1
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Bauer J, Crook C, Baldacchini T. A sinterless, low-temperature route to 3D print nanoscale optical-grade glass. Science 2023; 380:960-966. [PMID: 37262172 DOI: 10.1126/science.abq3037] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Accepted: 04/12/2023] [Indexed: 06/03/2023]
Abstract
Three-dimensional (3D) printing of silica glass is dominated by techniques that rely on traditional particle sintering. At the nanoscale, this limits their adoption within microsystem technology, which prevents technological breakthroughs. We introduce the sinterless, two-photon polymerization 3D printing of free-form fused silica nanostructures from a polyhedral oligomeric silsesquioxane (POSS) resin. Contrary to particle-loaded sacrificial binders, our POSS resin itself constitutes a continuous silicon-oxygen molecular network that forms transparent fused silica at only 650°C. This temperature is 500°C lower than the sintering temperatures for fusing discrete silica particles to a continuum, which brings silica 3D printing below the melting points of essential microsystem materials. Simultaneously, we achieve a fourfold resolution enhancement, which enables visible light nanophotonics. By demonstrating excellent optical quality, mechanical resilience, ease of processing, and coverable size scale, our material sets a benchmark for micro- and nano-3D printing of inorganic solids.
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Affiliation(s)
- J Bauer
- Institute of Nanotechnology, Karlsruhe Institute of Technology, 76131 Karlsruhe, Germany
- Materials Science and Engineering Department, University of California, Irvine, CA 94550, USA
| | - C Crook
- Materials Science and Engineering Department, University of California, Irvine, CA 94550, USA
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2
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Catt SO, Hackner M, Spatz JP, Blasco E. Macromolecular Engineering: From Precise Macromolecular Inks to 3D Printed Microstructures. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2023:e2300844. [PMID: 37078908 DOI: 10.1002/smll.202300844] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 03/16/2023] [Indexed: 05/03/2023]
Abstract
Macromolecules with complex, defined structures exist in nature but rarely is this degree of control afforded in synthetic macromolecules. Sequence-defined approaches provide a solution for precise control of the primary macromolecular structure. Despite a growing interest, very few examples for applications of sequence-defined macromolecules exist. In particular, the use of sequence-defined macromolecules as printable materials remains unexplored. Herein, the rational design of precise macromolecular inks for 3D microprinting is investigated for the first time. Specifically, three printable oligomers are synthesized, consisting of eight units, either crosslinkable (C) or non-functional (B) with varied sequence (BCBCBCBC, alternating; BBCCCBB, triblock; and BBBBCCCC, block). The oligomers are printed using two-photon laser printing and characterized. It is clearly demonstrated that the macromolecular sequence, specifically the positioning of the crosslinkable group, plays a critical role in both the printability and final properties of the printed material. Thus, through precise design and printability of sequence-defined macromolecules, an exciting avenue for the next generation of functional materials for 3D printing is created.
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Affiliation(s)
- Samantha O Catt
- Institute for Molecular Systems Engineering and Advanced Materials (IMSEAM) and Organic Chemistry Institute (OCI), Heidelberg University, 69120, Heidelberg, Germany
| | - Maximillian Hackner
- Institute for Molecular Systems Engineering and Advanced Materials (IMSEAM) and Organic Chemistry Institute (OCI), Heidelberg University, 69120, Heidelberg, Germany
- Department of Cellular Biophysics, Germany Max Planck Institute for Medical Research, 69120, Heidelberg, Germany
| | - Joachim P Spatz
- Institute for Molecular Systems Engineering and Advanced Materials (IMSEAM) and Organic Chemistry Institute (OCI), Heidelberg University, 69120, Heidelberg, Germany
- Department of Cellular Biophysics, Germany Max Planck Institute for Medical Research, 69120, Heidelberg, Germany
| | - Eva Blasco
- Institute for Molecular Systems Engineering and Advanced Materials (IMSEAM) and Organic Chemistry Institute (OCI), Heidelberg University, 69120, Heidelberg, Germany
