Feature Papers of Micromachines in "Materials and Processing" 2022

A special issue of Micromachines (ISSN 2072-666X). This special issue belongs to the section "D:Materials and Processing".

Deadline for manuscript submissions: closed (31 December 2022) | Viewed by 37638

Special Issue Editor

Terasaki Institute for Biomedical Innovation, 1018 Westwood Blvd, Los Angeles, CA 90024, USA
Interests: bio-micro-electro-mechanical systems (BioMEMS); biomedical and implantable devices; biosensors; organs-on-a-chip; micro- and nanosensors for monitoring organs-on-a-chip; flexible electronics and sensors for wound healing; packaging and encapsulation of implantable devices; biomaterials; biofabrication
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Special Issue Information

Dear Colleagues,

We are pleased to announce the Special Issue entitled "Feature Papers of Micromachines in Materials and Processing 2022". Over the past several years, we have worked in conjunction with excellent scholars and research groups to publish several high-impact high-quality manuscripts, receiving a large number of views and citations. Our goal is to publish the latest scientific and technological advances in areas related to micro/nanofabrication with applications in biomedical sciences and biology, materials, semiconductors, photonics, and energy, with the hopes of providing great contributions to the scientific community.

This Special Issue will be a collection of high-quality papers from excellent scholars around the world, both original research articles and comprehensive review papers being welcome, published, with full open access after a peer review, benefiting both authors and readers.

You are welcome to send short proposals for the submission of Feature Papers to our Editorial Office (aria.zeng@mdpi.com) before the submission. The proposals will first be evaluated by Editors, and so please note that selected full papers will still be subject to a thorough and rigorous peer review.

We look forward to receiving your excellent work.

Prof. Dr. Mehmet Remzi Dokmeci
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Micromachines is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2600 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • biomedical microdevices
  • micro/nanofabrication
  • BioMEMS
  • organs-on-a-chip
  • minimally invasive devices
  • wearable devices
  • biosensors
  • 3D bioprinting
  • MEMS and CMOS technologies
  • artificial intelligence with applications in micro/nanofabrication and sensors
  • point of care devices
  • III-V devices
  • thin film transistors

Published Papers (15 papers)

