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1
Ghaznavi, Amirreza, Jie Xu, and Seth A. Hara. "A Non-Sacrificial 3D Printing Process for Fabricating Integrated Micro/Mesoscale Molds." Micromachines 14, no. 7 (June 30, 2023): 1363. http://dx.doi.org/10.3390/mi14071363.
Анотація:
Three-dimensional printing technology has been implemented in microfluidic mold fabrication due to its freedom of design, speed, and low-cost fabrication. To facilitate mold fabrication processes and avoid the complexities of the soft lithography technique, we offer a non-sacrificial approach to fabricate microscale features along with mesoscale features using Stereolithography (SLA) printers to assemble a modular microfluidic mold. This helps with addressing an existing limitation with fabricating complex and time-consuming micro/mesoscale devices. The process flow, optimization of print time and feature resolution, alignments of modular devices, and the advantages and limitations with the offered technique are discussed in this paper.
2
Bley, P. "The Liga Process for Fabrication of Three-Dimensional Microscale Structures." Interdisciplinary Science Reviews 18, no. 3 (September 1993): 267–72. http://dx.doi.org/10.1179/isr.1993.18.3.267.
3
Sugimoto, Ryota, Ju Hun Lee, Ju-Hyuck Lee, Hyo-Eon Jin, So Young Yoo, and Seung-Wuk Lee. "Bacteriophage nanofiber fabrication using near field electrospinning." RSC Advances 9, no. 67 (2019): 39111–18. http://dx.doi.org/10.1039/c9ra07510k.
Анотація:
Using liquid crystalline suspension of the phage, we successfully fabricated nano- and microscale pure phage fibers. Through a near field electrospinning process, we fabricated the desired phage fiber pattern with tunable direction and spacing.
4
Kim, Kangil, Jae Keun Lee, Seung Ju Han, and Sangmin Lee. "A Novel Top-Down Fabrication Process for Vertically-Stacked Silicon-Nanowire Array." Applied Sciences 10, no. 3 (February 8, 2020): 1146. http://dx.doi.org/10.3390/app10031146.
Анотація:
Silicon nanowires are widely used for sensing applications due to their outstanding mechanical, electrical, and optical properties. However, one of the major challenges involves introducing silicon-nanowire arrays to a specific layout location with reproducible and controllable dimensions. Indeed, for integration with microscale structures and circuits, a monolithic wafer-level process based on a top-down silicon-nanowire array fabrication method is essential. For sensors in various electromechanical and photoelectric applications, the need for silicon nanowires (as a functional building block) is increasing, and thus monolithic integration is highly required. In this paper, a novel top-down method for fabricating vertically-stacked silicon-nanowire arrays is presented. This method enables the fabrication of lateral silicon-nanowire arrays in a vertical direction, as well as the fabrication of an increased number of silicon nanowires on a finite dimension. The proposed fabrication method uses a number of processes: photolithography, deep reactive-ion etching, and wet oxidation. In applying the proposed method, a vertically-aligned silicon-nanowire array, in which a single layer consists of three vertical layers with 20 silicon nanowires, is fabricated and analyzed. The diamond-shaped cross-sectional dimension of a single silicon nanowire is approximately 300 nm in width and 20 μm in length. The developed method is expected to result in highly-sensitive, reproducible, and low-cost silicon-nanowire sensors for various biomedical applications.
5
Bunea, Ada-Ioana, Nuria del Castillo Iniesta, Ariadni Droumpali, Alexandre Emmanuel Wetzel, Einstom Engay, and Rafael Taboryski. "Micro 3D Printing by Two-Photon Polymerization: Configurations and Parameters for the Nanoscribe System." Micro 1, no. 2 (September 25, 2021): 164–80. http://dx.doi.org/10.3390/micro1020013.
Анотація:
3D printing by two-photon polymerization enables the fabrication of microstructures with complex shapes and critical dimensions of a few hundreds of nanometers. On state-of-the art commercial two-photon polymerization systems, an immense 3D design freedom can be put into practice by direct laser writing using a precise fabrication technology, which makes this approach highly attractive for different applications on the microscale, such as microrobotics, micro-optics, or biosensing. However, navigating the different possible configurations and selecting the optimal parameters for the fabrication process often requires intensive testing and optimization. In addition to the more established acrylate-based resins, there is a growing interest in the use of soft materials. In this paper, we demonstrate the fabrication of various microscale structures by two-photon polymerization using a Nanoscribe Photonic Professional GT+ commercial system. Furthermore, we describe the different configurations of the system and parameter selection, as well as commercial resins and their chemical and mechanical properties. Finally, we provide a short guide aiming to serve as starting point for the two-photon polymerization-based fabrication of various microscale architectures with distinct characteristics.
6
Choi, Jinwoong, Myeonghyeon Cho, and Bumjoo Kim. "Fabrication of Nonconductive Microscale Patterns on Ion Exchange Membrane by Laser Process." Korean Journal of Materials Research 33, no. 2 (February 27, 2023): 71–76. http://dx.doi.org/10.3740/mrsk.2023.33.2.71.
7
Yang, Zhuo Qing, Hong Wang, Zheng Jie Zhang, Gui Fu Ding, Xiao Lin Zhao, and Chun Yan Jiang. "Fabrication and Mechanical Characterization of a Microscale Electrophoretic Polymer Based on MEMS Technology." Advanced Materials Research 422 (December 2011): 375–78. http://dx.doi.org/10.4028/www.scientific.net/amr.422.375.
Анотація:
Microscale polyurethane modified epoxy resin film has been fabricated using MEMS tehnologies in the present paper. The effect of different process conditions on the thickness of fabricated film was discussed. The microscale film shows smooth and uniform surface morphology. The tensile test of the film by DMA indicates its tensile strength and Young's modulus are approximately 55MPa and 1.8GPa, respectively. The fracture section of the film was characterized by SEM. In addition, the interface bonding strength of the fabricated film between Ni substrate is much higher than Parylene-C and SU-8. This microscale polymer film is promising in several smart MEMS fields, especially bio-MEMS structures.
8
Tang, Min Jin, Hui Min Xie, Jian Guo Zhu, Peng Wan Chen, Qing Ming Zhang, and Xiao Jun Li. "A New Moiré Grating Fabrication Technique Using Hot Embossing Lithography." Applied Mechanics and Materials 83 (July 2011): 7–12. http://dx.doi.org/10.4028/www.scientific.net/amm.83.7.
Анотація:
Moiré grating is a basic optical component, and can be used in various moiré methods. The conventional grating fabrication technology is based on photolithography and holographic interferometry, however, it requires complex optical components and is very difficult to put into practice. In this study, nanoimprint lithography (NIL), or rather, hot embossing lithography (HEL), is proposed for producing high frequency grating. Compared with silicon mold, holographic moiré grating mold costs less and is not easy to break, thus is chosen to be the mold in HEL. Using this mold and the hot embossing system, the grating structure can be transferred to the polymer after HEL process. Through a number of experiments, the process parameters were optimized and gratings were successfully fabricated. The multi-scale morphology of the fabricated gratings was then characterized by scanning electron microscope (SEM), atomic force microscope (AFM) and moiré interferometry. The microscale images observed by AFM and SEM show the regulate dots with equal spacing and the macroscale moiré patterns illuminate the excellent qualities of fabricated grating in a large area. The successful experimental results demonstrate the feasibility of the grating fabricated by HEL for the moiré measurement.
9
Herrera-Loya, Maite R., L. Mariana Cervantes-Herrera, Sofia Gutierrez-Vallejo, and Jorge G. Ibanez. "Leaded or unleaded? Homemade microscale tin electroplating." Chemistry Teacher International 4, no. 1 (March 1, 2022): 97–102. http://dx.doi.org/10.1515/cti-2021-0024.