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3
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Groetsch A, Stelzl S, Nagel Y, Kochetkova T, Scherrer NC, Ovsianikov A, Michler J, Pethö L, Siqueira G, Nyström G, Schwiedrzik J. Microscale 3D Printing and Tuning of Cellulose Nanocrystals Reinforced Polymer Nanocomposites. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2023; 19:e2202470. [PMID: 36449596 DOI: 10.1002/smll.202202470] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Revised: 11/04/2022] [Indexed: 06/17/2023]
Abstract
The increasing demand for functional materials and an efficient use of sustainable resources makes the search for new material systems an ever growing endeavor. With this respect, architected (meta-)materials attract considerable interest. Their fabrication at the micro- and nanoscale, however, remains a challenge, especially for composites with highly different phases and unmodified reinforcement fillers. This study demonstrates that it is possible to create a non-cytotoxic nanocomposite ink reinforced by a sustainable phase, cellulose nanocrystals (CNCs), to print and tune complex 3D architectures using two-photon polymerization, thus, advancing the state of knowledge toward the microscale. Micro-compression, high-res scanning electron microscopy, (polarised) Raman spectroscopy, and composite modeling are used to study the structure-property relationships. A 100% stiffness increase is observed already at 4.5 wt% CNC while reaching a high photo-polymerization degree of ≈80% for both neat polymers and CNC-composites. Polarized Raman and the Halpin-Tsai composite-model suggest a random CNC orientation within the polymer matrix. The microscale approach can be used to tune arbitrary small scale CNC-reinforced polymer-composites with comparable feature sizes. The new insights pave the way for future applications where the 3D printing of small structures is essential to improve performances of tissue-scaffolds, extend bio-electronics applications or tailor microscale energy-absorption devices.
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Affiliation(s)
- Alexander Groetsch
- Laboratory for Mechanics of Materials and Nanostructures Department of Advanced Materials and Surfaces, Empa - Swiss Federal Laboratories for Materials Science and Technology, Feuerwerkerstrasse 39, Thun, 3602, Switzerland
| | - Samuel Stelzl
- Research Group 3D Printing and Biofabrication Institute of Materials Science and Technology, TU Wien, Getreidemarkt 9, Vienna, 1060, Austria
| | - Yannick Nagel
- Laboratory for Cellulose & Wood Materials, Empa - Swiss Federal Laboratories for Materials Science and Technology, Ueberlandstrasse 129, Dübendorf, 8600, Switzerland
| | - Tatiana Kochetkova
- Laboratory for Mechanics of Materials and Nanostructures Department of Advanced Materials and Surfaces, Empa - Swiss Federal Laboratories for Materials Science and Technology, Feuerwerkerstrasse 39, Thun, 3602, Switzerland
| | - Nadim C Scherrer
- Bern University of Applied Sciences, HKB, Bern, 3027, Switzerland
| | - Aleksandr Ovsianikov
- Research Group 3D Printing and Biofabrication Institute of Materials Science and Technology, TU Wien, Getreidemarkt 9, Vienna, 1060, Austria
| | - Johann Michler
- Laboratory for Mechanics of Materials and Nanostructures Department of Advanced Materials and Surfaces, Empa - Swiss Federal Laboratories for Materials Science and Technology, Feuerwerkerstrasse 39, Thun, 3602, Switzerland
| | - Laszlo Pethö
- Laboratory for Mechanics of Materials and Nanostructures Department of Advanced Materials and Surfaces, Empa - Swiss Federal Laboratories for Materials Science and Technology, Feuerwerkerstrasse 39, Thun, 3602, Switzerland
| | - Gilberto Siqueira
- Laboratory for Cellulose & Wood Materials, Empa - Swiss Federal Laboratories for Materials Science and Technology, Ueberlandstrasse 129, Dübendorf, 8600, Switzerland
| | - Gustav Nyström
- Laboratory for Cellulose & Wood Materials, Empa - Swiss Federal Laboratories for Materials Science and Technology, Ueberlandstrasse 129, Dübendorf, 8600, Switzerland
- Department of Health Sciences and Technology, ETH Zurich, Universitätstrasse 2, Zurich, 8092, Switzerland
| | - Jakob Schwiedrzik
- Laboratory for Mechanics of Materials and Nanostructures Department of Advanced Materials and Surfaces, Empa - Swiss Federal Laboratories for Materials Science and Technology, Feuerwerkerstrasse 39, Thun, 3602, Switzerland
