MicromachinesPub Date : 2025-08-27DOI: 10.3390/mi16090984
Pinqing Wang, Zhe Chen, Yubin Guo, Yue Qi, Peng Yang
{"title":"A Wideband D-Band Frequency Sextupler Chain with High Harmonic Rejection in 100 nm GaAs pHEMT Technology.","authors":"Pinqing Wang, Zhe Chen, Yubin Guo, Yue Qi, Peng Yang","doi":"10.3390/mi16090984","DOIUrl":"10.3390/mi16090984","url":null,"abstract":"<p><p>This paper presents a wideband D-band frequency sextupler chain implemented in a 100 nm GaAs pHEMT process. The proposed circuit comprises an input-stage frequency tripler, an inter-stage harmonic-rejection power amplifier, and an output-stage frequency doubler. The tripler adopts a balanced topology, which effectively suppresses the fundamental frequency component. The inter-stage power amplifier not only delivers sufficient drive power to the doubler but also enhances suppression of undesired harmonics. The output doubler employs a single-balanced configuration to suppress odd-order harmonics while extracting the second harmonic. The measured peak output power of the sextupler chain is 2.33 dBm, corresponding to an input power of 2 dBm, resulting in a conversion gain of 0.33 dB. The 3 dB output bandwidth spans from 126.3 to 152.7 GHz, corresponding to a relative bandwidth of 18.9%. Owing to the balanced multiplier topology and harmonic-rejection PA, the 5th and 7th harmonics are suppressed by more than 20 dBc. The combination of high output power, wide operating bandwidth, and excellent harmonic suppression makes the design well suited for wideband D-band signal generation in diverse applications.</p>","PeriodicalId":18508,"journal":{"name":"Micromachines","volume":"16 9","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12472008/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145175831","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":"Rigid-Flexible Neural Optrode with Anti-Bending Waveguides and Locally Soft Microelectrodes for Multifunctional Biocompatible Neural Regulation.","authors":"Minghao Wang, Chaojie Zhou, Siyan Shang, Hao Jiang, Wenhao Wang, Xinhua Zhou, Wenbin Zhang, Xinyi Wang, Minyi Jin, Tiling Hu, Longchun Wang, Bowen Ji","doi":"10.3390/mi16090983","DOIUrl":"10.3390/mi16090983","url":null,"abstract":"<p><p>This study proposes a rigid-flexible neural optrode integrated with anti-bending SU-8 optical waveguides and locally soft peptide-functionalized microelectrodes to address the challenges of precise implantation and long-term biocompatibility in traditional neural interfaces. Fabricated via microelectromechanical systems (MEMS) technology, the optrode features a PBK/PPS/(PHE)<sub>2</sub> trilayer electrochemical modification that suppresses photoelectrochemical (PEC) noise by 63% and enhances charge storage capacity by 51 times. A polyethylene glycol (PEG)-enabled temporary rigid layer ensures precise implantation while allowing post-implantation restoration of flexibility and enabling positioning adjustment. In vitro tests demonstrate efficient light transmission through SU-8 waveguides in agar gel and a 63% reduction in PEC noise peaks. Biocompatibility analysis reveals that peptide-coated PI substrates improve cell viability by 32.5-37.1% compared to rigid silicon controls. In vivo validation in crucian carp midbrain successfully records local field potential (LFP) signals (60-80 μV), thereby confirming the optrode's sensitivity and stability. This design provides a low-damage and high-resolution tool for neural circuit analysis. It also lays a technical foundation for future applications in monitoring neuronal activity and researching neurodegenerative diseases with high spatiotemporal resolution.</p>","PeriodicalId":18508,"journal":{"name":"Micromachines","volume":"16 9","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12471448/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145176390","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":"Fabricating High Aspect Ratio Amorphous Alloys Microgrooves by Using Periodically Thinning Jet Electrochemical Milling Method.","authors":"Yahui Li, Pingmei Ming, Dongdong Li, Rongbo Zhao, Shen Niu","doi":"10.3390/mi16090979","DOIUrl":"10.3390/mi16090979","url":null,"abstract":"<p><p>Jet electrochemical milling (JECM) offers significant advantages for fabricating fine grooves and slits in thin-walled, low-rigidity, and heat-sensitive metallic materials, such as amorphous alloys, owing to its operational flexibility, lack of material constraints, and superior surface quality. Nevertheless, conventional JECM techniques for groove machining encounter limitations including excessive overcut, restricted ability to produce microstructures with high depth-to-width ratios, and reduced machining accuracy. To address