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Research

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10 pages, 1826 KiB  
Article
Fabrication of Multi-Material Pneumatic Actuators and Microactuators Using Stereolithography
by Qingchuan Song, Yunong Chen, Peilong Hou, Pang Zhu, Dorothea Helmer, Frederik Kotz-Helmer and Bastian E. Rapp
Micromachines 2023, 14(2), 244; https://doi.org/10.3390/mi14020244 - 18 Jan 2023
Cited by 6 | Viewed by 2025
Abstract
Pneumatic actuators are of great interest for device miniaturization, microactuators, soft robots, biomedical engineering, and complex control systems. Recently, multi-material actuators have become of high interest to researchers due to their comprehensive range of suitable applications. Three-dimensional (3D) printing of multi-material pneumatic actuators [...] Read more.
Pneumatic actuators are of great interest for device miniaturization, microactuators, soft robots, biomedical engineering, and complex control systems. Recently, multi-material actuators have become of high interest to researchers due to their comprehensive range of suitable applications. Three-dimensional (3D) printing of multi-material pneumatic actuators would be the ideal way to fabricate customized actuators, but so far, this is mostly limited to deposition-based methodologies, such as fused deposition modeling (FDM) or Polyjetting. Vat-based stereolithography is one of the most relevant high-resolution 3D printing methods but is only rarely utilized in the multi-material 3D printing of materials. This study demonstrated multi-material stereolithography using combinations of materials with different Young’s moduli, i.e., 0.5 MPa and 1.1 GPa, for manufacturing pneumatic actuators and microactuators with a resolution as small as 200 μm. These multi-material actuators have advantages over single-material actuators in terms of their deformation controllability and ease of assembly. Full article
(This article belongs to the Special Issue Feature Papers of Micromachines in "Materials and Processing" 2022)
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14 pages, 12357 KiB  
Article
An Investigation into the Effects of Electric Field Uniformity on Electrospun TPU Fiber Nano-Scale Morphology
by Aaron Morehouse, Kelton C. Ireland and Gobinda C. Saha
Micromachines 2023, 14(1), 199; https://doi.org/10.3390/mi14010199 - 13 Jan 2023
Viewed by 1242
Abstract
ANSYS Maxwell was used to replicate the conditions of two potential electrospinning configurations: a needle–plate and a parallel-plate configuration. Simulations showed that the electric field generated within the parallel-plate configuration was much more uniform than that within the needle–plate configuration. Both configurations were [...] Read more.
ANSYS Maxwell was used to replicate the conditions of two potential electrospinning configurations: a needle–plate and a parallel-plate configuration. Simulations showed that the electric field generated within the parallel-plate configuration was much more uniform than that within the needle–plate configuration. Both configurations were assembled and used electrospin fibers at three different spinning distances (10 cm, 12 cm, and 15 cm), at a consistent electric field strength of 1.7 kV/cm. Scanning electron microscopy was used to compare the morphologies of the fibers produced in both configurations in order to confirm whether a more uniform electric field yielded thinner fibers. The results show that the needle–plate configuration produced finer fibers than the parallel-plate configuration at all three spinning distances. However, there was no difference in the fiber diameters produced at the 12 and 15 cm spinning distances within the needle–plate configuration, implying thinning may only occur up to a certain distance in this configuration. Full article
(This article belongs to the Special Issue Feature Papers of Micromachines in "Materials and Processing" 2022)
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14 pages, 6832 KiB  
Article
Trapping of a Single Microparticle Using AC Dielectrophoresis Forces in a Microfluidic Chip
by Yanjuan Wang, Ning Tong, Fengqi Li, Kai Zhao, Deguang Wang, Yijie Niu, Fengqiang Xu, Jiale Cheng and Junsheng Wang
Micromachines 2023, 14(1), 159; https://doi.org/10.3390/mi14010159 - 08 Jan 2023
Cited by 2 | Viewed by 1474
Abstract
Precise trap and manipulation of individual cells is a prerequisite for single-cell analysis, which has a wide range of applications in biology, chemistry, medicine, and materials. Herein, a microfluidic trapping system with a 3D electrode based on AC dielectrophoresis (DEP) technology is proposed, [...] Read more.
