Micromachines最新文献

{"title":"Application of Generalized Finite Difference Method for Nonlinear Analysis of the Electrothermal Micro-Actuator.","authors":"Hao Chen, Xiaoyu Kong, Xiangdong Sun, Mengxu Chen, Haiyang Yuan","doi":"10.3390/mi16030325","DOIUrl":"10.3390/mi16030325","url":null,"abstract":"<p><p>In this work, the generalized finite difference method (GFDM), a popular meshless numerical method, is employed for predicting the thermal and mechanical behavior of an electrothermal micro-actuator. Based on the concept of GFDM and discretization on the computational domain, the discrete forms of the thermal and mechanical governing equations are derived, respectively. With the help of the incremental load method, the discrete form from the electrothermal analysis is solved precisely and the temperature distribution is obtained. Meanwhile, combining this approach with the discrete control equation derived from the natural boundary condition, its displacement is also evaluated. The convergence of the temperature by different iterative methods is tested and compared. The computational stability and efficiency (CPU time) in these two analyses are also given in this study. To further investigate the accuracy of the solutions, experiments to capture temperature and FEM analysis are conducted. Regardless of the imperfect boundary condition, the temperature distribution calculated by the GFDM shows great agreement with that obtained by experiment and FEM. A similar phenomenon can be also found in the comparison between the displacements evaluated by the GFDM and FEM, respectively.</p>","PeriodicalId":18508,"journal":{"name":"Micromachines","volume":"16 3","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11946515/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143720051","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluation of Perfusion Cell Culture Conditions in a Double-Layered Microphysiological System Using AI-Assisted Morphological Analysis.","authors":"Naokata Kutsuzawa, Tomomi Goto, Hiroko Nakamura, Miwa Maeda, Masaki Kinehara, Junko Sakagami, Hiroshi Kimura","doi":"10.3390/mi16030327","DOIUrl":"10.3390/mi16030327","url":null,"abstract":"<p><p>In recent years, microphysiological systems (MPS) using microfluidic technology as a new in vitro experimental system have shown promise as an alternative to animal experiments in the development of drugs, especially in the field of drug discovery, and some reports have indicated that MPS experiments have the potential to be a valuable tool to obtain outcomes comparable to those of animal experiments. We have commercialized the Fluid3D-X^®, a double-layer microfluidic chip made of polyethylene terephthalate (PET), under the Japan Agency for Medical Research and Development (AMED) MPS development research project and have applied it to various organ models. When intestinal epithelial cells, Caco-2, were cultured using Fluid3D-X^® and a peristaltic pump, villi-like structures were formed in the microchannels. Still, the degree of formation differed between the upstream and downstream sides. To examine the consideration points regarding the effects of the nutrient and oxygen supply by the chip material and the medium perfusion rate and direction on cells in the widely used double-layer microfluidic chip and to demonstrate the usefulness of a new imaging evaluation method using artificial intelligence technology as an assistive tool for the morphological evaluation of cells, the cell morphology in the channels was quantified and evaluated using the Nikon NIS.ai and microscopic observation. Villi-like structures were predominant upstream of the top channel, independent of the medium perfusion on the bottom channel, and those structures downstream developed with an increased flow rate. Additionally, compared to the Fluid3D-X^®, the chip made of PDMS showed almost uniform villi-like sterilization in the channel. The result indicates that the environment within the microchannels differs because the amount of nutrients and oxygen supply varies depending on the medium's perfusion and the material of the chips. As the amount of oxygen and nutrients required by different cell types differs, it is necessary to study the optimization of culture conditions according to the characteristics of the cells handled. It was also demonstrated that the AI-based image analysis method is helpful as a quantification method for the differences in cell morphology in the microchannel observed under a microscope.</p>","PeriodicalId":18508,"journal":{"name":"Micromachines","volume":"16 3","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11945015/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143720281","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact of Bonding Pressure on the Reactive Bonding of LTCC Substrates.","authors":"Erik Wiss, Nesrine Jaziri, Jens Müller, Steffen Wiese","doi":"10.3390/mi16030321","DOIUrl":"10.3390/mi16030321","url":null,"abstract":"<p><p>Reactive bonding can overcome the issues associated with conventional soldering processes, such as potential damage to heat-sensitive components and the creation of thermomechanical stress due to differing coefficients of thermal expansion. The risk of such damage can be reduced by using localized heat sources like reactive multilayer systems (RMS), which is already a well-established option in the field of silicon or metal bonding. Adapting this process to other materials, such as low temperature co-fired ceramics (LTCC), is difficult due to their differing properties, but it would open new technological possibilities. One aspect that significantly affects the quality of the bonding joints is the pressure applied during the bonding process. To investigate its influence more closely, various LTCC samples were manufactured, and cross-sections were prepared. The microscopical analysis reveals that there is an optimum range for the bonding pressure. While too little pressure results in the formation of lots of voids and gaps, most likely in poor mechanical and electrical properties, too high pressure seems to cause a detachment of the metallization from the base material.