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4
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Challenges and limits of mechanical stability in 3D direct laser writing. Nat Commun 2022; 13:2115. [PMID: 35440637 PMCID: PMC9018765 DOI: 10.1038/s41467-022-29749-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Accepted: 03/08/2022] [Indexed: 11/16/2022] Open
Abstract
Direct laser writing is an effective technique for fabrication of complex 3D polymer networks using ultrashort laser pulses. Practically, it remains a challenge to design and fabricate high performance materials with different functions that possess a combination of high strength, substantial ductility, and tailored functionality, in particular for small feature sizes. To date, it is difficult to obtain a time-resolved microscopic picture of the printing process in operando. To close this gap, we herewith present a molecular dynamics simulation approach to model direct laser writing and investigate the effect of writing condition and aspect ratio on the mechanical properties of the printed polymer network. We show that writing conditions provide a possibility to tune the mechanical properties and an optimum writing condition can be applied to fabricate structures with improved mechanical properties. We reveal that beyond the writing parameters, aspect ratio plays an important role to tune the stiffness of the printed structures. Direct laser writing is an effective technique for fabrication of complex 3D polymer networks using ultrashort laser pulses but to date it is difficult to obtain a time-resolved microscopic picture of the printing process in operando. Here, the use molecular dynamics simulation to model direct laser writing and investigate the effect of writing condition and aspect ratio on the mechanical properties of the printed polymer network.
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5
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Kubacková J, Slabý C, Horvath D, Hovan A, Iványi GT, Vizsnyiczai G, Kelemen L, Žoldák G, Tomori Z, Bánó G. Assessing the Viscoelasticity of Photopolymer Nanowires Using a Three-Parameter Solid Model for Bending Recovery Motion. NANOMATERIALS (BASEL, SWITZERLAND) 2021; 11:2961. [PMID: 34835725 PMCID: PMC8618069 DOI: 10.3390/nano11112961] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Revised: 10/27/2021] [Accepted: 11/01/2021] [Indexed: 12/26/2022]
Abstract
Photopolymer nanowires prepared by two-photon polymerization direct laser writing (TPP-DLW) are the building blocks of many microstructure systems. These nanowires possess viscoelastic characteristics that define their deformations under applied forces when operated in a dynamic regime. A simple mechanical model was previously used to describe the bending recovery motion of deflected nanowire cantilevers in Newtonian liquids. The inverse problem is targeted in this work; the experimental observations are used to determine the nanowire physical characteristics. Most importantly, based on the linear three-parameter solid model, we derive explicit formulas to calculate the viscoelastic material parameters. It is shown that the effective elastic modulus of the studied nanowires is two orders of magnitude lower than measured for the bulk material. Additionally, we report on a notable effect of the surrounding aqueous glucose solution on the elasticity and the intrinsic viscosity of the studied nanowires made of Ormocomp.
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Affiliation(s)
- Jana Kubacková
- Department of Biophysics, Institute of Experimental Physics SAS, Watsonova 47, 040 01 Košice, Slovakia; (J.K.); (Z.T.)
| | - Cyril Slabý
- Department of Biophysics, Faculty of Science, P. J. Šafárik University, Jesenná 5, 041 54 Košice, Slovakia; (C.S.); (A.H.)
| | - Denis Horvath
- Center for Interdisciplinary Biosciences, Technology and Innovation Park, P. J. Šafárik University, Jesenná 5, 041 54 Košice, Slovakia; (D.H.); (G.Ž.)
| | - Andrej Hovan
- Department of Biophysics, Faculty of Science, P. J. Šafárik University, Jesenná 5, 041 54 Košice, Slovakia; (C.S.); (A.H.)
| | - Gergely T. Iványi
- Faculty of Science and Informatics, University of Szeged, Dugonics Square 13, 6720 Szeged, Hungary;
- Biological Research Centre, Institute of Biophysics, Eötvös Loránd Research Network (ELKH), Temesvári krt. 62, 6726 Szeged, Hungary; (G.V.); (L.K.)