Precise trap and manipulation of individual cells is a prerequisite for single-cell analysis, which has a wide range of applications in biology, chemistry, medicine, and materials. Herein, a microfluidic trapping system with a 3D electrode based on AC dielectrophoresis (DEP) technology is proposed, which can achieve the precise trapping and release of specific microparticles. The 3D electrode consists of four rectangular stereoscopic electrodes with an acute angle near the trapping chamber. It is made of Ag–PDMS material, and is the same height as the channel, which ensures the uniform DEP force will be received in the whole channel space, ensuring a better trapping effect can be achieved. The numerical simulation was conducted in terms of electrode height, angle, and channel width. Based on the simulation results, an optimal chip structure was obtained. Then, the polystyrene particles with different diameters were used as the samples to verify the effectiveness of the designed trapping system. The findings of this research will contribute to the application of cell trapping and manipulation, as well as single-cell analysis. Full article
(This article belongs to the Special Issue Feature Papers of Micromachines in "Materials and Processing" 2022)
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7 pages, 1002 KiB  
Article
Mechanical Control of the Optical Bandgap in One-Dimensional Photonic Crystals
by V. Paige Stinson, Nuren Shuchi, Micheal McLamb, Glenn D. Boreman and Tino Hofmann
Micromachines 2022, 13(12), 2248; https://doi.org/10.3390/mi13122248 - 17 Dec 2022
Cited by 9 | Viewed by 1695
Abstract
Over the last several years, two-photon polymerization has been a popular fabrication approach for photonic crystals due to its high spatial resolution. One-dimensional photonic crystals with photonic bandgap reflectivities over 90% have been demonstrated for the infrared spectral range. With the success of [...] Read more.
Over the last several years, two-photon polymerization has been a popular fabrication approach for photonic crystals due to its high spatial resolution. One-dimensional photonic crystals with photonic bandgap reflectivities over 90% have been demonstrated for the infrared spectral range. With the success of these structures, methods which can provide tunability of the photonic bandgap are being explored. In this study, we demonstrate the use of mechanical flexures in the design of one-dimensional photonic crystals fabricated by two-photon polymerization for the first time. Experimental results show that these photonic crystals provide active mechanically induced spectral control of the photonic bandgap. An analysis of the mechanical behavior of the photonic crystal is presented and elastic behavior is observed. These results suggest that one-dimensional photonic crystals with mechanical flexures can successfully function as opto-mechanical structures. Full article
(This article belongs to the Special Issue Feature Papers of Micromachines in "Materials and Processing" 2022)
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20 pages, 8473 KiB  
Article
Preparation of FeCo/C-N and FeNi/C-N Nanocomposites from Acrylamide Co-Crystallizates and Their Use as Lubricant Additives
by Igor E. Uflyand, Victoria E. Burlakova, Ekaterina G. Drogan, Igor Yu. Zabiyaka, Kamila A. Kydralieva, Gulsara D. Kugabaeva and Gulzhian I. Dzhardimalieva
Micromachines 2022, 13(11), 1984; https://doi.org/10.3390/mi13111984 - 16 Nov 2022
Cited by 3 | Viewed by 1261
Abstract
FeCo and FeNi nanoalloy particles encapsulated in a nitrogen-doped carbonized shell (FeCo/C-N and FeNi/C-N) were synthesized by thermolysis at 400 °C of polyacrylamide complexes after frontal polymerization of co-crystallizate of Fe and Co or Ni nitrates and acrylamide. During the thermolysis of polyacrylamide [...] Read more.
FeCo and FeNi nanoalloy particles encapsulated in a nitrogen-doped carbonized shell (FeCo/C-N and FeNi/C-N) were synthesized by thermolysis at 400 °C of polyacrylamide complexes after frontal polymerization of co-crystallizate of Fe and Co or Ni nitrates and acrylamide. During the thermolysis of polyacrylamide complexes in a self-generated atmosphere, Co(II) or Ni(II) and Fe(III) cations are reduced to form FeCo and FeNi nanoalloy particles, while polyacrylamide simultaneously forms a nitrogen-doped carbon shell layer. This unique architecture provides high chemical and thermal stability of the resulting nanocomposites. The average crystallite size of FeCo and FeNi nanoparticles is 10 and 12 nm, respectively. The nanocomposites were studied by X-ray diffraction, atomic force microscopy, scanning electron microscopy, and high-resolution transmission electron microscopy. The nanocomposites have been tested as antifriction and antiwear additives in lubricating oils. The optimal concentrations of nanoparticles were determined, at which the antifriction and antiwear properties of the lubricant manifest themselves in the best possible way. Full article
(This article belongs to the Special Issue Feature Papers of Micromachines in "Materials and Processing" 2022)
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12 pages, 3874 KiB  
Article
Temperature Sensing Shape Morphing Antenna (ShMoA)
by Wenxin Zeng, Wei Wang and Sameer Sonkusale
Micromachines 2022, 13(10), 1673; https://doi.org/10.3390/mi13101673 - 04 Oct 2022
Cited by 5 | Viewed by 1836
Abstract