Анотація:
Abstract Social distancing measures due to the SARS-CoV-2 virus have profoundly challenged the educational experimental work. We have sought to remediate this issue by designing a series of low cost, low risk, quick, and qualitative electrochemistry and corrosion experiments to be performed in the student’s homes at the microscale with a kit provided by the teacher. One such experience is the electroplating of Sn from an aqueous chloride solution using readily available soldering wires (e.g., Sn–Pb alloy, or Sn–Ag–Cu alloy). This process catches students’ attention due to its simplicity and variety of possible applications that include corrosion protection, fabrication of electronic components, plating of cooking utensils, lithium batteries, etc.
10
Park, Seorin, Da Young Lee, and Sunghun Cho. "Development of Light-Scribing Process Using L-Ascorbic Acid for Graphene Micro-Supercapacitor." Micromachines 15, no. 7 (June 30, 2024): 858. http://dx.doi.org/10.3390/mi15070858.
Анотація:
The rapid development of smart technologies is accelerating the growing demand for microscale energy storage devices. This work reports a facile and practical approach to fabricating interdigitated graphene micro-patterns through the LSC process accompanied by the l-ascorbic acid (L-AA) and preheating treatment. Our work offered a higher degree of GO reduction than the conventional microfabrication. It significantly shortened the overall processing time to obtain the micro-patterns with improved electrical and electrochemical performances. The interdigitated MSC composed of 16 electrodes exhibited a high capacitance of 14.1 F/cm3, energy density of 1.78 mWh/cm3, and power density of 69.9 mW/cm3. Furthermore, the fabricated MSC device demonstrated excellent cycling stability of 88.2% after 10,000 GCD cycles and a high rate capability of 81.1% at a current density of 1.00 A/cm3. The fabrication process provides an effective means for producing high-performance MSCs for miniaturized electronic devices.
11
Kadekar, Vinay, Weiya Fang, and Frank Liou. "Deposition Technologies For Micromanufacturing: A Review." Journal of Manufacturing Science and Engineering 126, no. 4 (November 1, 2004): 787–95. http://dx.doi.org/10.1115/1.1811118.
Анотація:
This paper discusses the microdeposition technologies used in the fabrication of meso- and microscale structures. The ability to process a wide range of materials and the flexibility to build functional and geometrically complex structures in meso- and microscale gives the microdeposition method some advantages over micromachining or lithography methods investigated extensively in the past. In this paper, work on deposition technology is reviewed, including material, supply of material, powder flow rate, and manipulation of particles and microdeposition technologies. The advantages and disadvantages of each technology are summarized at the end of the paper.
12
Wang, Dazhi, Kuipeng Zhao, Yuheng Yuan, Zhu Wang, Haoran Zong, Xi Zhang, and Junsheng Liang. "Fabrication and Characterization of a Microscale Piezoelectric Vibrator Based on Electrohydrodynamic Jet Printed PZT Thick Film." Micromachines 12, no. 5 (May 6, 2021): 524. http://dx.doi.org/10.3390/mi12050524.
Анотація:
This paper proposes a novel way of preparing a PZT thick film micro vibrator using the electrohydrodynamic jet (E-Jet) printing technique. Initially, a micro piezoelectric vibrator was simulated and designed for obtaining optimized structure, which has a total thickness of less than 600 µm. Subsequently, the PZT thick film element was directly printed on the elastic body using the E-Jet printing. This method avoids the glue fabrication process involved in the bulk piezoelectric fabrication, thus avoiding the limits of voltage drops, isolating and absorbing amplitude usually occurred in the vibrator having glue interface. It was observed that B02 and B03 modes were generated at frequencies of 29.74 and 79.14 kHz, respectively, and the amplitudes of B02 and B03 modes were 406 and 176 nm, respectively. The error between the simulation and test result in the B03 modal is only 0.35%, which indicates the accuracy of the simulation analysis and the fabrication process. The PZT thick film traveling-wave micro vibrator successfully realized bidirectional rotation of a rotor, with a maximum speed of 681 rpm, which also shows a linear relationship between excitation voltage and rotary speed. This paper provides an effective method for preparing a micro piezoelectric vibrator for MEMS ultrasonic devices, which simplifies the manufacturing process and enhances the performance of the piezoelectric vibrator.
13
Yang, Jung Ho, Zhi Jun Zhao, and Sang Hu Park. "Fabrication of Microscale Wrinkles on a Curved Surface Using Weak-Polymerization and Thermal Curing Process." Journal of the Korean Society for Precision Engineering 33, no. 10 (October 1, 2016): 875–80. http://dx.doi.org/10.7736/kspe.2016.33.10.875.
14
Chen, M., X. Ding, L. Que, and X. Liang. "Fabrication of microstructures on curved hydrogel substrates." Journal of Vacuum Science & Technology B 40, no. 5 (September 2022): 052804. http://dx.doi.org/10.1116/6.0002071.
Анотація:
Emerging wearable devices are very attractive and promising in biomedical and healthcare fields because of their biocompatibility for monitoring in situ biomarker-associated signals and external stimulus. Many such devices or systems demand microscale sensors fabricated on curved and flexible hydrogel substrates. However, fabrication of microstructures on such substrates is still challenging because the traditional planar lithography process is not compatible with curved, flexible, and hydrated substrates. Here, we present a shadow-mask-assisted deposition process capable of directly generating metallic microstructures on the curved hydrogel substrate, specifically the contact lens, one of the most popular hydrogel substrates for wearable biomedical applications. In this process, the curved hydrogel substrate is temporarily flattened on a planar surface and metal features are deposited on this substrate through a shadow mask. To achieve a high patterning fidelity, we have experimentally and theoretically investigated various types of distortion due to wrinkles on 3D-printed sample holders, geometric distortion of the substrate due to the flattening process, and volume change of the hydrogel material during the dehydration and hydration processes of the contact lens. Using this method, we have demonstrated fabrication of various titanium pattern arrays on contact lenses with high fidelity and yield.
15
Zhang, Bing, Shikang Li, M. Shafin H. Qureshi, Ukil Mia, Zhenghui Ge, and Aiping Song. "In-Situ Assembly of MoS2 Nanostructures on EHD-Printed Microscale PVDF Fibrous Films for Potential Energy Storage Applications." Polymers 14, no. 23 (December 1, 2022): 5250. http://dx.doi.org/10.3390/polym14235250.
Анотація:
Three-dimensional (3D) printing has been widely utilized to fabricate free-standing electrodes in energy-related fields. In terms of fabrication, the two most challenging limitations of 3D printed electrodes are the poor printing resolution and simple structural dimension. Here we proposed a novel process to fabricate molybdenum disulfide-polyvinylidene fluoride (MoS2-PVDF) hierarchical electrodes for energy storage applications. The 20-layer microscale PVDF films with a stable fiber width of 8.3 ± 1.2 μm were fabricated by using electrohydrodynamic (EHD) printing. MoS2 nanostructures were synthesized and assembled on the microscale PVDF fibers by using hydrothermal crystal growth. The structural and material investigations were conducted to demonstrate the geometrical morphology and materials component of the composite structure. The electrochemical measurements indicated that the MoS2-PVDF electrodes exhibited the typical charge-discharge performance with a mass specific capacitance of 60.2 ± 4.5 F/g. The proposed method offers a facile and scalable approach for the fabrication of high-resolution electrodes, which might be further developed with enhanced specific capacitance in energy storage fields.
16
Oliveira, Cristiana, José A. Teixeira, Nelson Oliveira, Sónia Ferreira, and Cláudia M. Botelho. "Microneedles’ Device: Design, Fabrication, and Applications." Macromol 4, no. 2 (May 15, 2024): 320–55. http://dx.doi.org/10.3390/macromol4020019.