| | - Gaszton Vizsnyiczai
- Biological Research Centre, Institute of Biophysics, Eötvös Loránd Research Network (ELKH), Temesvári krt. 62, 6726 Szeged, Hungary; (G.V.); (L.K.)
| | - Lóránd Kelemen
- Biological Research Centre, Institute of Biophysics, Eötvös Loránd Research Network (ELKH), Temesvári krt. 62, 6726 Szeged, Hungary; (G.V.); (L.K.)
| | - Gabriel Žoldák
- Center for Interdisciplinary Biosciences, Technology and Innovation Park, P. J. Šafárik University, Jesenná 5, 041 54 Košice, Slovakia; (D.H.); (G.Ž.)
| | - Zoltán Tomori
- Department of Biophysics, Institute of Experimental Physics SAS, Watsonova 47, 040 01 Košice, Slovakia; (J.K.); (Z.T.)
| | - Gregor Bánó
- Department of Biophysics, Faculty of Science, P. J. Šafárik University, Jesenná 5, 041 54 Košice, Slovakia; (C.S.); (A.H.)
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6
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Jaiswal A, Rani S, Singh GP, Hassan M, Nasrin A, Gomes VG, Saxena S, Shukla S. Additive-Free All-Carbon Composite: A Two-Photon Material System for Nanopatterning of Fluorescent Sub-Wavelength Structures. ACS NANO 2021; 15:14193-14206. [PMID: 34435496 DOI: 10.1021/acsnano.1c01083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
The major bottleneck in fabrication of engineered 3D nanostructures is the choice of materials. Adding functionality to these nanostructures is a daunting task. In order to mitigate these issues, we report a two-photon patternable all carbon material system which can be used to fabricate fluorescent 3D micro/nanostructures using two-photon lithography, with subwavelength resolution. The synthesized material system eliminates the need to use conventional two-photon absorbing materials such as two-photon dyes or two-photon initiators. We have used two different trifunctional acrylate monomers and carbon dots, synthesized hydrothermally from a polyphenolic precursor, to formulate a two-photon processable resin. Upon two-photon excitation, photogenerated electrons in the excited states of the carbon dots facilitate the free radical formation at the surface of the carbon dots. These radicals, upon interaction with vinyl moieties, enable cross-linking of acrylate monomers. Free-radical induced two-photon polymerization of acrylate monomers without any conventional proprietary two-photon absorbing materials was accomplished at an ultrafine subwavelength resolution of 250 nm using 800 nm laser excitation. The effect of critical parameters such as average laser power, carbon dot concentration, and radiation exposure were determined for the fabrication of one-, two-, and three-dimensional functional nanostructures, applicable in a range of domains where fluorescence and toxicity are of the utmost importance. A fabrication speed as high as 100 mm/s was achieved. The ability to fabricate functional 3D micro-/nanostructures is anticipated to instigate a paradigm shift in various areas such as metamaterials, energy storage, drug delivery, and optoelectronics to name a few.
