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Ruehl H, Guenther T, Zimmermann A. Direct Processing of PVD Hard Coatings via Focused Ion Beam Milling for Microinjection Molding. MICROMACHINES 2023; 14:294. [PMID: 36837994 PMCID: PMC9961046 DOI: 10.3390/mi14020294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Revised: 01/18/2023] [Accepted: 01/21/2023] [Indexed: 06/18/2023]
Abstract
Hard coatings can be applied onto microstructured molds to influence wear, form filling and demolding behaviors in microinjection molding. As an alternative to this conventional manufacturing procedure, "direct processing" of physical-vapor-deposited (PVD) hard coatings was investigated in this study, by fabricating submicron features directly into the coatings for a subsequent replication via molding. Different diamondlike carbon (DLC) and chromium nitride (CrN) PVD coatings were investigated regarding their suitability for focused ion beam (FIB) milling and microinjection molding using microscope imaging and areal roughness measurements. Each coating type was deposited onto high-gloss polished mold inserts. A specific test pattern containing different submicron features was then FIB-milled into the coatings using varied FIB parameters. The milling results were found to be influenced by the coating morphology and grain microstructure. Using injection-compression molding, the submicron structures were molded onto polycarbonate (PC) and cyclic olefin polymer (COP). The molding results revealed contrasting molding performances for the studied coatings and polymers. For CrN and PC, a sufficient replication fidelity based on AFM measurements was achieved. In contrast, only an insufficient molding result could be obtained for the DLC. No abrasive wear or coating delamination could be found after molding.
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Affiliation(s)
- Holger Ruehl
- Institute for Micro Integration (IFM), Faculty 7—Engineering Design, Production Engineering and Automotive Engineering, University of Stuttgart, Allmandring 9b, 70569 Stuttgart, Germany
| | - Thomas Guenther
- Institute for Micro Integration (IFM), Faculty 7—Engineering Design, Production Engineering and Automotive Engineering, University of Stuttgart, Allmandring 9b, 70569 Stuttgart, Germany
| | - André Zimmermann
- Institute for Micro Integration (IFM), Faculty 7—Engineering Design, Production Engineering and Automotive Engineering, University of Stuttgart, Allmandring 9b, 70569 Stuttgart, Germany
- Hahn-Schickard, Allmandring 9b, 70569 Stuttgart, Germany
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Chen D, Wang Y, Zhou H, Huang Z, Zhang Y, Guo CF, Zhou H. Current and Future Trends for Polymer Micro/Nanoprocessing in Industrial Applications. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022; 34:e2200903. [PMID: 35313049 DOI: 10.1002/adma.202200903] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 03/16/2022] [Indexed: 06/14/2023]
Abstract
Polymers are widely used in optical devices, electronic devices, energy-harvesting/storage devices, and sensors, owing to their low weight, excellent flexibility, and simple fabrication process. With advancements in micro/nanoprocessing techniques and more demanding application requirements, it is becoming necessary to realize high-resolution fabrication of polymers to prepare miniaturized devices. This is particularly because conventional processing technologies suffer from high thermal stress and strong adhesion/friction, which can irreversibly damage the micro/nanostructures of miniaturized devices. In addition, although the use of advanced fabrication methods to prepare high-resolution micro/nanostructures is explored, these methods are limited to laboratory research or small-batch production. This review focuses on the micro/nanoprocessing of polymeric materials and devices with high spatial precision and replication accuracy for industrial applications. Specifically, the current state-of-the-art techniques and future trends for micro/nanomolding, high-energy beam processing, and micro/nanomachining are discussed. Moreover, an overview of the fabrication and applications of various polymer-based elements and devices such as microlenses, biosensors, and transistors is provided. These techniques are expected to be widely applied for multiscale and multimaterial processing as well as for multifunction integration in next-generation integrated devices, such as photoelectric, smart, and biodegradable devices.
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Affiliation(s)
- Dan Chen
- School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Yunming Wang
- School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Helezi Zhou
- School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Zhigao Huang
- School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Yun Zhang
- School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Chuan Fei Guo
- Department of Materials Science and Engineering, Southern University of Science and Technology, Shenzhen, Guangdong, 518055, China
| | - Huamin Zhou
- School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan, 430074, China
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Jiang W, Zhao W, Zhou T, Wang L, Qiu T. A Review on Manufacturing and Post-Processing Technology of Vascular Stents. MICROMACHINES 2022; 13:mi13010140. [PMID: 35056305 PMCID: PMC8778070 DOI: 10.3390/mi13010140] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Revised: 01/13/2022] [Accepted: 01/14/2022] [Indexed: 02/04/2023]
Abstract
Percutaneous coronary intervention (PCI) with stent implantation is one of the most effective treatments for cardiovascular diseases (CVDs). However, there are still many complications after stent implantation. As a medical device with a complex structure and small size, the manufacture and post-processing technology greatly impact the mechanical and medical performances of stents. In this paper, the development history, material, manufacturing method, and post-processing technology of vascular stents are introduced. In particular, this paper focuses on the existing manufacturing technology and post-processing technology of vascular stents and the impact of these technologies on stent performance is described and discussed. Moreover, the future development of vascular stent manufacturing technology will be prospected and proposed.