Анотація:
The delivery of therapeutical molecules through the skin, particularly to its deeper layers, is impaired due to the stratum corneum layer, which acts as a barrier to foreign substances. Thus, for the past years, scientists have focused on the development of more efficient methods to deliver molecules to skin distinct layers. Microneedles, as a new class of biomedical devices, consist of an array of microscale needles. This particular biomedical device has been drawing attention due to its ability to breach the stratum corneum, forming micro-conduits to facilitate the passage of therapeutical molecules. The microneedle device has several advantages over conventional methods, such as better medication adherence, easiness, and painless self-administration. Moreover, it is possible to deliver the molecules swiftly or over time. Microneedles can vary in shape, size, and composition. The design process of a microneedle device must take into account several factors, like the location delivery, the material, and the manufacturing process. Microneedles have been used in a large number of fields from drug and vaccine application to cosmetics, therapy, diagnoses, tissue engineering, sample extraction, cancer research, and wound healing, among others.
17
Horade, M., K. Yamada, T. Yamawaki, and M. Yashima. "Research on fabrication method for floating structures using general photolithography with high versatility." Journal of Micromechanics and Microengineering 31, no. 12 (October 25, 2021): 125004. http://dx.doi.org/10.1088/1361-6439/ac2d9b.
Анотація:
Abstract This research reports a micro-fabrication method for plastic microscale structures. Although a stepped shape, such as a cantilever, can be fabricated by micro electro mechanical systems (MEMS) deep etching technology, its disadvantages include the complicated fabrication process and its limited utilization with silicon only. Therefore, in this study, with an aim to address the aforementioned problems, we have realized the fabrication of a multi-stage structure using just a general photolithography process with high versatility. Specifically, it can be manufactured using only SU-8 resist and AZ resist, which are often used in the MEMS process. The AZ resist has the advantage of dissolving in the developer of the SU-8 resist, whether exposed or non-exposed. Thus, the sacrificial layer of AZ resist can be implemented with the SU-8 developer, thereby eliminating the need for dangerous chemicals such as hydrofluoric acid, which is used to etch silicon oxide. Herein, we have derived the optimum conditions by considering in advance the thickness of the AZ resist, the time taken to be etched in SU-8, and the desired features. Based on these optimum processing conditions, the structure could be suspended only in the region where the hole array was patterned. Although methods of using AZ resist as a sacrificial layer and floating SU-8 have been reported, in this study, both floating and fixed structures could be simultaneously fabricated by photolithography only. Accordingly, we successfully manufactured a gear structure and a MEMS sensor, both of which have floating and fixed structures. The above structures are made of highly transparent SU-8 on a glass substrate; hence, they are easily observable with a microscope. The reason for the widespread use of polydimethylsiloxane micro-channels is that they are transparent materials that can be observed under a microscope and fabricated by simple photolithography of the SU-8 resist, enabling non-microfabrication specialists to enter this field. These findings have the potential to form the foundation for developing new biochemical tests, such as actuators and sensors driven under a microscope.
18
Sharma, Vyom, and C. Chandraprakash. "Quasi-superhydrophobic microscale two-dimensional phononic crystals of stainless steel 304." Journal of Applied Physics 131, no. 18 (May 14, 2022): 184901. http://dx.doi.org/10.1063/5.0079375.
Анотація:
Fabrication of metallic phononic and photonic crystals of characteristic size between 10 and [Formula: see text]m remains a challenge in precision using the conventional machining processes or too tedious for the cleanroom-based processes. We report the fabrication and elastodynamic bandgaps of two-dimensional phononic crystals (PhCs) machined on stainless steel 304 (SS304) substrates using the wire-electrochemical micromachining (wire-ECMM) process. Square arrays of pillars of length [Formula: see text]m and cross section either [Formula: see text] or [Formula: see text] with periods 650 and [Formula: see text]m, respectively, were micromachined on an SS304 homogeneous substrate. Based on these arrays, three types of PhCs were considered: air-SS304, water-SS304, and epoxy-SS304, where air, water, and epoxy are the hosts and SS304 pillars are the scatterers. We found that texturing the surface increased the contact angle of a [Formula: see text]-[Formula: see text]l-water-droplet from [Formula: see text] for an untextured SS304 substrate to a maximum of [Formula: see text] for SS304 PhCs, making the latter quasi-superhydrophobic. Dispersion relations evaluated using the finite-element method revealed the presence of partial bandgaps in the 0.1–2.7 MHz for all PhCs and a complete bandgap for the epoxy-SS304 PhCs. Transmittance spectrums for incident plane waves also provided evidence for the occurrence of bandgaps. Furthermore, the buckling analysis indicated that these pillars do not undergo buckling until yield—making them mechanically robust.
19
Liu, Xin, Stephan Prinz, Heino Besser, Wilhelm Pfleging, Markus Wissmann, Christoph Vannahme, Markus Guttmann, et al. "Organic semiconductor distributed feedback laser pixels for lab-on-a-chip applications fabricated by laser-assisted replication." Faraday Discuss. 174 (2014): 153–64. http://dx.doi.org/10.1039/c4fd00077c.
Анотація:
The integration of organic semiconductor distributed feedback (DFB) laser sources into all-polymer chips is promising for biomedical or chemical analysis. However, the fabrication of DFB corrugations is often expensive and time-consuming. Here, we apply the method of laser-assisted replication using a near-infrared diode laser beam to efficiently fabricate inexpensive poly(methyl methacrylate) (PMMA) chips with spatially localized organic DFB laser pixels. This time-saving fabrication process enables a pre-defined positioning of nanoscale corrugations on the chip and a simultaneous generation of nanoscale gratings for organic edge-emitting laser pixels next to microscale waveguide structures. A single chip of size 30 mm × 30 mm can be processed within 5 min. Laser-assisted replication allows for the subsequent addition of further nanostructures without a negative impact on the existing photonic components. The minimum replication area can be defined as being as small as the diode laser beam focus spot size. To complete the fabrication process, we encapsulate the chip in PMMA using laser transmission welding.
20
Herrera-Granados, German, Kiwamu Ashida, Ichiro Ogura, Yuichi Okazaki, Noboru Morita, Hirofumi Hidai, Souta Matsusaka, and Akira Chiba. "Development of a Non-RigidMicro-Scale Cutting Mechanism Measuring the Cutting Force Using an Optical Lever." International Journal of Automation Technology 8, no. 6 (November 5, 2014): 903–11. http://dx.doi.org/10.20965/ijat.2014.p0903.
Анотація:
A new cutting mechanism for the fabrication of microscale grooves is presented in this study. Based on the control principle of the nano-cutting mechanism using an Atomic Force Microscope (AFM), in the newly developed system, a single crystal diamond tool is mounted at the free edge of a cantilever beam and is used for the removal of material. During the cutting process, the cantilever undergoes a deformation that is required for the implementation of a machining force feedback control. It was experimentally observed that the use of this mechanism enables to maintain the cutting depth of the micro-grooves constant even if they are fabricated on inclined surfaces; this is achieved by maintaining the normal cutting force constant using a feedback controller. For this experimental system, an optical lever is used to measure the angular deformation at the tip of the cantilever, thus providing a better understanding of total cutting force involved in the machining process.
21
Li, Jing Feng, Song Zhe Jin, and Yong Li. "Fabrication of Si3N4 Micro-Components by a Combined Microfabrication Process." Key Engineering Materials 287 (June 2005): 28–32. http://dx.doi.org/10.4028/www.scientific.net/kem.287.28.