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Affiliation(s)
- Arun Jaiswal
- Nanostructures Engineering and Modeling Laboratory, Department of Metallurgical Engineering and Materials Science, Indian Institute of Technology Bombay, Mumbai 400076, Maharashtra, India
| | - Sweta Rani
- Nanostructures Engineering and Modeling Laboratory, Department of Metallurgical Engineering and Materials Science, Indian Institute of Technology Bombay-Monash Research Academy, Mumbai 400076, Maharashtra, India
| | - Gaurav Pratap Singh
- Nanostructures Engineering and Modeling Laboratory, Department of Metallurgical Engineering and Materials Science, Indian Institute of Technology Bombay, Mumbai 400076, Maharashtra, India
| | - Mahbub Hassan
- School of Chemical and Biomolecular Engineering, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Aklima Nasrin
- School of Chemical and Biomolecular Engineering, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Vincent G Gomes
- School of Chemical and Biomolecular Engineering, The University of Sydney, Sydney, New South Wales 2006, Australia
- Nano Institute, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Sumit Saxena
- Nanostructures Engineering and Modeling Laboratory, Department of Metallurgical Engineering and Materials Science, Indian Institute of Technology Bombay, Mumbai 400076, Maharashtra, India
- Nanostructures Engineering and Modeling Laboratory, Department of Metallurgical Engineering and Materials Science, Indian Institute of Technology Bombay-Monash Research Academy, Mumbai 400076, Maharashtra, India
| | - Shobha Shukla
- Nanostructures Engineering and Modeling Laboratory, Department of Metallurgical Engineering and Materials Science, Indian Institute of Technology Bombay, Mumbai 400076, Maharashtra, India
- Nanostructures Engineering and Modeling Laboratory, Department of Metallurgical Engineering and Materials Science, Indian Institute of Technology Bombay-Monash Research Academy, Mumbai 400076, Maharashtra, India
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7
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Xu S, Camp CH, Lee YJ. Coherent
anti‐Stokes
Raman scattering microscopy for polymers. JOURNAL OF POLYMER SCIENCE 2021. [DOI: 10.1002/pol.20210317] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Shuyu Xu
- Biosystems and Biomaterials Division National Institute of Standards and Technology Gaithersburg Maryland USA
| | - Charles H. Camp
- Biosystems and Biomaterials Division National Institute of Standards and Technology Gaithersburg Maryland USA
| | - Young Jong Lee
- Biosystems and Biomaterials Division National Institute of Standards and Technology Gaithersburg Maryland USA
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8
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Bauer J, Izard AG, Zhang Y, Baldacchini T, Valdevit L. Thermal post-curing as an efficient strategy to eliminate process parameter sensitivity in the mechanical properties of two-photon polymerized materials. OPTICS EXPRESS 2020; 28:20362-20371. [PMID: 32680097 DOI: 10.1364/oe.395986] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Accepted: 06/10/2020] [Indexed: 06/11/2023]
Abstract
Two-photon polymerization direct laser writing (TPP-DLW) is one of the most versatile technologies to additively manufacture complex parts with nanoscale resolution. However, the wide range of mechanical properties that results from the chosen combination of multiple process parameters imposes an obstacle to its widespread use. Here we introduce a thermal post-curing route as an effective and simple method to increase the mechanical properties of acrylate-based TPP-DLW-derived parts by 20-250% and to largely eliminate the characteristic coupling of processing parameters, material properties and part functionality. We identify the underlying mechanism of the property enhancement as a self-initiated thermal curing reaction, which robustly facilitates the high property reproducibility that is essential for any application of TPP-DLW.
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9
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Serien D, Sugioka K. Three-Dimensional Printing of Pure Proteinaceous Microstructures by Femtosecond Laser Multiphoton Cross-Linking. ACS Biomater Sci Eng 2020; 6:1279-1287. [PMID: 33464859 DOI: 10.1021/acsbiomaterials.9b01619] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Laser direct write (LDW) is a promising three-dimensional (3D) printing technology for creating proteinaceous microstructures in which the proteins retain their original function, enabling the manufacture of complex biomimetic 3D microenvironments and versatile enhancement of medical microdevices. A photoactivator has commonly been used to date in the laser direct write of proteins to enhance the cross-linking process. However, incomplete conversion results in photoactivator molecules remaining trapped inside the protein microstructure, causing their gradual leaching and subsequent undesirable effect on biological applications. Here, we demonstrate the 3D fabrication of microstructures made of pure serum albumin protein using photoactivator-free fabrication, confirmed by Raman data. For the first time, acid-catalyzed hydrolysis of the created structures provides evidence that chemical cross-links are induced by exposure to femtosecond laser irradiation. The diversity of the biomaterial protein available for the precursors for LDW offers capability of the fabrication of complex biomimetic 3D microenvironments and biochip applications.
