systematic experimental investigations and mechanism studies reveal that the high reliability of this fabrication approach is enabled by a conformally formed sidewall coating due to the ion-milling-induced redeposition. Particularly, we demonstrated that this strategy is also applicable to the state-of-the-art helium ion beam milling technology, with which high-fidelity plasmonic dimers with tiny gaps could be directly and rapidly prototyped. Because the proposed approach enables rapid and reliable patterning of arbitrary plasmonic nanostructures that are not feasible to fabricate via conventional FIB milling process, our work provides the FIB milling technology an additional nanopatterning capability and thus could greatly increase its popularity for utilization in fundamental research and device prototyping.
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Affiliation(s)
| | - Kaixi Bi
- College of Science, National University of Defense Technology , Changsha 410073, People's Republic of China
| | - Qianjin Wang
- College of Engineering and Applied Sciences, Nanjing University , Nanjing 210093, People's Republic of China
| | | | | | - Yunxin Han
- College of Science, National University of Defense Technology , Changsha 410073, People's Republic of China
| | - Junbo Yang
- College of Science, National University of Defense Technology , Changsha 410073, People's Republic of China
| | - Shengli Chang
- College of Science, National University of Defense Technology , Changsha 410073, People's Republic of China
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43
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Lee S, Park B, Kim JS, Kim TI. Designs and processes toward high-aspect-ratio nanostructures at the deep nanoscale: unconventional nanolithography and its applications. NANOTECHNOLOGY 2016; 27:474001. [PMID: 27775918 DOI: 10.1088/0957-4484/27/47/474001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The patterning of high-resolution-featured deep-nanoscale structures with a high aspect ratio (AR) has received increasing attention in recent years as a promising technique for a wide range of applications, including electrical, optical, mechanical and biological systems. Despite extensive efforts to develop viable nanostructure fabrication processes, a superior technique enabling defect-free, high-resolution control over a large area is still required. In this review, we focus on recent important advances in the designs and processes of high-resolution nanostructures possessing a high AR, including hierarchical and 3D patterns. The unique applications of these materials are also discussed.
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Affiliation(s)
- Sori Lee
- School of Chemical Engineering, Sungkyunkwan University (SKKU), Suwon 440-746, Korea
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44
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Xia Y, Cedillo-Servin G, Kamien RD, Yang S. Guided Folding of Nematic Liquid Crystal Elastomer Sheets into 3D via Patterned 1D Microchannels. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2016; 28:9637-9643. [PMID: 27717070 DOI: 10.1002/adma.201603751] [Citation(s) in RCA: 84] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Revised: 08/05/2016] [Indexed: 05/23/2023]
Abstract
Two-dimensional liquid-crystal elastomer (LCE) sheets with preprogrammed topological defects are prepared by aligning liquid-crystal monomers within micropatterned epoxy channels, followed by photopolymerization. Upon heating, the LCE films form various three-dimensional structures in agreement with theoretical design. The miniaturized LCE actuators offer large-area work capacities (≈1.05 J m-2 ) to lift over 700 times their own weight.
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Affiliation(s)
- Yu Xia
- Department of Materials Science and Engineering, University of Pennsylvania, 3231 Walnut Street, Philadelphia, PA, 19104, USA
| | - Gerardo Cedillo-Servin
- Department of Materials Science and Engineering, University of Pennsylvania, 3231 Walnut Street, Philadelphia, PA, 19104, USA
| | - Randall D Kamien
- Department of Physics and Astronomy, University of Pennsylvania, 209 South 33rd St, Philadelphia, PA, 19104, USA
| | - Shu Yang
- Department of Materials Science and Engineering, University of Pennsylvania, 3231 Walnut Street, Philadelphia, PA, 19104, USA
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45
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Muanchan P, Suzuki S, Kyotani T, Ito H. One-dimensional polymer nanofiber arrays with high aspect ratio obtained by thermal nanoimprint method. POLYM ENG SCI 2016. [DOI: 10.1002/pen.24403] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Paritat Muanchan
- Research Center for GREEN Materials and Advanced Processing (GMAP), Graduate School of Science and Engineering; Yamagata University 4-3-16 Jonan; Yonezawa Yamagata 992-8510 Japan
| | - Shohei Suzuki
- Research Center for GREEN Materials and Advanced Processing (GMAP), Graduate School of Science and Engineering; Yamagata University 4-3-16 Jonan; Yonezawa Yamagata 992-8510 Japan
| | - Takashi Kyotani
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University 2-1-1, Katahira; Aoba-Ku Sendai 980-8577 Japan
| | - Hiroshi Ito
- Research Center for GREEN Materials and Advanced Processing (GMAP), Graduate School of Science and Engineering; Yamagata University 4-3-16 Jonan; Yonezawa Yamagata 992-8510 Japan