these issues, this study proposes an innovative approach termed the periodically thinning jet electrochemical milling (PT-JECM) method. This method involves initially generating a shallow microgroove through a single pass using the original nozzle diameter, followed by successive milling passes with progressively smaller nozzle diameters based on the preformed groove. Comparative analysis with traditional JECM methods reveals that this strategy significantly improves the etching factor from 1.896 to 4.318, corresponding to a 128% enhancement. Furthermore, it markedly decreases the slot width increase from 275 μm to 1 μm and improves the aspect ratio from 0.51 to 0.83, representing a 63% increase, enabling the precision machining of large aspect ratio holes and slot structures.</p>","PeriodicalId":18508,"journal":{"name":"Micromachines","volume":"16 9","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12472117/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145176393","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":"The Cutting Edge Geometric Optimization of the PCBN Tool for the Machining of Cast Iron.","authors":"Xian Wu, Zhiqin Su, Chao Zhang, Xuefeng Zhao, Hongfei Yao, Feng Jiang","doi":"10.3390/mi16090978","DOIUrl":"10.3390/mi16090978","url":null,"abstract":"<p><p>The turning process is the main machining task in brake disc production, and the PCBN tool is the most suitable type of cutting tools in the machining of brake discs made of cast iron. The edge geometric optimization of the PCBN tool is the key factor to obtain a better tool performance. In this paper, the cutting simulation for the machining of cast iron with PCBN tool of grade HNMN120712 was established, which exhibits a simulation error lower than 10.8%. The optimal turning parameters were obtained by the equal material removal rate method. The edge geometric parameters were optimized in two stages: firstly, the optimal edge radius was obtained as 30 μm by the comprehensive normalization analysis of the cutting temperature and stress, and then, the chamfer width and angle were further optimized to 0.1 mm and 15°. At finally, the optimized PCBN tool was prepared and tested in the machining of brake discs; the results indicate that the designed tool exhibits an excellent tool performance with 3.4 times the tool life of the conventional tool.</p>","PeriodicalId":18508,"journal":{"name":"Micromachines","volume":"16 9","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12471497/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145176537","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}
MicromachinesPub Date : 2025-08-26DOI: 10.3390/mi16090980
Kai Werum, Wolfgang Eberhardt, Dieter Reenaers, Thomas Mager, Mika Endl, André Zimmermann, Wim Deferme
{"title":"Assembly and Interconnection Technologies for 3D Plastic Circuit Carriers: An Overview of Technologies, Materials, and Applications.","authors":"Kai Werum, Wolfgang Eberhardt, Dieter Reenaers, Thomas Mager, Mika Endl, André Zimmermann, Wim Deferme","doi":"10.3390/mi16090980","DOIUrl":"10.3390/mi16090980","url":null,"abstract":"<p><p>This paper aims to present an overview of the state-of-the-art materials and technologies that can be used to create electronic circuits on 3D plastic carriers also known as 3D electronics. Strategies for print-based and laser-based 3D electronics will be discussed as well as the techniques to apply the circuit carrier and the way interconnection technology can be used to combine electronic components on top of the circuit carrier. A basic explanation of the functional principles, materials, and applications is given for different substrate and interconnection technologies. The aim is to make it easier to compare different technologies and its required materials to make the right decisions on what technology is best suited for the job. For this purpose, comparison tables for 3D plastic circuit carrier technologies and substrate materials considering their temperature stability were created. It can be concluded that there are a lot of influencing factors that determine which technologies are best suited for application. The most important factors are the 3D complexity and the field of application, the required structure size of the circuit, and the required production quantity.</p>","PeriodicalId":18508,"journal":{"name":"Micromachines","volume":"16 9","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12471658/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145176263","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}
MicromachinesPub Date : 2025-08-26DOI: 10.3390/mi16090982
Qiang Liu, Xiping He, Weiguo Wang, Yanning Yang