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Affiliation(s)
- Daniela Serien
- RIKEN Center for Advanced Photonics, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Koji Sugioka
- RIKEN Center for Advanced Photonics, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
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10
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Two-Photon Polymerization Metrology: Characterization Methods of Mechanisms and Microstructures. MICROMACHINES 2017. [PMCID: PMC6189958 DOI: 10.3390/mi8040101] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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11
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Oakdale JS, Ye J, Smith WL, Biener J. Post-print UV curing method for improving the mechanical properties of prototypes derived from two-photon lithography. OPTICS EXPRESS 2016; 24:27077-27086. [PMID: 27906282 DOI: 10.1364/oe.24.027077] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Two photon polymerization (TPP) is a precise, reliable, and increasingly popular technique for rapid prototyping of micro-scale parts with sub-micron resolution. The materials of choice underlying this process are predominately acrylic resins cross-linked via free-radical polymerization. Due to the nature of the printing process, the derived parts are only partially cured and the corresponding mechanical properties, i.e. modulus and ultimate strength, are lower than if the material were cross-linked to the maximum extent. Herein, post-print curing via UV-driven radical generation, is demonstrated to increase the overall degree of cross-linking of low density, TPP-derived structures.
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12
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Jiang L, Xiong W, Zhou Y, Liu Y, Huang X, Li D, Baldacchini T, Jiang L, Lu Y. Performance comparison of acrylic and thiol-acrylic resins in two-photon polymerization. OPTICS EXPRESS 2016; 24:13687-701. [PMID: 27410383 DOI: 10.1364/oe.24.013687] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Microfabrication by two-photon polymerization is investigated using resins based on thiol-ene chemistry. In particular, resins containing different amounts of a tetrafunctional acrylic monomer and a tetrafunctional thiol molecule are used to create complex microstructures. We observe the enhancement of several characteristics of two-photon polymerization when using thiol-acrylic resins. Specifically, microfabrication is carried out using higher writing velocities and it produces stronger polymeric microstructures. Furthermore, the amount of shrinkage typically observed in the production of three-dimensional microstructures is reduced also. By means of microspectrometry, we confirm that the thiol-acrylate mixture in TPP resins promote monomer conversion inducing a higher degree of cross-linked network formation.
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13
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Kunwar P, Toivonen J, Kauranen M, Bautista G. Third-harmonic generation imaging of three-dimensional microstructures fabricated by photopolymerization. OPTICS EXPRESS 2016; 24:9353-9358. [PMID: 27137551 DOI: 10.1364/oe.24.009353] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
We demonstrate the capability of polarized third-harmonic generation (THG) for high contrast imaging of three-dimensional microstructures fabricated by photopolymerization. Using circular polarization of fundamental light, background-free optically-sectioned THG images were obtained from laser-written photopolymerized microstructures. The technique has great potential for simple and noninvasive characterization of photopolymerized devices, which typically show poor contrast in conventional light microscopy.
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14
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Camp CH, Lee YJ, Cicerone MT. Quantitative, Comparable Coherent Anti-Stokes Raman Scattering (CARS) Spectroscopy: Correcting Errors in Phase Retrieval. JOURNAL OF RAMAN SPECTROSCOPY : JRS 2016; 47:408-415. [PMID: 28819335 PMCID: PMC5557306 DOI: 10.1002/jrs.4824] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Coherent anti-Stokes Raman scattering (CARS) microspectroscopy has demonstrated significant potential for biological and materials imaging. To date, however, the primary mechanism of disseminating CARS spectroscopic information is through pseudocolor imagery, which explicitly neglects a vast majority of the hyperspectral data. Furthermore, current paradigms in CARS spectral processing do not lend themselves to quantitative sample-to-sample comparability. The primary limitation stems from the need to accurately measure the so-called nonresonant background (NRB) that is used to extract the chemically-sensitive Raman information from the raw spectra. Measurement of the NRB on a pixel-by-pixel basis is a nontrivial task; thus, reference NRB from glass or water are typically utilized, resulting in error between the actual and estimated amplitude and phase. In this manuscript, we present a new methodology for extracting the Raman spectral features that significantly suppresses these errors through phase detrending and scaling. Classic methods of error-correction, such as baseline detrending, are demonstrated to be inaccurate and to simply mask the underlying errors. The theoretical justification is presented by re-developing the theory of phase retrieval via the Kramers-Kronig relation, and we demonstrate that these results are also applicable to maximum entropy method-based phase retrieval. This new error-correction approach is experimentally applied to glycerol spectra and tissue images, demonstrating marked consistency between spectra obtained using different NRB estimates, and between spectra obtained on different instruments. Additionally, in order to facilitate implementation of these approaches, we have made many of the tools described herein available free for download.