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Affiliation(s)
- Wei Jiang
- School of Mechanical Engineering, Beijing Institute of Technology, No. 5 Zhongguancun South Street, Haidian District, Beijing 100081, China; (W.J.); (L.W.)
| | - Wenxiang Zhao
- Key Laboratory of Fundamental Science for Advanced Machining, Beijing Institute of Technology, No. 5 Zhongguancun South Street, Haidian District, Beijing 100081, China; (W.Z.); (T.Z.)
| | - Tianfeng Zhou
- Key Laboratory of Fundamental Science for Advanced Machining, Beijing Institute of Technology, No. 5 Zhongguancun South Street, Haidian District, Beijing 100081, China; (W.Z.); (T.Z.)
| | - Liang Wang
- School of Mechanical Engineering, Beijing Institute of Technology, No. 5 Zhongguancun South Street, Haidian District, Beijing 100081, China; (W.J.); (L.W.)
| | - Tianyang Qiu
- Key Laboratory of Fundamental Science for Advanced Machining, Beijing Institute of Technology, No. 5 Zhongguancun South Street, Haidian District, Beijing 100081, China; (W.Z.); (T.Z.)
- Correspondence:
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Tuning Power Ultrasound for Enhanced Performance of Thermoplastic Micro-Injection Molding: Principles, Methods, and Performances. Polymers (Basel) 2021; 13:polym13172877. [PMID: 34502917 PMCID: PMC8433713 DOI: 10.3390/polym13172877] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Revised: 08/20/2021] [Accepted: 08/21/2021] [Indexed: 11/17/2022] Open
Abstract
With the wide application of Micro-Electro-Mechanical Systems (MEMSs), especially the rapid development of wearable flexible electronics technology, the efficient production of micro-parts with thermoplastic polymers will be the core technology of the harvesting market. However, it is significantly restrained by the limitations of the traditional micro-injection-molding (MIM) process, such as replication fidelity, material utilization, and energy consumption. Currently, the increasing investigation has been focused on the ultrasonic-assisted micro-injection molding (UAMIM) and ultrasonic plasticization micro-injection molding (UPMIM), which has the advantages of new plasticization principle, high replication fidelity, and cost-effectiveness. The aim of this review is to present the latest research activities on the action mechanism of power ultrasound in various polymer micro-molding processes. At the beginning of this review, the physical changes, chemical changes, and morphological evolution mechanism of various thermoplastic polymers under different application modes of ultrasonic energy field are introduced. Subsequently, the process principles, characteristics, and latest developments of UAMIM and UPMIM are scientifically summarized. Particularly, some representative performance advantages of different polymers based on ultrasonic plasticization are further exemplified with a deeper understanding of polymer–MIM relationships. Finally, the challenges and opportunities of power ultrasound in MIM are prospected, such as the mechanism understanding and commercial application.
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Baek S, Kim K, Sung Y, Jung P, Ju S, Kim W, Kim SJ, Hong SH, Lee H. Solution-processable multi-color printing using UV nanoimprint lithography. NANOTECHNOLOGY 2020; 31:125301. [PMID: 31783377 DOI: 10.1088/1361-6528/ab5d42] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Recently, coloring based on nanostructure-light interaction has attracted much attention, because it has many advantages over pigment-based conventional coloring in terms of being non-toxic and highly durable in the environment, and providing high resolution. The asymmetric Fabry-Perot (FP) cavity absorber is the most manufacturable structure among coloring structures because it is simply produced and easily tunable. However, it cannot be applied practically because of the lack of a manufacturing technique that enables simultaneous fabrication of multi-color structures with different heights. Here, the fabrication of colored reflective characters based on various asymmetric FP absorbers with micrometer-scale pixel size are reported. Various cavities with different thicknesses are fabricated in a single step using UV imprint lithography and a simple deposition process. UV/visible spectroscopy is used to characterize the fabricated FP resonator. This absorber demonstrates high absorption, close to 90%, resulting in vivid colors with high resolution of 12700 DPI. It can be potentially used in reflective color displays field, functionalized color decorations, and security color patterns area. It is believed that this study would open up new possibilities for high density color printing in practical industry by introducing cost effective nanoimprint lithography technology.
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Affiliation(s)
- Seungho Baek
- Department of Material Science and Engineering, Korea University, Seoul 02841, Republic of Korea
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Roth B, Zhou MY, Drummer D. Influence of the Mold Temperature and Part Thickness on the Replication Quality and Molecular Orientation in Compression Injection Molding of Polystyrene. INT POLYM PROC 2019. [DOI: 10.3139/217.3802] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Abstract
It is well known that the process of injection molding with dynamic mold temperature control leads to a good replication quality of high aspect ratio microstructures. However, the inhomogeneous pressure distribution during the holding pressure phase results in an anisotropy of the component properties, low dimensional accuracy and, especially with optical polymers, in undesired stress birefringence. The anisotropy is based on the orientation of the molecular chains in the flow direction, which can be reduced by an injection-compression molding (ICM) process. In order to use the synergy from both processes, an injection-compression molding process with dynamic mold temperature control can be utilized. Within the scope of this investigation, the new process was reproduced by an ICM process at elevated mold temperature (ICM_EMT) and compared with injection molding (IM) with regard to molding accuracy and optical properties in dependence of component thickness and mold temperature. In order to evaluate the molding accuracy, the roughness of a wire-eroded microstructure on the cavity surface was measured. To determine the degree of orientation, the optical properties considered were the transmission and the path difference. It was shown that the adapted ICM process was able to achieve a high degree of replication accuracy with a low degree of orientation, especially for thin-walled components. ICM at elevated mold temperature reduced the path difference in the components with the lowest wall thickness by a factor of two while at the same time optimizing the replication of the microstructure. This could also be confirmed by transmission measurements.
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Affiliation(s)
- B. Roth
- Institute of Polymer Technology , Friedrich-Alexander-Universität Erlangen-Nuremberg, Erlangen , Germany
| | - M.-Y. Zhou
- Institute of Polymer Technology , Friedrich-Alexander-Universität Erlangen-Nuremberg, Erlangen , Germany
| | - D. Drummer
- Institute of Polymer Technology , Friedrich-Alexander-Universität Erlangen-Nuremberg, Erlangen , Germany
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