Анотація:
Si-based high-temperature ceramics are attractive materials for power microelectromechanical systems (power MEMS), such as microscale gas turbines, micro-combustors and micro-reactors. This presentation introduces a novel process for the microfabrication of Si3N4 ceramics, which mainly consists of pre-sintering of Si powder compacts, micromachining of pre-sintered Si preforms and reaction sintering of the micromachined Si preforms. The present process has its high potential for Si3N4 3-dimensional microfabrication because it combines the machinablity of pre-sintered Si powder compacts and near-net shaping characteristic of S3N4 reaction sintering. Si3N4 micro-components such as micro nozzle arrays and micro-rotor were fabricated by using the present process.
22
Jung, Jaehan. "Continuous manufacturing of 3D patterned hybrid film via a roll-to-roll process with UV curing." Modern Physics Letters B 34, no. 07n09 (March 16, 2020): 2040039. http://dx.doi.org/10.1142/s0217984920400394.
Анотація:
A strategy for continuous fabrication of a microscale 3D-patterned hybrid composite film composed of alumina and acrylate resin was developed using roll-to-roll production. Conventional thermal curing was replaced with a UV curing procedure to facilitate rapid and economical processing. A seamless engraved soft urethane mold was first produced using a patterned metal roll. Subsequently, alumina and acrylate resin were cured on the engraved mold via UV irradiation to produce patterned hybrid films. The dispersion of alumina particles in acylate resin was enhanced by utilizing amine acrylate. Photopolymerization was measured using Fourier-transform infrared spectroscopy. The morphology of the soft engraved mold and the patterned hybrid film was investigated using scanning electron microscopy.
23
Chen, Jianqiu, Liao Gan, Zhipeng Pan, Honglong Ning, Zhiqiang Fang, Hongfu Liang, Ruiqiang Tao, Wei Cai, Rihui Yao, and Junbiao Peng. "A Strategy toward Realizing Ultrashort Channels and Microstructures Array by Piezoelectric Inkjet Printing." Nanomaterials 9, no. 11 (October 24, 2019): 1515. http://dx.doi.org/10.3390/nano9111515.
Анотація:
Inkjet printing has been proved to be a powerful tool in the cost-effective ambient deposition of functional materials for the fabrication of electronic devices in the past decades. However, restricted by equipment and inks, the feature size of printed dots or lines with conventional inkjet printing is usually limited to several tens of micrometers, which could not fit the requirements for the fabrication of large-area, high-resolution microscale, even nanoscale, structures. Therefore, various technical means were developed for breaking the equipment limits. Here, we report a strategy for realizing ultrashort channels and homogeneous microstructures arrays by a conventional piezoelectric inkjet printing technique without any additional pre-mask process on the substrate. This strategy extends application of piezoelectric inkjet printing technique to biological and technological areas.
24
Boonhaijaroen, Narit, Pitchaya Sitthi-amorn, Werayut Srituravanich, Kwanrat Suanpong, Sanong Ekgasit, and Somchai Pengprecha. "Alignment Control of Ferrite-Decorated Nanocarbon Material for 3D Printing." Micromachines 15, no. 6 (June 6, 2024): 763. http://dx.doi.org/10.3390/mi15060763.
Анотація:
This paper demonstrates the potential of anisotropic 3D printing for alignable carbon nanomaterials. The ferrite-decorated nanocarbon material was synthesized via a sodium solvation process using epichlorohydrin as the coupling agent. Employing a one-pot synthesis approach, the novel material was incorporated into a 3D photopolymer, manipulated, and printed using a low-cost microscale 3D printer, equipped with digital micromirror lithography, monitoring optics, and magnetic actuators. This technique highlights the ability to control the microstructure of 3D-printed objects with sub-micron precision for applications such as microelectrode sensors and microrobot fabrication.
25
Liu, Wendong, Xiaojing Wang, Siyuan Xiang, Yuechang Lian, and Shengyang Tao. "Stretchable Superhydrophobic Surfaces: From Basic Fabrication Strategies to Applications." Processes 12, no. 1 (January 3, 2024): 124. http://dx.doi.org/10.3390/pr12010124.
Анотація:
Superhydrophobic surfaces find extensive applications in various fields, including self-cleaning, liquid manipulation, anti-icing, and water harvesting. To achieve superhydrophobicity, the surfaces are designed with hierarchical nano- and/or microscale protrusions. These structures result in a static contact angle above 150° and a sliding/rolling-off angle below 10° when water droplets deposit on the surface. The combination of hierarchical structures and low-surface energy materials contributes to this unique liquid-repellent property. In addition to liquid repellency, the durability of these surfaces is crucial for practical applications, which has prompted the exploration of stretchable superhydrophobic surfaces as a viable solution. The flexibility of these surfaces means that they are effectively safeguarded against mechanical damage and can withstand daily wear and tear. Over the last decade, considerable research has been dedicated to developing stretchable superhydrophobic surfaces to expand their potential applications. This review provides an overview of stretchable superhydrophobic surfaces, specifically emphasizing current processing strategies and their prospective applications. Additionally, we present a forward-looking perspective on future fabrication methods to create robust superhydrophobic surfaces, further enhancing their practicality and versatility.
26
Mohammed, Muneer, Usama Umer, Ateekh Rehman, Abdulrahman Al-Ahmari, and Abdulaziz El-Tamimi. "Microchannels Fabrication in Alumina Ceramic Using Direct Nd:YAG Laser Writing." Micromachines 9, no. 8 (July 27, 2018): 371. http://dx.doi.org/10.3390/mi9080371.
Анотація:
Ceramic microchannels have important applications in different microscale systems like microreactors, microfluidic devices and microchemical systems. However, ceramics are considered difficult to manufacture owing to their wear and heat resistance capabilities. In this study, microchannels are developed in alumina ceramic using direct Nd:YAG laser writing. The laser beam with a characteristic pulse width of 10 µs and a beam spot diameter of 30 µm is used to make 200 µm width microchannels with different depths. The effects of laser beam intensity and pulse overlaps on dimensional accuracy and material removal rate have been investigated using different scanning patterns. It is found that beam intensity has a major influence on dimensional accuracy and material removal rate. Optimum parameter settings are found using grey relational grade analysis. It is concluded that low intensity and low to medium pulse overlap should be used for better dimensional accuracy. This study facilitates further understanding of laser material interaction for different process parameters and presents optimum laser process parameters for the fabrication of microchannel in alumina ceramic.
27
Jiang, J., W. J. Meng, G. B. Sinclair, and E. Lara-Curzio. "Further experiments and modeling for microscale compression molding of metals at elevated temperatures." Journal of Materials Research 22, no. 7 (July 2007): 1839–48. http://dx.doi.org/10.1557/jmr.2007.0252.
Анотація:
Replication of metallic high-aspect-ratio microscale structures (HARMS) by compression molding has been demonstrated recently. Molding replication of metallic HARMS can potentially lead to low-cost fabrication of a wide variety of metal-based microdevices. Understanding the mechanics of metal micromolding is critical for assessing the capabilities and limitations of this replication technique. This paper presents results of instrumented micromolding of Al. Measured molding response was rationalized with companion high-temperature tensile testing of Al using a simple mechanics model of the micromolding process. The present results suggest that resisting pressure on the mold insert during micromolding is governed primarily by the yield stress of the molded metal at the molding temperature and a frictional traction on the sides of the insert. The influence of strain rate is also considered.
28
Liu, Ze, Jinkui Chu, Ran Zhang, Chuanlong Guan, and Yuanyi Fan. "Preparation of an Integrated Polarization Navigation Sensor via a Nanoimprint Photolithography Process." Photonics 9, no. 11 (October 27, 2022): 806. http://dx.doi.org/10.3390/photonics9110806.