{"title":"Study on the Loss and Characteristics of Giant Magnetostrictive Transducers.","authors":"Qiang Liu, Xiping He, Weiguo Wang, Yanning Yang","doi":"10.3390/mi16090982","DOIUrl":"10.3390/mi16090982","url":null,"abstract":"<p><p>The purpose of this work is to enable the giant magnetostrictive transducer to work efficiently. In this work, the finite element method was used to carry out a dynamic analysis and magnetic analysis of the transducers of GMM rods with different structures, and the transducers of three structural rods were developed, and the output amplitude and impedance of the three transducers were experimentally tested. The results show that the stress of the rod near the end of the tail mass was larger than that near the end of the head mass. The eddy current and hysteresis losses of the transducer were mainly concentrated on the outer diameter surface of the rod, near the cutting slit, and near the connection between the slices. In addition, there is a certain amount of eddy current loss on the magnetic conductor, permanent magnet, and coil. In the transducer with the untreated rod, the resistance and inductance were the smallest. The inductance of the transducers with the sliced rods were greater than those in the transducers with the slit rods. The transducer with the untreated rod has the highest resonant frequency and the smallest output amplitude, the resonant frequency of the transducers with the sliced rods was lower than that of the transducers with the slit rods, while the output amplitude of the transducers with the sliced rods was greater than that of the transducers with the slit rods. The simulated values of the resonant frequency, output amplitude, resistance, and inductance of the transducers of the three structural rods were basically consistent with the tested values.</p>","PeriodicalId":18508,"journal":{"name":"Micromachines","volume":"16 9","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12471911/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145176388","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}
MicromachinesPub Date : 2025-08-26DOI: 10.3390/mi16090977
Abdurrashid Hassan Shuaibu, Almur A S Rabih, Yves Blaquière, Frederic Nabki
{"title":"Push-Push Electrothermal MEMS Actuators with Si-to-Si Contact for DC Power Switching Applications.","authors":"Abdurrashid Hassan Shuaibu, Almur A S Rabih, Yves Blaquière, Frederic Nabki","doi":"10.3390/mi16090977","DOIUrl":"10.3390/mi16090977","url":null,"abstract":"<p><p>MEMS switches offer great advantages over solid-state and conventional electromechanical switches, including a compact size and high isolation. This paper presents a novel silicon-to-silicon (Si-to-Si) MEMS switch featuring two suspended actuated platforms for DC power switching applications. The proposed design uniquely incorporates dual suspended chevron actuators, enabling bidirectional actuation, enhancing force generation, and improving overall switching performance. Leveraging the robustness of silicon, this Si-to-Si contact switch aims to enhance the reliability of MEMS-based DC power switches. Testing of a fabricated device in the PiezoMUMPs process demonstrated that a 2 μm initial contact gap closes at 1.1 <i>V</i><sub>DC</sub>, with a total actuation power of 246 mW. The switch exhibits a linear voltage-current response up to 5 mA of switching current and achieves a minimum contact resistance of ~294 ± 2 Ω, one of the lowest reported for Si-to-Si contacts. This low contact resistance is attributed to the suspended contact platforms, which mitigate misalignment. The measured response time was 4 ms for turn-on and 2.5 ms for turn-off. This switch withstood a breakdown voltage of up to 376 V across the 2 µm contact gap. Moreover, the 200 nm thick oxide layer separating the actuation and signal lines exhibited breakdown at 183 V. These findings highlight the potential of the switch for high-voltage applications and pave the way for further enhancements to improve its reliability in harsh environments.</p>","PeriodicalId":18508,"journal":{"name":"Micromachines","volume":"16 9","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12471420/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145176327","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":"Material Removal on Hydrogen-Terminated Diamond Surface via AFM Tip-Based Local Anodic Oxidation.","authors":"Jinyan Tang, Zhong-Hao Cao, Zhongwei Li, Yuan-Liu Chen","doi":"10.3390/mi16090981","DOIUrl":"10.3390/mi16090981","url":null,"abstract":"<p><p>Diamond is a promising next-generation semiconductor material, offering a wider band gap, higher electron mobility, and superior thermal conductivity compared with silicon. However, its exceptional hardness makes it challenging to fabricate. In this study, we demonstrate a novel approach to realize material removal on hydrogen-terminated diamond surfaces by atomic force microscope (AFM) tip-based local anodic oxidation. By adjusting both the applied voltage and hydrogen plasma etching parameters, the material is removed over an area larger than the AFM tip size. Notably, the hardness of the material surrounding the removal zone is significantly reduced, enabling it to be scratched with a silicon tip. These findings open a promising pathway for improving the machinability of diamonds in future device applications.