Devices that can morph their functions on demand provide a rich yet unexplored paradigm for the next generation of electronic devices and sensors. For example, an antenna that can morph its shape can be used to adapt communication to different wireless standards or [...] Read more.
Devices that can morph their functions on demand provide a rich yet unexplored paradigm for the next generation of electronic devices and sensors. For example, an antenna that can morph its shape can be used to adapt communication to different wireless standards or improve wireless signal reception. We utilize temperature-sensitive shape memory alloys (SMA) to realize a shape morphing antenna (ShMoA). In the designed architecture, multiple conjoined shape memory alloy sections form the antenna. The shape morphing of this antenna is achieved through temperature control. Different temperature threshold levels are used for programming the shape. Besides its conventional use for RF applications, ShMoA can serve as a multi-level temperature sensor, analogous to thermoreceptors in an insect antenna. ShMoA essentially combines the function of temperature sensing, embedded computing for detection of threshold crossings, and radio frequency readout, all in the single construct of a shape-morphing antenna (ShMoA) without the need for any battery or peripheral electronics. The ShMoA can be employed as bio-inspired wireless temperature sensing antennae on mobile robotic flies, insects, drones and other robots. It can also be deployed as programmable antennas for multi-standard wireless communication. Full article
(This article belongs to the Special Issue Feature Papers of Micromachines in "Materials and Processing" 2022)
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7 pages, 2437 KiB  
Article
Ultra-Wideband Power Amplifier Design Strategy for 5G Sub-6-GHz Applications
by Jorge Julián Moreno Rubio, Edison Ferney Angarita Malaver and Jairo Alonso Mesa Lara
Micromachines 2022, 13(9), 1541; https://doi.org/10.3390/mi13091541 - 17 Sep 2022
Viewed by 1906
Abstract
This paper presents a strategy to design ultrawideband power amplifiers with a fractional bandwidth of approximately 200%. It exploits a simple output matching network, which consists of a series transmission line together with a shunt stub, to compensate the output parasitic network of [...] Read more.
This paper presents a strategy to design ultrawideband power amplifiers with a fractional bandwidth of approximately 200%. It exploits a simple output matching network, which consists of a series transmission line together with a shunt stub, to compensate the output parasitic network of the device. Following this, a multisection transformer is implemented to obtain the optimal load at the intrinsic drain plane. As design examples, several output matching networks were designed for two different size GaN HEMT devices. One of these examples was implemented and characterized, and a drain efficiency from 52% to 70% and an output power between 40 dBm and 42.5 dBm were obtained, over 67% of the 5G sub-6-GHz band (i.e., 0.1 to 4 GHz). The aforementioned results, to the best of the authors’ knowledge, represent the state of the art in broadband power amplifiers. Full article
(This article belongs to the Special Issue Feature Papers of Micromachines in "Materials and Processing" 2022)
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11 pages, 3855 KiB  
Article
AMOLED Pixel Circuit Using LTPO Technology Supporting Variable Frame Rate from 1 to 120 Hz for Portable Displays
by Ching-Lin Fan, Chun-Yuan Chen, Shih-Yang Liu and Wei-Yu Lin
Micromachines 2022, 13(9), 1505; https://doi.org/10.3390/mi13091505 - 10 Sep 2022
Cited by 1 | Viewed by 4129
Abstract
This paper proposes a new 6T1C pixel circuit based on low-temperature polycrystalline oxide (LTPO) technology for portable active-matrix organic light-emitting diode (AMOLED) displays with variable refresh rates ranging from 1 to 120 Hz. The proposed circuit has a simple structure and is based [...] Read more.
This paper proposes a new 6T1C pixel circuit based on low-temperature polycrystalline oxide (LTPO) technology for portable active-matrix organic light-emitting diode (AMOLED) displays with variable refresh rates ranging from 1 to 120 Hz. The proposed circuit has a simple structure and is based on the design of sharing lines of switch-controlling signals. It also provides low-voltage driving and immunity to OLED degeneration issues. The calculation and analysis of programming time are discussed, and the optimal storage capacitor for the proposed circuit’s high-speed driving is selected. The results of the simulation reveal that threshold voltage variations in driving thin-film transistors of ±0.33 V can be well sensed and compensated with a 1.8% average shift of OLED currents in high-frame-rate operation (120 Hz), while the maximum variation in OLED currents within all gray levels is only 3.56 nA in low-frame-rate operation (1 Hz). As a result, the proposed 6T1C pixel circuit is a good candidate for use in portable AMOLED displays. Full article
(This article belongs to the Special Issue Feature Papers of Micromachines in "Materials and Processing" 2022)