Анотація:
Based on the navigation strategy of insects utilizing the polarized skylight, an integrated polarization sensor for autonomous navigation is presented. The polarization sensor is fabricated using the proposed nanoimprint photolithography (NIPL) process by integrating a nanograting polarizer and an image chip. The NIPL process uses a UV-transparent variant template with nanoscale patterns and a microscale metal light-blocking layer. During the NIPL process, part of the resist material is pressed to fill into the nanofeatures of the variant template and is cured under UV exposure. At the same time, the other parts of the resist material create micropatterns according to the light-blocking layer. Polymer-based variant templates can be used for conformal contacts on non-flat substrates with excellent pattern transfer fidelity. The NIPL process is suitable for cross-scale micro–nano fabrication in wide applications. The measurement error of the polarization angle of the integrated polarization sensor is ±0.2°; thus, it will have a good application prospect in the polarization navigation application.
29
Snetkov, Petr P., Kseniia S. Zakharova, Maria I. Tyanutova, Svetlana N. Morozkina, Roman O. Olekhnovich, and Mayya V. Uspenskaya. "THE STUDY OF THE PHYSICAL PROPERTIES OF AQUEOUS-ORGANIC HYALURONAN ELECTROSPINNING SOLUTIONS." Bulletin of the Saint Petersburg State Institute of Technology (Technical University) 55 (2020): 16–21. http://dx.doi.org/10.36807/1998-9849-2020-55-81-16-21.
Анотація:
Hyaluronic acid (HA) is a naturally occurring polymer that is found in variety of tissues and biological fluids. Due to its unique properties such as biodegradability and biocompatibility, HA can be applied in fabrication of nanofibers for tissue engineering and wound healing. Electrospinning as one of the methods of creating such structures allows to obtain fibers and particles with nano- and microscale from polymer solutions utilizing the high voltage power supply. However, the electrospinning process directly depends upon different parameters, including physical characteristics of the polymer solutions. This paper reviews physical properties of aqueous-organic HA solutions considering their suitability for electrospinning
30
Hsiao, Alexander P., and Michael J. Heller. "Electric-Field-Directed Self-Assembly of Active Enzyme-Nanoparticle Structures." Journal of Biomedicine and Biotechnology 2012 (2012): 1–9. http://dx.doi.org/10.1155/2012/178487.
Анотація:
A method is presented for the electric-field-directed self-assembly of higher-order structures composed of alternating layers of biotin nanoparticles and streptavidin-/avidin-conjugated enzymes carried out on a microelectrode array device. Enzymes included in the study were glucose oxidase (GOx), horseradish peroxidase (HRP), and alkaline phosphatase (AP); all of which could be used to form a light-emitting microscale glucose sensor. Directed assembly included fabricating multilayer structures with 200 nm or 40 nm GOx-avidin-biotin nanoparticles, with AP-streptavidin-biotin nanoparticles, and with HRP-streptavidin-biotin nanoparticles. Multilayered structures were also fabricated with alternate layering of HRP-streptavidin-biotin nanoparticles and GOx-avidin-biotin nanoparticles. Results showed that enzymatic activity was retained after the assembly process, indicating that substrates could still diffuse into the structures and that the electric-field-based fabrication process itself did not cause any significant loss of enzyme activity. These methods provide a solution to overcome the cumbersome passive layer-by-layer assembly methods to efficiently fabricate higher-order active biological and chemical hybrid structures that can be useful for creating novel biosensors and drug delivery nanostructures, as well as for diagnostic applications.
31
Hashimoto, Masaaki, and Yoshihiro Taguchi. "Design and Fabrication of a Kirigami-Inspired Electrothermal MEMS Scanner with Large Displacement." Micromachines 11, no. 4 (March 30, 2020): 362. http://dx.doi.org/10.3390/mi11040362.
Анотація:
Large-displacement microelectromechanical system (MEMS) scanners are in high demand for a wide variety of optical applications. Kirigami, a traditional Japanese art of paper cutting and folding, is a promising engineering method for creating out-of-plane structures. This paper explores the feasibility and potential of a kirigami-inspired electrothermal MEMS scanner, which achieves large vertical displacement by out-of-plane film actuation. The proposed scanner is composed of film materials suitable for electrothermal self-reconfigurable folding and unfolding, and microscale film cuttings are strategically placed to generate large displacement. The freestanding electrothermal kirigami film with a 2 mm diameter and high fill factor is completely fabricated by careful stress control in the MEMS process. A 200 μm vertical displacement with 131 mW and a 20 Hz responsive frequency is experimentally demonstrated as a unique function of electrothermal kirigami film. The proposed design, fabrication process, and experimental test validate the proposed scanner’s feasibility and potential for large-displacement scanning with a high fill factor.
32
Peng, Zilong, Nairui Gou, Zilong Wei, Jiawei Zhao, Fei Wang, Jianjun Yang, Yinan Li та Hongbo Lan. "Fabrication of a Large-Area, Fused Polymer Micromold Based on Electric-Field-Driven (EFD) μ-3D Printing". Polymers 11, № 11 (18 листопада 2019): 1902. http://dx.doi.org/10.3390/polym11111902.
Анотація:
An electric-field-driven (EFD), μ-3D printed, fused polymer technique has been developed for the fabrication of large-area microscale prototype molds using typical polymer materials, including microcrystalline wax (MC-wax), polycaprolactone (PCL), and polymathic methacrylate (PMMA). This work proposes an alternative for large area microscale modes and overcomes the limitation of high cost in the traditional mold manufacturing industry. The EFD principle enables printing of fused polymers materials more than one order of magnitude lower than the nozzle diameter, contributing to the necking effect of the Taylor cone jet, which is the key factor to achieve the microscale manufacturing. Numerical simulation of electric field distribution between the meniscus and substrate was carried out to elucidate the dependence of electric field distribution on the meniscus condition of three types of polymers under printable voltage, and the electrical field parameters for the EFD μ-3D printing were determined. A number of experiments were printed successfully using a large range of viscosity materials, ranging from tens of mPa·s to hundreds of thousands of mPa·s of PCL and PMMA. The differences in parameters of different materials, such as viscosity, tensile properties, and surface energy, were studied to assess their use in different fields. Using proper process parameters and a nozzle with an inner diameter of 200 μm, three different application cases were completed, including a Wax microarray and microchannel with a minimum dot diameter of 20 μm, a PCL mesh structure with a minimum line width of 5 μm, and a PMMA large-area mold with a maximum aspect ratio of 0.8. Results show that the EFD μ-3D printing has the outstanding advantages of high printing resolution and polymer material universality.
33
Kranz, Michael, Mark Allen, and Tracy Hudson. "In-Situ Wafer-Level Polarization of Electret Films in MEMS Acoustic Sensor Arrays." Additional Conferences (Device Packaging, HiTEC, HiTEN, and CICMT) 2011, DPC (January 1, 2011): 001732–60. http://dx.doi.org/10.4071/2011dpc-wp24.
Анотація:
MEMS-based electret and polymer piezoelectric transduction techniques have been reported for both acoustic sensors and energy harvesters. Common techniques employed in MEMS polymer polarization include corona discharge and backlighted thyratron. This paper reports a method for post-fabrication in-situ polarization of polymer films embedded within the MEMS device itself. The method utilizes microplasma discharges with self-aligned charging grids integrated within the device to charge fluoropolymer films in a fashion similar to the common corona discharge technique. This in-situ approach enables the integration of uncharged polymer films into MEMS and subsequent post-fabrication and post-packaging polarization, simultaneously enabling the formation of buried or encapsulated electrets as well as eliminating the need to restrict fabrication and packaging processes that might otherwise discharge pre-charged materials. CYTOP, a thermoplastic fluoropolymer encapsulant for electronics, is used as a polymer electret in the current process because it can be spin-cast, has a high resistivity, and is easily etched in oxygen plasma. A microscale charging grid structure is then fabricated and suspended a short distance above the polymer film. After fabrication of the charging grid, standard microfabrication steps are performed to build a single-chip array of MEMS capacitive acoustic sensors designed to capture and analyze waveforms from impacts. After completing the entire fabrication and packaging flow, the polarization process is performed. When energized by a high voltage, the sharp metal edges of the charging grid lead to high dielectric fields that ionize the air in the gap and force electric charge onto the polymer surface. Final sensor arrays have been demonstrated and applied in the classification of acoustic stress pulses generated during impacts of various materials.