- Graduate School of Organic Materials Science; Yamagata University 4-3-16 Jonan; Yonezawa Yamagata 992-8510 Japan
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46
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47
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Xia Y, Lee E, Hu H, Gharbi MA, Beller DA, Fleischmann EK, Kamien RD, Zentel R, Yang S. Better Actuation Through Chemistry: Using Surface Coatings to Create Uniform Director Fields in Nematic Liquid Crystal Elastomers. ACS APPLIED MATERIALS & INTERFACES 2016; 8:12466-12472. [PMID: 27152975 DOI: 10.1021/acsami.6b02789] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Controlling the molecular alignment of liquid crystal monomers (LCMs) within nano- and microstructures is essential in manipulating the actuation behavior of nematic liquid crystal elastomers (NLCEs). Here, we study how to induce uniformly vertical alignment of nematic LCMs within a micropillar array to maximize the macroscopic shape change using surface chemistry. Landau-de Gennes numerical modeling suggests that it is difficult to perfectly align LCMs vertically in every pore within a poly(dimethylsiloxane) (PDMS) mold with porous channels during soft lithography. In an untreated PDMS mold that provides homeotropic anchoring of LCMs, a radially escaped configuration of LCMs is observed. Vertically aligned LCMs, a preferred configuration for actuation, are only observed when using a PDMS mold with planar anchoring. Guided by the numerical modeling, we coat the PDMS mold with a thin layer of poly(2-hydroxyethyl methacrylate) (PHEMA), leading to planar anchoring of LCM. Confirmed by polarized optical microscopy, we observe monodomains of vertically aligned LCMs within the mold, in agreement with modeling. After curing and peeling off the mold, the resulting NLCE micropillars showed a relatively large and reversible radial strain (∼30%) when heated above the nematic to isotropic transition temperature.
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Affiliation(s)
- Yu Xia
- Department of Materials Science and Engineering, University of Pennsylvania , 3231 Walnut Street, Philadelphia, Pennsylvania 19104, United States
| | - Elaine Lee
- Department of Materials Science and Engineering, University of Pennsylvania , 3231 Walnut Street, Philadelphia, Pennsylvania 19104, United States
- Engineering Directorate, Lawrence Livermore National Laboratory , 7000 East Avenue, Livermore, California 94550, United States
| | - Hao Hu
- Department of Materials Science and Engineering, University of Pennsylvania , 3231 Walnut Street, Philadelphia, Pennsylvania 19104, United States
| | - Mohamed Amine Gharbi
- Department of Materials Science and Engineering, University of Pennsylvania , 3231 Walnut Street, Philadelphia, Pennsylvania 19104, United States
- Department of Physics and Astronomy, University of Pennsylvania , 209 South 33rd Street, Philadelphia, Pennsylvania 19104, United States
| | - Daniel A Beller
- Paulson School of Engineering and Applied Sciences, Harvard University , 29 Oxford Street, Cambridge, Massachusetts 02138, United States
| | - Eva-Kristina Fleischmann
- Institute of Organic Chemistry, Johannes Gutenberg-Universität Mainz , Duesbergweg 10-14, 55128 Mainz, Germany
| | - Randall D Kamien
- Department of Physics and Astronomy, University of Pennsylvania , 209 South 33rd Street, Philadelphia, Pennsylvania 19104, United States
| | - Rudolf Zentel
- Institute of Organic Chemistry, Johannes Gutenberg-Universität Mainz , Duesbergweg 10-14, 55128 Mainz, Germany
| | - Shu Yang
- Department of Materials Science and Engineering, University of Pennsylvania , 3231 Walnut Street, Philadelphia, Pennsylvania 19104, United States
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48
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Kim T, Park J, Sohn J, Cho D, Jeon S. Bioinspired, Highly Stretchable, and Conductive Dry Adhesives Based on 1D-2D Hybrid Carbon Nanocomposites for All-in-One ECG Electrodes. ACS NANO 2016; 10:4770-8. [PMID: 26986477 DOI: 10.1021/acsnano.6b01355] [Citation(s) in RCA: 150] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Here we propose a concept of conductive dry adhesives (CDA) combining a gecko-inspired hierarchical structure and an elastomeric carbon nanocomposite. To complement the poor electrical percolation of 1D carbon nanotube (CNT) networks in an elastomeric matrix at a low filler content (∼1 wt %), a higher dimensional carbon material (i.e., carbon black, nanographite, and graphene nanopowder) is added into the mixture as an aid filler. The co-doped graphene and CNT in the composite show the lowest volume resistance (∼100 ohm·cm) at an optimized filler ratio (1:9, total filler content: 1 wt %) through a synergetic effect in electrical percolation. With an optimized conductive elastomer, gecko-inspired high-aspect-ratio (>3) microstructures over a large area (∼4 in.(2)) are successfully replicated from intaglio-patterned molds without collapse. The resultant CDA pad shows a high normal adhesion force (∼1.3 N/cm(2)) even on rough human skin and an excellent cycling property for repeatable use over 30 times without degradation of adhesion force, which cannot be achieved by commercial wet adhesives. The body-attachable CDA can be used as a metal-free, all-in-one component for measuring biosignals under daily activity conditions (i.e., underwater, movements) because of its superior conformality and water-repellent characteristic.