</p>","PeriodicalId":18508,"journal":{"name":"Micromachines","volume":"16 3","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11946838/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143719751","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development of an Easy-to-Fabricate Microdevice for Three-Dimensional Culture and Its Application to Glomerular Endothelial Cell Culture.","authors":"Miyu Yamazaki, Yasuko Kobayashi, Kiichi Sato","doi":"10.3390/mi16030324","DOIUrl":"10.3390/mi16030324","url":null,"abstract":"<p><p>The development of an organ-on-a-chip to reproduce organ functions requires the incorporation of a vascular network within the tissue to transport the necessary nutrients. Tissues thicker than 200 µm cannot survive without a capillary network, necessitating the construction of a vascular network exceeding that thickness. Therefore, we focused on the development of an inexpensive and easy-to-fabricate device for thick three-dimensional(3D)-cultured tissues. This device does not have a conventional pillar array structure, and the nutrient supply to the cells from adjacent media channels is not obstructed. Additionally, this device does not require expensive soft lithography equipment or a high-precision 3D printer to fabricate the mold. Human glomerular endothelial cells and human dermal fibroblasts were co-cultured using this device, and a 3D network of vascular endothelial cells (200 µm thick) was successfully constructed. The results of this study are expected to contribute not only to the study of angiogenesis, but also to the development of 3D tissue models that require the incorporation of capillary networks as well as the development of vascularized organ-on-a-chip and disease models for drug screening.</p>","PeriodicalId":18508,"journal":{"name":"Micromachines","volume":"16 3","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11944802/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143720215","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Design, Analysis, and Manufacturing of Diffractive Achromatic Optical Systems.","authors":"Yidi Zheng, Junfeng Du, Boping Lei, Jiang Bian, Lihua Wang, Bin Fan","doi":"10.3390/mi16030322","DOIUrl":"10.3390/mi16030322","url":null,"abstract":"<p><p>The increasing resolution requirements of imaging optical systems must be satisfied by expanding the aperture of the optical system according to Rayleigh's criterion, and larger apertures of conventional refractive/reflective optics place a greater demand on manufacturing and transportation. Diffractive optics are applied to imaging optics to achieve lightweight design, but the image quality suffers due to their strong negative properties. Therefore, a wide-band imaging system based on the Schupmann achromatic model is proposed in this paper to solve the above problem, and the achromatic performance of the system is guaranteed by the Schupmann achromatic model. The aperture of the relay lens is reduced, since using harmonic diffractive optics as the primary lens results in a much more compact focus compared to the diffractive optics in the same wavelength band. This allows for the lightweight design of the optical system. An 80 mm aperture diffractive optical system covering the 400-900 nm band was designed and fabricated to verify the above theory. The actual resolution of the optical system was 76.196 lp/mm, and the achromatic task was accomplished. The design and experimentation of the wide-band achromatic imaging optical system confirms that the proposed theory is correct, and lays the foundation for the further application of large aperture diffractive telescopes.</p>","PeriodicalId":18508,"journal":{"name":"Micromachines","volume":"16 3","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11945864/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143720253","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Design of a High Coupling SAW Resonator Based on an Al/41° Y-X LiNbO₃/SiO₂/poly-Si/Si Structure for Wideband Filter.","authors":"Xiaoyu Wang, Yang Chang, Qiaozhen Zhang, Luyao Liu, Xinyi Wang, Haodong Wu","doi":"10.3390/mi16030323","DOIUrl":"10.3390/mi16030323","url":null,"abstract":"<p><p>With the rapid development of fifth-generation (5G) mobile communication technology, the performance requirements for radio frequency front-end surface acoustic wave (SAW) devices have become increasingly stringent. Surface acoustic wave devices on piezoelectric thin film-based layered structures with high electromechanical coupling coefficients and low-frequency temperature compensation characteristics have emerged as a key solution. In this work, a SAW resonator based on an Al/41° Y-X LiNbO₃/SiO₂/poly-Si/Si multi-layered structure is proposed. FEM modeling of the proposed resonator and the influences of the thicknesses of the LiNbO₃, SiO₂, and Al electrodes on performances such as the parasitic noise, bandwidth, and electromechanical coupling coefficient are analyzed. Optimal parameters for the multi-layer piezoelectric structure are identified for offering large coupling up to 24%. Based on these findings, a single-port SAW resonator with an Al/41° Y-X LiNbO₃/SiO₂/poly-Si/Si substrate structure is fabricated. The experimental results align well with the simulation results; meanwhile, the SAW filter based on the proposed resonator demonstrates that a center frequency of 2.3 GHz, a 3-dB fractional bandwidth of 23.48%, and a minimum in-band insertion loss of only 0.343 dB are simultaneously achieved. This study provides guidance for the development of multi-layer film SAW resonator-based filters with high-performance.