34
Wang, Wei, Wei Guo Liu, Jin Long Zou, and Peng Fei Huo. "A MEMS Safe and Arm Device for Spin Stabilized Ammunition Fuze." Advanced Materials Research 403-408 (November 2011): 4593–97. http://dx.doi.org/10.4028/www.scientific.net/amr.403-408.4593.
Анотація:
In order to realize the miniaturization of fuze safety mechanism, a novel MEMS safe and arm is proposed through concept, analysis, design and initial prototyping. A microscale inertial mechanical logic for mechanical safe and arm functions in the form of sliders, springs, and locks that interact on a planar substrate in response to setback acceleration and centrifugal force to thereby arm the fuze, and the bulk fabrication process were analyzed. The safety criteria, design principles, modeling and simulation methods for arming slider, setback lock, and arming lock are introduced. Air gun testing demonstrates the feasibility of MEMS safe and arm device and the validity of the design method.
35
De Pasquale, Giorgio. "Additive Manufacturing of Micro-Electro-Mechanical Systems (MEMS)." Micromachines 12, no. 11 (November 8, 2021): 1374. http://dx.doi.org/10.3390/mi12111374.
Анотація:
Recently, additive manufacturing (AM) processes applied to the micrometer range are subjected to intense development motivated by the influence of the consolidated methods for the macroscale and by the attraction for digital design and freeform fabrication. The integration of AM with the other steps of conventional micro-electro-mechanical systems (MEMS) fabrication processes is still in progress and, furthermore, the development of dedicated design methods for this field is under development. The large variety of AM processes and materials is leading to an abundance of documentation about process attempts, setup details, and case studies. However, the fast and multi-technological development of AM methods for microstructures will require organized analysis of the specific and comparative advantages, constraints, and limitations of the processes. The goal of this paper is to provide an up-to-date overall view on the AM processes at the microscale and also to organize and disambiguate the related performances, capabilities, and resolutions.
36
Hu, Yanlei, Zhaoxin Lao, Benjamin P. Cumming, Dong Wu, Jiawen Li, Haiyi Liang, Jiaru Chu, Wenhao Huang, and Min Gu. "Laser printing hierarchical structures with the aid of controlled capillary-driven self-assembly." Proceedings of the National Academy of Sciences 112, no. 22 (May 18, 2015): 6876–81. http://dx.doi.org/10.1073/pnas.1503861112.
Анотація:
Capillary force is often regarded as detrimental because it may cause undesired distortion or even destruction to micro/nanostructures during a fabrication process, and thus many efforts have been made to eliminate its negative effects. From a different perspective, capillary force can be artfully used to construct specific complex architectures. Here, we propose a laser printing capillary-assisted self-assembly strategy for fabricating regular periodic structures. Microscale pillars are first produced by localized femtosecond laser polymerization and are subsequently assembled into periodic hierarchical architectures with the assistance of controlled capillary forces in an evaporating liquid. Spatial arrangements, pillar heights, and evaporation processes are readily tuned to achieve designable ordered assemblies with various geometries. Reversibility of the assembly is also revealed by breaking the balance between the intermolecular force and the elastic standing force. We further demonstrate the functionality of the hierarchical structures as a nontrivial tool for the selective trapping and releasing of microparticles, opening up a potential for the development of in situ transportation systems for microobjects.
37
Joshi-Imre, Alexandra, and Sven Bauerdick. "Direct-Write Ion Beam Lithography." Journal of Nanotechnology 2014 (2014): 1–26. http://dx.doi.org/10.1155/2014/170415.
Анотація:
Patterning with a focused ion beam (FIB) is an extremely versatile fabrication process that can be used to create microscale and nanoscale designs on the surface of practically any solid sample material. Based on the type of ion-sample interaction utilized, FIB-based manufacturing can be both subtractive and additive, even in the same processing step. Indeed, the capability of easily creating three-dimensional patterns and shaping objects by milling and deposition is probably the most recognized feature of ion beam lithography (IBL) and micromachining. However, there exist several other techniques, such as ion implantation- and ion damage-based patterning and surface functionalization types of processes that have emerged as valuable additions to the nanofabrication toolkit and that are less widely known. While fabrication throughput, in general, is arguably low due to the serial nature of the direct-writing process, speed is not necessarily a problem in these IBL applications that work with small ion doses. Here we provide a comprehensive review of ion beam lithography in general and a practical guide to the individual IBL techniques developed to date. Special attention is given to applications in nanofabrication.
38
Liu, Yuxia, Kai Jiang, and Shuting Yang. "Integrated Anode Electrode Composited Cu–Sn Alloy and Separator for Microscale Lithium Ion Batteries." Materials 12, no. 4 (February 18, 2019): 603. http://dx.doi.org/10.3390/ma12040603.
Анотація:
A novel integrated electrode structure was designed and synthesized by direct electrodepositing of Cu–Sn alloy anode materials on the Celgard 2400 separator (Cel-CS electrode). The integrated structure of the Cel-CS electrode not only greatly simplifies the battery fabrication process and increases the energy density of the whole electrode, but also buffers the mechanical stress caused by volume expansion of Cu–Sn alloy active material; thus, effectively preventing active material falling off from the substrate and improving the cycle stability of the electrode. The Cel-CS electrode exhibits excellent cycle performance and superior rate performance. A capacity of 728 mA·h·g−1 can be achieved after 250 cycles at the current density of 100 mA·g−1. Even cycled at a current density of 5 A·g−1 for 650 cycles, the Cel-CS electrode maintained a specific capacity of 938 mA·h·g−1, which illustrates the potential application prospects of the Cel-CS electrode in microelectronic devices and systems.
39
Chi, Xiang, Xinyu Zhang, Zongan Li, Zhe Yuan, Liya Zhu, Feng Zhang, and Jiquan Yang. "Fabrication of Microfluidic Chips Based on an EHD-Assisted Direct Printing Method." Sensors 20, no. 6 (March 11, 2020): 1559. http://dx.doi.org/10.3390/s20061559.
Анотація:
Microfluidic chips have been widely used in many areas such as biology, environmental monitoring, and micromixing. With the increasing popularity and complexity of microfluidic systems, rapid and convenient approaches for fabricating microfluidic chips are necessary. In this study, a method based on EHD (electrohydrodynamic)-assisted direct printing is proposed. Firstly, the principle of EHD-assisted direct printing was analyzed. The influence of the operating voltage and moving speed of the work table on the width of a paraffin wax model was studied. Then, two kinds of paraffin wax molds for micromixing with channel widths of 120 μm were prepared. A polydimethylsiloxane (PDMS) micromixer was fabricated by replicating the paraffin wax mold, and the micromixing of blue and yellow dye was realized. The results show that EHD-assisted direct printing can be used to make complex microscale structures, which has the potential to greatly simplify the manufacturing process.
40
Han, Seungkyu, Matthew Zielewski, David Martinez Holguin, Monica Michel Parra, and Namsoo Kim. "Optimization of AZ91D Process and Corrosion Resistance Using Wire Arc Additive Manufacturing." Applied Sciences 8, no. 8 (August 6, 2018): 1306. http://dx.doi.org/10.3390/app8081306.