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13 pages, 3894 KiB  
Article
Tunable, Low–Cost, Multi–Channel, Broadband Liquid Crystal Shutter for Fluorescence Imaging in Widefield Microscopy
by Yan Gong, Bo Li, Cheng-You Yao, Weiyang Yang, Qi Hua Fan, Zhen Qiu and Wen Li
Micromachines 2022, 13(8), 1310; https://doi.org/10.3390/mi13081310 - 13 Aug 2022
Viewed by 1458
Abstract
Bistable liquid crystal (LC) shutters have attracted much interest due to their low energy consumption and fast response time. In this paper, we demonstrate an electrically tunable/switchable biostable LC light shutter in biological optics through a three–step easy–assembly, inexpensive, multi–channel shutter. The liquid [...] Read more.
Bistable liquid crystal (LC) shutters have attracted much interest due to their low energy consumption and fast response time. In this paper, we demonstrate an electrically tunable/switchable biostable LC light shutter in biological optics through a three–step easy–assembly, inexpensive, multi–channel shutter. The liquid crystal exhibits tunable transparency (100% to 10% compared to the initial light intensity) under different voltages (0 V to 90 V), indicating its tunable potential. By using biomedical images, the response time, resolution, and light intensity changes of the LC under different voltages in three common fluorescence wavelengths are displayed intuitively. Particularly, the shutter’s performance in tumor images under the near–infrared band shows its application potential in biomedical imaging fields. Full article
(This article belongs to the Special Issue Feature Papers of Micromachines in "Materials and Processing" 2022)
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13 pages, 4422 KiB  
Article
Investigation of Solvent-Assisted In-Mold Bonding of Cyclic Olefin Copolymer (COC) Microfluidic Chips
by Qiang Li, Bingyan Jiang, Xianglin Li and Mingyong Zhou
Micromachines 2022, 13(6), 965; https://doi.org/10.3390/mi13060965 - 18 Jun 2022
Cited by 2 | Viewed by 1811
Abstract
The bonding of microfluidic chips is an essential process to enclose microchannels or microchambers in a lab-on-a-chip. In order to improve the bonding quality while reducing the fabrication time, a solvent-assisted bonding strategy was proposed to seal the microchannels immediately after the cover [...] Read more.
The bonding of microfluidic chips is an essential process to enclose microchannels or microchambers in a lab-on-a-chip. In order to improve the bonding quality while reducing the fabrication time, a solvent-assisted bonding strategy was proposed to seal the microchannels immediately after the cover sheet and substrate chip was injection molded in a single mold. Proper organic solvents were selected and the influences of solvent ratios on the surface roughness, microchannel morphology, and contact angle of microfluidic chips were investigated. When the solvent bonding was integrated in the mold, the influences of solvent volume fraction, solvent dosage, bonding pressure, and bonding time on the bonding quality were analyzed. Results show that the solvent cyclohexane needs to be mixed with isopropanol to reduce the dissolution effect. Solvent treatment is suggested to be performed on the cover sheet with a cyclohexane volume fraction of 70% and a dose of 1.5 mL, a bonding pressure of 2 MPa, and a bonding time of 240 s. The bonding strength reaches 913 kPa with the optimized parameters, while the microchannel deformation was controlled below 8%. Full article
(This article belongs to the Special Issue Feature Papers of Micromachines in "Materials and Processing" 2022)
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22 pages, 12670 KiB  
Article
Robust Touch Screen Readout System to Display Noise Using Multireference Differential Sensing Scheme for Flexible AMOLED Display
by Junmin Lee, Hyoyoung Kim, Juwon Ham and Seunghoon Ko
Micromachines 2022, 13(6), 942; https://doi.org/10.3390/mi13060942 - 14 Jun 2022
Cited by 2 | Viewed by 1950
Abstract
This paper presents a front-end architecture for touch screen panel (TSP) readout in a TSP-integrated, ultrathin flexible display to mitigate severe display noise interference, which is an uncommon mode caused by the large panel load of the TSP in the flexible display. The [...] Read more.
This paper presents a front-end architecture for touch screen panel (TSP) readout in a TSP-integrated, ultrathin flexible display to mitigate severe display noise interference, which is an uncommon mode caused by the large panel load of the TSP in the flexible display. The differential sensing method with multireference TSP channels minimized an imbalance of the phase and amplitude of the coupled-display noise interference. In addition, cascaded time-discrete bandpass sampling was employed to enhance the touch sensitivity in the sensing block. Moreover, a rated front-end block could be reconfigured to a differential or single-ended sensing structure, which reused the prefilter capacitors in the differential sensing for offset cancellation in reference capacitance sensing. To further improve the sensitivity, programmable postfiltering was employed on the reference TSP channels. Subsequently, the proposed front-end was implemented in a 350 nm process, wherein it achieved a SNR of 50.5 dB with a scan rate of 200 Hz and attenuated aggravated display noise interference by more than 6.84 dB as compared to the conventional differential sensing method. The designed chip occupied an area of 4.8 mm2 and consumed 17.6 mW from a 3 V supply. Full article