</p>","PeriodicalId":18508,"journal":{"name":"Micromachines","volume":"16 3","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11946720/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143720155","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Review of Wafer-Level Packaging Technology for SAW and BAW Filters.","authors":"Xinyue Liu, Wenjiao Pei, Jin Zhao, Rongbin Xu, Yi Zhong, Daquan Yu","doi":"10.3390/mi16030320","DOIUrl":"10.3390/mi16030320","url":null,"abstract":"<p><p>This paper presents a comprehensive review of advancements in wafer-level packaging (WLP) technology, with a particular focus on its application in surface acoustic wave (SAW) and bulk acoustic wave (BAW) filters. As wireless communication systems continue to evolve, there is an increasing demand for higher performance and miniaturization, which has made acoustic wave devices-especially SAW and BAW filters-crucial components in the Radio Frequency (RF) front-end systems of mobile devices. This review explores key developments in WLP technology, emphasizing novel materials, innovative structures, and advanced modeling techniques that have enabled the miniaturization and enhanced functionality of these filters. Additionally, the paper discusses the role of WLP in addressing challenges related to size reduction and integration, facilitating the creation of multi-functional devices with low manufacturing costs and high precision. Finally, it highlights the opportunities and future directions of WLP technology in the context of next-generation wireless communication standards.</p>","PeriodicalId":18508,"journal":{"name":"Micromachines","volume":"16 3","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11945352/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143719748","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Electrical Characterization of Cost-Effective Screen-Printed Sensors Based on Thermoplastic Polyurethane, Polyimide, and Polyethylene Terephthalate.","authors":"Muhammad Faiz Ul Hassan, Yan Wang, Kai Yang, Yading Wen, Shichao Jin, Yi Zhang, Xiaosheng Zhang","doi":"10.3390/mi16030319","DOIUrl":"10.3390/mi16030319","url":null,"abstract":"<p><p>In recent years, the improvement in living standards and the corresponding increase in quality-of-life expectations have significantly increased the demand for advanced electronic products. This trend has generated great interest in human health monitoring and extensive research efforts. Flexible sensors in particular are being given preference because of their high extensibility, excellent biocompatibility properties, low weight, and low cost. In the present work, we took this idea further and designed flexible sensors using different substrates such as thermoplastic polyurethane (TPU), polyimide (PI), and polyethylene terephthalate (PET), fabricating them with silver paste ink using screen-printing technology. A uniform and homogeneous conductive layer was formed, which was identified through Scanning Electron Microscopy (SEM) analysis. Additionally, the width of the printed silver paste ink was approximately 100 µm. This study contributes to the design and fabrication of a new generation of flexible sensors for health monitoring. The results demonstrate that these sensors are technically possible as part of long-term wearable health-monitoring solutions for wearable health care technologies.</p>","PeriodicalId":18508,"journal":{"name":"Micromachines","volume":"16 3","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11944745/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143720276","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Differential Alternating Current Field Measurement with Deep Learning for Crack Detection and Evaluation.","authors":"Chenxu Fan, Zhenhu Jin, Jiamin Chen","doi":"10.3390/mi16030318","DOIUrl":"10.3390/mi16030318","url":null,"abstract":"<p><p>This paper introduces a novel differential TMR-ACFM probe integrated with deep learning for crack detection and evaluation. The differential design effectively mitigates the lift-off effect and external noise, thereby enhancing detection performance without increasing costs. A miniature TMR was designed and fabricated for the probe. Two TMR units were integrated in an area of 175 × 200 microns, and two dies formed the differential structure of the Wheatstone bridge. Experimental results indicate that, in comparison to conventional probes, the quality factor of the differential probe is improved by more than an order of magnitude, and the signal-to-noise ratio is enhanced by over 3 dB. Additionally, a CNN + CBAM network is developed and trained on experimental data to achieve high-precision evaluation of crack dimensions. For cracks measuring 10-30 mm in length, 2-6 mm in depth, and 0.25-1.25 mm in width, the relative errors in the predicted dimensions are 0.201%, 0.709%, and 7.224%, respectively. These results underscore the significant potential of the proposed approach for quantitative crack detection.</p>","PeriodicalId":18508,"journal":{"name":"Micromachines","volume":"16 3","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11944351/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143720270","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optoelectronic Oscillator-Based Microwave Photonic 20× Frequency Multiplier with Low Phase Noise.","authors":"Shi Jia, Qifan Zhang, Tianhao Zhang, Jinlong Yu","doi":"10.3390/mi16030317","DOIUrl":"10.3390/mi16030317","url":null,"abstract":"<p><p>This letter presents a scheme for obtaining a microwave photonic frequency multiplier with low phase noise, in which an optoelectronic oscillator (OEO) is integrated with a directly modulated laser (DML)-based injection-locking technique. The system achieves frequency multiplication factors of 10 and 20, producing 10.01009 and 19.99095 GHz microwave signals with high side-mode suppression ratios of 62.0 and 50.2 dB. The measured single-sideband phase noise values are -121.87 and -111.95 dBc/Hz@10 kHz, which are 34.9 and 31.0 dB lower than those of traditional electronic frequency multiplication methods for 1 GHz signals. By utilizing the nonlinear characteristics of the DML, combined with injection locking and the OEO system, this cost-effective scheme reduces the system complexity while enhancing the stability and phase noise performance, offering a highly efficient solution for microwave frequency multiplication.</p>","PeriodicalId":18508,"journal":{"name":"Micromachines","volume":"16 3","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11944455/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143720259","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}