Анотація:
Progress on Additive Manufacturing (AM) techniques focusing on ceramics and polymers evolves, as metals continue to be a challenging material to manipulate when fabricating products. Current methods, such as Selective Laser Sintering (SLS) and Electron Beam Melting (EBM), face many intrinsic limitations due to the nature of their processes. Material selection, elevated cost, and low deposition rates are some of the barriers to consider when one of these methods is to be used for the fabrication of engineering products. The research presented demonstrates the use of a Wire and Arc Additive Manufacturing (WAAM) system for the creation of metallic specimens. This project explored the feasibility of fabricating elements made from magnesium alloys with the potential to be used in biomedical applications. It is known that the elastic modulus of magnesium closely approximates that of natural bone than other metals. Thus, stress shielding phenomena can be reduced. Furthermore, the decomposition of magnesium shows no harm inside the human body since it is an essential element in the body and its decomposition products can be easily excreted through the urine. By alloying magnesium with aluminum and zinc, or rare earths such as yttrium, neodymium, cerium, and dysprosium, the structural integrity of specimens inside the human body can be assured. However, the in vivo corrosion rates of these products can be accelerated by the presence of impurities, voids, or segregation created during the manufacturing process. Fast corrosion rates would produce improper healing, which, in turn, involve subsequent surgical intervention. However, in this study, it has been proven that magnesium alloy AZ91D produced by WAAM has higher corrosion resistance than the cast AZ91D. Due to its structure, which has porosity or cracking only at the surface of the individual printed lines, the central sections present a void-less structure composed by an HCP magnesium matrix and a high density of well dispersed aluminum-zinc rich precipitates. Also, specimens created under different conditions have been analyzed in the macroscale and microscale to determine the parameters that yield the best visual and microstructural results.
41
Zhang, Jianrui, Yabin Yan, and Bo Li. "Selective Laser Melting (SLM) Additively Manufactured CoCrFeNiMn High-Entropy Alloy: Process Optimization, Microscale Mechanical Mechanism, and High-Cycle Fatigue Behavior." Materials 15, no. 23 (December 1, 2022): 8560. http://dx.doi.org/10.3390/ma15238560.
Анотація:
The equiatomic CoCrFeNiMn high-entropy alloy (HEA) possesses excellent properties including exceptional strength–ductility synergy, high corrosion resistance, and good thermal stability. Selective laser melting (SLM) additive manufacturing facilitates the convenient fabrication of the CoCrFeNiMn HEA parts with complex geometries. Here, the SLM process optimization was conducted to achieve a high relative density of as-built CoCrFeNiMn HEA bulks. The mechanisms of process-induced defects and process control were elucidated. The microscale mechanical behaviors were analyzed through in situ scanning electron microscopy observation during the compression tests on micro-pillars of the as-built HEA. The stress–strain characteristics by repeated slip and mechanism of “dislocation avalanche” during the compression of micro-pillars were discussed. The high-cycle fatigue tests of the as-built HEA were performed. It was found that a large number of nano-twins were induced by the fatigue, causing a non-negligible cycle softening phenomenon. The effects of promoted ductility due to the fatigue-induced nano-twins were illustrated. This work has some significance for the engineering application of the SLM additively manufactured CoCrFeNiMn HEA parts.
42
Huan, Junjun, Vamsy P. Chodavarapu, George Xereas, and Charles Allan. "Microfabrication and Packaging Process for a Single-Chip Position, Navigation, and Timing System." International Symposium on Microelectronics 2017, no. 1 (October 1, 2017): 000208–14. http://dx.doi.org/10.4071/isom-2017-wa25_143.
Анотація:
Abstract The Global Positioning System (GPS) is the primary means of Positioning, Navigation, and Timing (PNT) for most civilian and military systems and applications. The rapid growth in autonomous systems has created a widespread interest in self-contained Inertial Navigation System (INS) for precise navigation and guidance in the absence of GPS. The microscale PNT systems need both specialized and low cost fabrication technologies to cost effectively bring these technologies to market. We describe an ultra-clean (low leak rate) wafer-level vacuum encapsulation microfabrication process of Micro-Electro-Mechanical Systems (MEMS) based sensors and devices. Using this process we have fabricated inertial sensors, frequency reference resonators, and pressure sensors. In addition to providing excellent resistance to shock and vibration, this combined microfabrication and packaging method would allow the use of high volume low cost plastic packaging at the device level. The microfabrication process is an 8” wafer process based on high aspect ratio bulk micromachining of a 30 μm thick single-crystal silicon device layer that is vacuum encapsulated at 10 mTorr between two silicon wafers with the demonstrated leak rate of only 6.5 × 10−18 atm cm3/s.
43
Jain, Vivek, Apurbba Kumar Sharma, and Pradeep Kumar. "Recent Developments and Research Issues in Microultrasonic Machining." ISRN Mechanical Engineering 2011 (April 4, 2011): 1–15. http://dx.doi.org/10.5402/2011/413231.
Анотація:
Demand for micromachining has been on the rise in recent years owing to increasing miniaturization. Production of parts in microscale, especially with brittle materials, is challenging. Ultrasonic micromachining has been gaining popularity as a new alternative in fabrication of such parts. The process gives a machining option for geometrically challenging and/or brittle material parts that are difficult to machine by conventional processes. In the recent years, possibilities have been explored to improve the “Unit Removal” in microultrasonic machining (micro-USM). However, the research in the area is yet to attain momentum. The present paper is an attempt to present the state of the art in the area of micro-USM based on the literature. Developments in the critical areas of the process like machine tool technology, machining tool head, transducers, and precision attainable in the process with challenges have been discussed. Potential research issues have been explored for future work. Possible application areas have been identified.
44
Xu, Jiushuai, Klass Strempel, Hao Zhou, Andreas Waag, Maik Bertke, Angelika Schmidt, and Erwin Peiner. "Area-Selective Growth of Aligned ZnO Nanorod Arrays for MEMS Device Applications." Proceedings 2, no. 13 (November 23, 2018): 887. http://dx.doi.org/10.3390/proceedings2130887.
Анотація:
ZnO nanorods (NRs) arrays with good vertical alignment were selectively grown on microscale patterned surfaces by a MEMS-compatible, low-temperature chemical-bath deposition method (CBD). The direct-current (DC) sputtered and subsequently annealed ZnO seed-layer was found to have a crucial effect on the ZnO NRs growth. Depending on the pre-annealing temperature between 200 °C and 700 °C, which is compatible with our microcantilever fabrication process, diameters and area densities of the NRs of 60–99 nm and 17–27 µm−2 were observed, respectively, with the best alignment at 600 °C. A surface-area enlargement factor of 48 was achieved with respect to a ZnO layer indicating the potential of ZnO NRs arrays for MEMS applications, such as gas sensing.
45
Pereira, G. S., C. P. Oliveira, and J. A. Souza. "COMPARISON BETWEEN TWO WAYS OF MODELING THE FLOW RESISTANCE IN A POROUS MEDIUM." Revista de Engenharia Térmica 22, no. 1 (April 28, 2023): 40. http://dx.doi.org/10.5380/reterm.v22i1.90974.
Анотація:
Pieces manufactured from polymeric composites are known for their good mechanical properties and low specific weight. However, controlling their fabrication process requires precise knowledge of the reinforcement and resin physical properties. This is needed to ensure that defective composites are not manufactured. Investigations into these materials physical properties are generally carried out experimentally, which makes it difficult to observe what happens on microscale level. Present work aims to analyze, and compare, flow behavior in a porous medium using two approaches: a) flow resistance is modeled with Darcy's Law, and b) fluid flow is solved through the reinforcement fibers in a micro-sample level. Medium permeability determination was used in results comparison. A good quantitative agreement in predictions obtained with both methods was observed.
46
Gao, Kuan, Xin Zhang, Baoxi Liu, Jining He, Jianhang Feng, Puguang Ji, Wei Fang, and Fuxing Yin. "The Deformation Characteristics, Fracture Behavior and Strengthening-Toughening Mechanisms of Laminated Metal Composites: A Review." Metals 10, no. 1 (December 19, 2019): 4. http://dx.doi.org/10.3390/met10010004.