(This article belongs to the Special Issue Feature Papers of Micromachines in "Materials and Processing" 2022)
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17 pages, 6509 KiB  
Article
Interlacing Infills for Multi-Material Fused Filament Fabrication Using Layered Depth Material Images
by Irfan Mustafa and Tsz Ho Kwok
Micromachines 2022, 13(5), 773; https://doi.org/10.3390/mi13050773 - 14 May 2022
Cited by 1 | Viewed by 1828
Abstract
One major concern regarding multi-material additive manufacturing (MMAM) is the strength at the interface between materials. Based on the observation of how nature puts materials together, this paper hypothesizes that overlapping and interlacing materials with each other enhance the interface bonding strength. To [...] Read more.
One major concern regarding multi-material additive manufacturing (MMAM) is the strength at the interface between materials. Based on the observation of how nature puts materials together, this paper hypothesizes that overlapping and interlacing materials with each other enhance the interface bonding strength. To test this hypothesis, this research develops a new slicing framework that can efficiently identify the multi-material regions and develop interlaced infills. Based on a ray-tracing technology, we develop layered depth material images (LDMI) to process the material information of digital models for toolpath planning. Each sample point in the LDMI has an associated material and geometric properties that are used to recover the material distribution in each slice. With this material distribution, this work generates an interlocking joint and an interlacing infill in the regions with multiple materials. The experiments include comparisons between similar materials and different materials. Tensile tests have shown that our proposed infill outperforms the interlocking joint in all cases. Fractures occur even outside the interlacing area, meaning that the joint is at least as strong as the materials. The experimental results verify the enhancement of interface strength by overlapping and interlacing materials. In addition, existing computational tools have limitations in full use of material information. To the best of our knowledge, this is the first time a slicer can process overlapped material regions and create interlacing infills. The interlacing infills improve the bonding strength, making the interface no longer the weakest area. This enables MMAM to fabricate truly functional parts. In addition, the new LDMI framework has rich information on geometry and material, and it allows future research in multi-material modeling. Full article
(This article belongs to the Special Issue Feature Papers of Micromachines in "Materials and Processing" 2022)
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12 pages, 3471 KiB  
Article
Ultra-Broadband, Polarization-Irrelevant Near-Perfect Absorber Based on Composite Structure
by Yanlong Meng, Jinghao Wu, Simeng Liu, Yi Li, Bo Hu and Shangzhong Jin
Micromachines 2022, 13(2), 267; https://doi.org/10.3390/mi13020267 - 06 Feb 2022
Cited by 1 | Viewed by 1364
Abstract
This paper proposes a near-perfect absorption device based on a cross-shaped titanium nanostructure and a multilayered structure. The multilayered bottom structure consists of alternately SiO2 and Ti. The whole device is put on a TiN substrate. The coupling between cross-shaped titanium nanostructures, [...] Read more.
This paper proposes a near-perfect absorption device based on a cross-shaped titanium nanostructure and a multilayered structure. The multilayered bottom structure consists of alternately SiO2 and Ti. The whole device is put on a TiN substrate. The coupling between cross-shaped titanium nanostructures, and that between the cross-shaped titanium nanostructure and bottom multilayer, can further enhance the absorption at some wavelength where most of the energy is reflected or passes through in the device with a single structure. According to the simulation results, the device presents a nearly perfect absorption in a wavelength range from 300 nm to 2000 nm. The average absorptance in the wavelength range from 500 nm to 1400 nm exceeds 96%. This paper also provides a new idea for realizing perfect absorption, which is extensively used in sensing, controllable thermal emission, solar energy harvesting solar thermo-photovoltaic devices, and optoelectronic metrology. Full article
(This article belongs to the Special Issue Feature Papers of Micromachines in "Materials and Processing" 2022)
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Review