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15
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Winterhalder MJ, Zumbusch A. Beyond the borders--Biomedical applications of non-linear Raman microscopy. Adv Drug Deliv Rev 2015; 89:135-44. [PMID: 25959426 DOI: 10.1016/j.addr.2015.04.024] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2015] [Revised: 04/17/2015] [Accepted: 04/29/2015] [Indexed: 11/26/2022]
Abstract
Raman spectroscopy offers great promise for label free imaging in biomedical applications. Its use, however, is hampered by the long integration times required and the presence of autofluorescence in many samples which outshines the Raman signals. In order to overcome these limitations, a variety of different non-linear Raman imaging techniques have been developed over the last decade. This review describes biomedical applications of these novel but already mature imaging techniques.
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16
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Jiang LJ, Zhou YS, Xiong W, Gao Y, Huang X, Jiang L, Baldacchini T, Silvain JF, Lu YF. Two-photon polymerization: investigation of chemical and mechanical properties of resins using Raman microspectroscopy. OPTICS LETTERS 2014; 39:3034-7. [PMID: 24978266 DOI: 10.1364/ol.39.003034] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
In this study, the degree of conversion (DC) of an acrylic-based resin (IP-L 780) in two-photon polymerization (TPP) is systematically investigated via Raman microspectroscopy. A quantitative relationship between TPP laser parameters and the DC of the resin is established. Nonlinear increase in DC with increased laser average power is observed. The resin DC is more sensitive to the laser average power than the laser writing speed. Nanoindentation was employed to correlate the results obtained from Raman microspectroscopy with the mechanical properties of microstructures fabricated by TPP. At constant writing speeds, microstructures fabricated with high laser average powers possess high hardness and high reduced Young's modulus (RYM), indicating high DCs. The results are in line with high DCs measured under the same TPP parameters in Raman microspectroscopy. Raman microspectroscopy is proved to be an effective, rapid, and nondestructive method characterizing microstructures fabrication by TPP.
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17
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Baldacchini T, Snider S, Zadoyan R. Two-photon polymerization with variable repetition rate bursts of femtosecond laser pulses. OPTICS EXPRESS 2012; 20:29890-29899. [PMID: 23388815 DOI: 10.1364/oe.20.029890] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
We describe fabrication of microstructures by two-photon polymerization using bursts of femtosecond laser pulses. With the aid of an acousto-optic modulator driven by a function generator, two-photon polymerization is performed at variable burst repetition rates. We investigate how the time between the bursts of laser pulses influences the ultimate dimensions of lines written in a photosensitive resin. We observe that when using the same laser fluence, polymer lines fabricated at different burst repetition rates have different dimensions. In particular, the widths of two-photon polymerized lines become smaller with decreasing burst repetition rates. Based on the thermal properties of the resin and experimental writing conditions, we attribute this effect to localized heat accumulation.
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Affiliation(s)
- Tommaso Baldacchini
- Technology and Applications Center, Newport Corporation, 1791 Deere Avenue, Irvine, California 92606, USA
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18
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He XN, Allen J, Black PN, Baldacchini T, Huang X, Huang H, Jiang L, Lu YF. Coherent anti-Stokes Raman scattering and spontaneous Raman spectroscopy and microscopy of microalgae with nitrogen depletion. BIOMEDICAL OPTICS EXPRESS 2012; 3:2896-906. [PMID: 23162727 PMCID: PMC3493223 DOI: 10.1364/boe.3.002896] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2012] [Revised: 10/13/2012] [Accepted: 10/15/2012] [Indexed: 05/04/2023]
Abstract
Microalgae are extensively researched as potential feedstocks for biofuel production. Energy-rich compounds in microalgae, such as lipids, require efficient characterization techniques to investigate the metabolic pathways and the environmental factors influencing their accumulation. The model green alga Coccomyxa accumulates significant amounts of triacylglycerols (TAGs) under nitrogen depletion (N-depletion). To monitor the growth of TAGs (lipid) in microalgal cells, a study of microalgal cells (Coccomyxa sp. C169) using both spontaneous Raman and coherent anti-Stokes Raman scattering (CARS) spectroscopy and microscopy were carried out. Spontaneous Raman spectroscopy was conducted to analyze the components in the algal cells, while CARS was carried out to monitor the distribution of lipid droplets in the cells. Raman signals of carotenoid are greater in control microalgae compared to N-depleted cells. Raman signals of lipid droplets appear after N-depletion and its distribution can be clearly observed in the CARS microscopy. Both spontaneous Raman spectroscopy and CARS microscopy were found to be suitable analysis tools for microalgae.