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Affiliation(s)
- Taehoon Kim
- Department of Materials Science and Engineering, KAIST Institute for the Nanocentury, KAIST , Daejeon 34141, Republic of Korea
| | - Junyong Park
- Department of Materials Science and Engineering, KAIST Institute for the Nanocentury, KAIST , Daejeon 34141, Republic of Korea
| | - Jongmoo Sohn
- Wearable Computing Research Team, ETRI , Daejeon 34129, Republic of Korea
| | - Donghwi Cho
- Department of Materials Science and Engineering, KAIST Institute for the Nanocentury, KAIST , Daejeon 34141, Republic of Korea
| | - Seokwoo Jeon
- Department of Materials Science and Engineering, KAIST Institute for the Nanocentury, KAIST , Daejeon 34141, Republic of Korea
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49
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Liu H, Lei B, Jiang W, Li Y, Yin L, Chen B, Shi Y. Ultrasound-assisted recovery of free-standing high-aspect-ratio micropillars. RSC Adv 2016. [DOI: 10.1039/c5ra26898b] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
High-aspect-ratio polymer micropillar arrays are widely employed in microfluidics and microdevices.
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Affiliation(s)
- Hongzhong Liu
- State Key Laboratory for Manufacturing Systems Engineering
- Xi'an Jiaotong University
- Xi'an 710049
- China
| | - Biao Lei
- State Key Laboratory for Manufacturing Systems Engineering
- Xi'an Jiaotong University
- Xi'an 710049
- China
| | - Weitao Jiang
- State Key Laboratory for Manufacturing Systems Engineering
- Xi'an Jiaotong University
- Xi'an 710049
- China
| | - Yonghao Li
- State Key Laboratory for Manufacturing Systems Engineering
- Xi'an Jiaotong University
- Xi'an 710049
- China
| | - Lei Yin
- State Key Laboratory for Manufacturing Systems Engineering
- Xi'an Jiaotong University
- Xi'an 710049
- China
| | - Bangdao Chen
- State Key Laboratory for Manufacturing Systems Engineering
- Xi'an Jiaotong University
- Xi'an 710049
- China
| | - Yongsheng Shi
- State Key Laboratory for Manufacturing Systems Engineering
- Xi'an Jiaotong University
- Xi'an 710049
- China
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50
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Lao Z, Hu Y, Zhang C, Yang L, Li J, Chu J, Wu D. Capillary Force Driven Self-Assembly of Anisotropic Hierarchical Structures Prepared by Femtosecond Laser 3D Printing and Their Applications in Crystallizing Microparticles. ACS NANO 2015; 9:12060-9. [PMID: 26506428 DOI: 10.1021/acsnano.5b04914] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
The hierarchical structures are the derivation of various functionalities in the natural world and have inspired broad practical applications in chemical systhesis and biological manipulation. However, traditional top-down fabrication approaches suffered from low complexity. We propose a laser printing capillary-assisted self-assembly (LPCS) strategy for fabricating regular periodic structures. Microscale pillars are first produced by the localized femtosecond laser polymerization and are subsequently self-assembled into periodic hierarchical architectures with the assistance of controlled capillary force. Moreover, based on anisotropic assemblies of micropillars, the LPCS method is further developed for the preparation of more complicated and advanced functional microstructures. Pillars cross section, height, and spatial arrangement can be tuned to guide capillary force, and diverse assemblies with different configurations are thus achieved. Finally, we developed a strategy for growing micro/nanoparticles in designed spatial locations through solution-evaporation self-assembly induced by morphology. Due to the high flexibility of LPCS method, the special arrangements, sizes, and distribution density of the micro/nanoparticles can be controlled readily. Our method will be employed not only to fabricate anisotropic hierarchical structures but also to design and manufacture organic/inorganic microparticles.
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Affiliation(s)
- Zhaoxin Lao
- CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China , Hefei, Anhui 230027, China
| | - Yanlei Hu
- CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China , Hefei, Anhui 230027, China
| | - Chenchu Zhang
- CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China , Hefei, Anhui 230027, China
| | - Liang Yang
- CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China , Hefei, Anhui 230027, China
| | - Jiawen Li
- CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China , Hefei, Anhui 230027, China
| | - Jiaru Chu
- CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China , Hefei, Anhui 230027, China
| | - Dong Wu
- CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China , Hefei, Anhui 230027, China
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