Jump to: Research

16 pages, 2792 KiB  
Review
Optimized 3D Bioprinting Technology Based on Machine Learning: A Review of Recent Trends and Advances
by Jaemyung Shin, Yoonjung Lee, Zhangkang Li, Jinguang Hu, Simon S. Park and Keekyoung Kim
Micromachines 2022, 13(3), 363; https://doi.org/10.3390/mi13030363 - 25 Feb 2022
Cited by 26 | Viewed by 8417
Abstract
The need for organ transplants has risen, but the number of available organ donations for transplants has stagnated worldwide. Regenerative medicine has been developed to make natural organs or tissue-like structures with biocompatible materials and solve the donor shortage problem. Using biomaterials and [...] Read more.
The need for organ transplants has risen, but the number of available organ donations for transplants has stagnated worldwide. Regenerative medicine has been developed to make natural organs or tissue-like structures with biocompatible materials and solve the donor shortage problem. Using biomaterials and embedded cells, a bioprinter enables the fabrication of complex and functional three-dimensional (3D) structures of the organs or tissues for regenerative medicine. Moreover, conventional surgical 3D models are made of rigid plastic or rubbers, preventing surgeons from interacting with real organ or tissue-like models. Thus, finding suitable biomaterials and printing methods will accelerate the printing of sophisticated organ structures and the development of realistic models to refine surgical techniques and tools before the surgery. In addition, printing parameters (e.g., printing speed, dispensing pressure, and nozzle diameter) considered in the bioprinting process should be optimized. Therefore, machine learning (ML) technology can be a powerful tool to optimize the numerous bioprinting parameters. Overall, this review paper is focused on various ideas on the ML applications of 3D printing and bioprinting to optimize parameters and procedures. Full article
(This article belongs to the Special Issue Feature Papers of Micromachines in "Materials and Processing" 2022)
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40 pages, 9254 KiB  
Review
Engineering Biological Tissues from the Bottom-Up: Recent Advances and Future Prospects
by Xiaowen Wang, Zhen Wang, Wenya Zhai, Fengyun Wang, Zhixing Ge, Haibo Yu and Wenguang Yang
Micromachines 2022, 13(1), 75; https://doi.org/10.3390/mi13010075 - 31 Dec 2021
Cited by 4 | Viewed by 3399
Abstract
Tissue engineering provides a powerful solution for current organ shortages, and researchers have cultured blood vessels, heart tissues, and bone tissues in vitro. However, traditional top-down tissue engineering has suffered two challenges: vascularization and reconfigurability of functional units. With the continuous development of [...] Read more.
Tissue engineering provides a powerful solution for current organ shortages, and researchers have cultured blood vessels, heart tissues, and bone tissues in vitro. However, traditional top-down tissue engineering has suffered two challenges: vascularization and reconfigurability of functional units. With the continuous development of micro-nano technology and biomaterial technology, bottom-up tissue engineering as a promising approach for organ and tissue modular reconstruction has gradually developed. In this article, relevant advances in living blocks fabrication and assembly techniques for creation of higher-order bioarchitectures are described. After a critical overview of this technology, a discussion of practical challenges is provided, and future development prospects are proposed. Full article
(This article belongs to the Special Issue Feature Papers of Micromachines in "Materials and Processing" 2022)
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