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Affiliation(s)
- X. N. He
- Department of Electrical Engineering, University of Nebraska-Lincoln, Lincoln, NE 68588-0511, USA
| | - J. Allen
- Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, NE 68588-0664, USA
| | - P. N. Black
- Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, NE 68588-0664, USA
| | - T. Baldacchini
- Department of Electrical Engineering, University of Nebraska-Lincoln, Lincoln, NE 68588-0511, USA
- Technology and Applications Center, Newport Corporation, Irvine, CA 92606, USA
| | - X. Huang
- Department of Electrical Engineering, University of Nebraska-Lincoln, Lincoln, NE 68588-0511, USA
| | - H. Huang
- Department of Electrical Engineering, University of Nebraska-Lincoln, Lincoln, NE 68588-0511, USA
| | - L. Jiang
- Department of Mechanical and Automation Engineering, Beijing Institute of Technology, Beijing, 100081, China
| | - Y. F. Lu
- Department of Electrical Engineering, University of Nebraska-Lincoln, Lincoln, NE 68588-0511, USA
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19
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Baldacchini T, Zadoyan R. In situ and real time monitoring of two-photon polymerization using broadband coherent anti-Stokes Raman scattering microscopy. OPTICS EXPRESS 2010; 18:19219-31. [PMID: 20940818 DOI: 10.1364/oe.18.019219] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
We demonstrate in situ and real time characterization of two-photon polymerization (TPP) by means of broadband coherent anti-Stokes Raman scattering (CARS) microscopy. The same experimental setup based on one femtosecond oscillator is used to perform both TPP and broadband CARS microscopy. We performed in situ imaging with chemical specificity of three-dimensional microstructures fabricated by TPP, and successfully followed the writing process in real time. Broadband CARS microscopy allowed discerning between polymerized and unpolymerized material. Imaging with good vibrational contrast is achieved without causing any damage to the microstructures or undesired polymerization within the sample.
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Affiliation(s)
- Tommaso Baldacchini
- Technology and Applications Center, Newport Corporation, 1791 Deere Avenue, Irvine, CA 92606, USA
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20
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Vogler N, Bocklitz T, Mariani M, Deckert V, Markova A, Schelkens P, Rösch P, Akimov D, Dietzek B, Popp J. Separation of CARS image contributions with a Gaussian mixture model. JOURNAL OF THE OPTICAL SOCIETY OF AMERICA. A, OPTICS, IMAGE SCIENCE, AND VISION 2010; 27:1361-1371. [PMID: 20508705 DOI: 10.1364/josaa.27.001361] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Coherent anti-Stokes Raman scattering (CARS) gained a lot of importance in chemical imaging. This is due to the fast image acquisition time, the high spatial resolution, the non-invasiveness, and the molecular sensitivity of this method. By using the single-line CARS in contrast to the multiplex CARS, different signal contributions stemming from resonant and non-resonant light-matter interactions are indistinguishable. Here a numerical method is presented in order to extract more information from univariate CARS images: vibrational composition, morphological information, and contributions from index-of-refraction steps can be separated from single-line CARS images. The image processing algorithm is based on the physical properties of CARS process as reflected in the shape of the intensity histogram of univariate CARS images. Because of this the comparability of individual CARS images recorded with different experimental parameters is achieved. The latter is important for a quantitative evaluation of CARS images.
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Affiliation(s)
- Nadine Vogler
- Institute of Photonic Technology Jena, Albert-Einstein-Strasse 9, D-07745 Jena, Germany
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