Анотація:
Multilayer metal composites have great application prospects in automobiles, ships, aircraft and other manufacturing industries, which reveal their superior strength, toughness, ductility, fatigue lifetime, superplasticity and formability. This paper presents the various mechanical properties, deformation characteristics and strengthening–toughening mechanisms of laminated metal matrix composites during the loading and deformation process, and that super-high mechanical properties can be obtained by adjusting the fabrication process and structure parameters. In the macroscale, the interface bonding status and layer thickness can effectively affect the fracture, impact toughness and tensile fracture elongation of laminated metal matrix composites, and the ductility and toughness cannot be fitting to the rule of mixture (ROM). However, the elastic properties, yield strength and ultimate strength basically follow the rule of mixture. In the microscale, the mechanical properties, deformation characteristics, fracture behavior and toughening mechanisms of laminated composites reveal the obvious size effect.
47
Sulaiman H., A. J., M. H. Aiman, M. Ishak, M. M. Quazi, T. Zaharinie, and T. Ariga. "Vacuum brazing of titanium alloy to stainless steel enhance by fiber laser surface texturing." Journal of Mechanical Engineering and Sciences 15, no. 4 (December 15, 2021): 8601–7. http://dx.doi.org/10.15282/jmes.15.4.2021.12.0678.
Анотація:
A method for improving the brazing joining strength of Titanium alloy/Stainless steel fabricated through fibre laser surface texturing is introduced because it is a simple process that does not require the fabrication of complicated interlayers. However, previous research shows that a milimeter scale was fabricated by surface modification for dissimilar brazing join, yielding insignificant results and limiting the application and degree of enhancement. Fiber laser ablation was used in this study to create microscale periodic patterns (grooves) on a stainless steel surface. No defect or damage induced during laser surface texturing process. The groove dimension was tunable by controlling the laser parameters. Vacuum brazing of Ti6Al4V to 316L stainless steel with surface texturing, the average joint strength was 22.1 MPa, 34% of increase of joining strength compared to unprocessed flat surface. The combination of laser surface texturing and brazing proven effectively on joining strength enhancement.
48
Lee, Sung, Hoon Yi, Cheol Park, Hoon Jeong, and Moonkyu Kwak. "Continuous Tip Widening Technique for Roll-to-Roll Fabrication of Dry Adhesives." Coatings 8, no. 10 (September 30, 2018): 349. http://dx.doi.org/10.3390/coatings8100349.
Анотація:
In this study, we reported continuous partial curing and tip-shaped modification methods for continuous production of dry adhesive with microscale mushroom-shaped structures. Typical fabrication methods of dry adhesive with mushroom-shaped structures are less productive due to the failure of large tips on pillar during demolding. To solve this problem, a typical pillar structure was fabricated through partial curing, and tip widening was realized through applying the proper pressure. Polyurethane acrylate was used in making the mushroom structure using two-step UV-assisted capillary force lithography (CFL). To make the mushroom structure, partial curing was performed on the micropillar, followed by tip widening. Dry adhesives with properties similar to those of typical mushroom-shaped dry adhesives were fabricated with reasonable adhesion force using the two-step UV-assisted CFL. This production technology was applied to the roll-to-roll process to improve productivity, thereby realizing continuous production without any defects. Such a technology is expected to be applied to various fields by achieving the productivity improvement of dry adhesives, which is essential for various applications.
49
Dodampegama, Shanuka, Amith Mudugamuwa, Menaka Konara, Nisal Perera, Dinindu De Silva, Uditha Roshan, Ranjith Amarasinghe, Nirosh Jayaweera, and Hiroki Tamura. "A Review on the Motion of Magnetically Actuated Bio-Inspired Microrobots." Applied Sciences 12, no. 22 (November 14, 2022): 11542. http://dx.doi.org/10.3390/app122211542.
Анотація:
Nature consists of numerous solutions to overcome challenges in designing artificial systems. Various actuation mechanisms have been implemented in microrobots to mimic the motion of microorganisms. Such bio-inspired designs have contributed immensely to microscale developments. Among the actuation mechanisms, magnetic actuation is widely used in bio-inspired microrobotic systems and related propulsion mechanisms used by microrobots to navigate inside a magnetic field and are presented in this review. In addition, the considered robots are in microscale, and they can swim inside a fluidic environment with a low Reynolds number. In relation to microrobotics, mimicry of bacteria flagella, sperm flagella, cilia, and fish are significant. Due to the fact that these biological matters consist of different propulsion mechanisms, the effect of various parameters was investigated in the last decade and the review presents a summary that enhances understanding of the working principle of propulsion mechanisms. In addition, the effect of different parameters on the various speeds of the existing microrobots was analyzed to identify their trends. So, the swimming speeds of the microrobots show an upward trend with increasing body length, frequency, magnetic flux density, and helix angle. Microfabrication techniques play a significant role in the microscale because the device designs are highly dependent on the availability of the techniques. The presented microrobots were manufactured by 3D/4D photolithography and rapid prototyping techniques. Proper materials enable effective fabrication of microrobots using the mentioned techniques. Therefore, magnetically active material types, matrix materials, biocompatible and biodegradable materials are presented in this study. Utilizing biocompatible and biodegradable materials avoids adverse effects to the organs that could occur otherwise. In addition, magnetic field generation is significant for the propulsion of such microrobots. We conclude the review with an overview of the biomimicry of microrobots and magnetically actuated robot propulsion.
50
Huang, Hong, and Theresa Hill. "Understanding Key Factors during Dod Inkjet Printing Towards Precise Fabrication of Micro Energy Systems." ECS Meeting Abstracts MA2022-01, no. 35 (July 7, 2022): 1430. http://dx.doi.org/10.1149/ma2022-01351430mtgabs.
Анотація:
There is an ever-increasing need for micro energy systems that can power miniature, unmanned, or remotely-located devices. Drop-on-Demand (DOD) inkjet fabrication is uniquely positioned for this demand due to its low-cost processing with microscale resolution, high throughput, reproducibility, and ease in shape design. This study seeks to capitalize on the advantages of DOD inkjet printing for application to manufacturing micro energy conversion/storage systems, by defining the fundamental jet kinematics and key factors underpinning the inkjet printing process. The ink used in this study was a dilute colloidal ink suspension composed of a common solid oxide fuel cell (SOFC) cathode material [La0.6Sr0.4Fe0.8Co0.2O3 (LSFC)] and organic solvent α-terpineol. The results were evaluated systematically in terms os final deposition quality, resolution, and microstructure. Favorable fluid kinematics were identified that attained uniform, well-shaped, circular 0-D dots about 0.1 µm thick and 60 µm in diameter. To increases the microfeature thickness and x/y plane dimensions , multiple and/or sequential ink passes were employed. For printing 1-D lines, the spacing between droplets was imperative to fabricating quality micro features. Using appropriate conditions, 1-D lines with x/y dimensions < 100 µm and controllable z axis dimensions at 0.1 µm per printing pass with dense, open or networked microstructures were demonstrated. 2-D planes at the dimensions as small as 100 µm by 100 µm were also achieved with smooth surface and continuous intra-planar ceramic coverage. In the course of post-processing the inkjetted cathodes, it was observed that the submicron cathode films printed at optimal conditions, after being sintered at controlled conditions, were uniform, smooth and free of cracks or delamination. This research demonstrated through fundamental understanding and control of the inkjet fabrication process, cathode features can be printed with controlled dimension and quality towards producing a functioning micro SOFC operable at low temperatures. The knowledge gained from this research will be appliable to other micro energy conversion and storage systems.