</p>","PeriodicalId":18508,"journal":{"name":"Micromachines","volume":"16 9","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12471924/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145176522","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}
MicromachinesPub Date : 2025-08-25DOI: 10.3390/mi16090976
Haipeng Yan, Haining Zhang, Siyuan Cao, Chao Wang
{"title":"Study on Nano-Grinding Characteristics and Formation Mechanism of Subsurface Damage in Monocrystalline Silicon.","authors":"Haipeng Yan, Haining Zhang, Siyuan Cao, Chao Wang","doi":"10.3390/mi16090976","DOIUrl":"10.3390/mi16090976","url":null,"abstract":"<p><p>Monocrystalline silicon is an excellent semiconductor material for integrated circuits. Its surface quality has an enormous effect on its service life. The surfaces are formed by ultra-precision machining using nano-grinding, one of the technologies that can achieve surface roughness at the nano- or sub-nano-scale. Therefore, subsurface damage of monocrystalline silicon in nano-grinding was studied by establishing a molecular dynamics simulation model, and the impact of machining parameters on the force-thermal behavior was analyzed. The results reveal that the mechanism of subsurface damage is mainly structural phase transformation and amorphization. In nano-grinding of monocrystalline silicon, the tangential grinding force has a relatively major role in material removal. With increasing grinding depth and grinding speed, the grinding heat rises, and a certain degree of high temperature strengthens the toughness of the material, improving the subsurface quality of monocrystalline silicon. Therefore, subsurface damage in monocrystalline silicon can be controlled by reducing the grinding depth and increasing the grinding speed.</p>","PeriodicalId":18508,"journal":{"name":"Micromachines","volume":"16 9","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12471329/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145176424","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":"Study of the Equivalent Stiffness of a Non-Contact Piezoelectric Actuator's Micro-Displacement Amplification Mechanism.","authors":"Huaiyong Li, Dongya Zhang, Yusheng Lin, Yue Yang, Zhiwei Shi, Chong Li","doi":"10.3390/mi16090974","DOIUrl":"10.3390/mi16090974","url":null,"abstract":"<p><p>To address the issues of mechanical wear and limited service life in conventional contact piezoelectric actuators, this study proposes a non-contact piezoelectric actuator employing compressed air for energy transmission; we elucidate its structure and operating principle. The working performance of the actuator is significantly affected by the amplification performance of its micro-displacement amplification mechanism, which itself is closely dependent on the mechanism's stiffness. Mathematical models for both the filleted straight-beam flexure hinge and the micro-displacement amplification mechanism are established. Analytical equations for calculating the equivalent stiffness of the hinge and the mechanism are derived. The variations in the hinge's bending stiffness and tensile stiffness, as well as the mechanism's equivalent stiffness with key structural parameters, are investigated. The stress distribution of the micro-displacement amplification mechanism is analyzed to evaluate the rationality and reliability of its structural design. A prototype is fabricated and equivalent stiffness tests are conducted. The theoretical calculation is basically consistent with the experimental results, verifying the accuracy of the stiffness model. The results show that flexure hinge tensile stiffness significantly exceeds the bending stiffness, permitting the simplification of the hinge stiffness model. Hinge minimum thickness and beam length critically affect mechanism stiffness; reducing thickness or increasing beam length lowers stiffness, boosting displacement amplification.</p>","PeriodicalId":18508,"journal":{"name":"Micromachines","volume":"16 9","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12471884/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145176433","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}