Pub Date : 2024-01-09DOI: 10.1088/1361-6439/ad1c73
Ryosuke Yano, H. Kuroda
In this paper, we investigate locomotion of the artificial (robotic) swimmer by the undulating rigid flagellum, whose joins are controlled by actuators. The locomotion of the swimmer with the undulating rigid flagellum inside the two dimensional channel sandwiched by two non-slip walls is numerically analyzed using the immersed boundary Lattice Boltzmann method (IB-LBM). In order to calculate the flow field under the high Reynolds number, multi-relaxation-time (MRT) scheme is applied. Our numerical results show that the optimal Reynolds number exits to maximize locomotion distance, whereas the direction of locomotion can be reversed in the low and high Reynolds number limits.
{"title":"Artificial swim by undulating rigid flagellum with joint controllers","authors":"Ryosuke Yano, H. Kuroda","doi":"10.1088/1361-6439/ad1c73","DOIUrl":"https://doi.org/10.1088/1361-6439/ad1c73","url":null,"abstract":"\u0000 In this paper, we investigate locomotion of the artificial (robotic) swimmer by the undulating rigid flagellum, whose joins are controlled by actuators. The locomotion of the swimmer with the undulating rigid flagellum inside the two dimensional channel sandwiched by two non-slip walls is numerically analyzed using the immersed boundary Lattice Boltzmann method (IB-LBM). In order to calculate the flow field under the high Reynolds number, multi-relaxation-time (MRT) scheme is applied. Our numerical results show that the optimal Reynolds number exits to maximize locomotion distance, whereas the direction of locomotion can be reversed in the low and high Reynolds number limits.","PeriodicalId":16346,"journal":{"name":"Journal of Micromechanics and Microengineering","volume":"110 10","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139444512","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-01-09DOI: 10.1088/1361-6439/ad1c74
Ziqiang Zhao, Lin Zhao, Yun Peng
Data Access Statement: Research data supporting this publication are available from the NN repository at located at www.NNN.org/download/. Silicon carbide (SiC) is an ideal substrate for manufacturing high-power electronic devices and microwave devices, and has broad application prospects. The surface treatment of SiC wafers plays a critical role and faces challenges in the semiconductor industry. Among the multiple treatment methods, the laser-based method has gradually attracted the attention of scholars. Therefore, this research uses a femtosecond laser to ablate 4H-SiC sliced wafers and analyzes the influence of key parameters, such as laser pulse energy, defocus amount, repetition frequency, and scanning intervals, on the laser ablation depth, width, and surface morphology. Scanning electron microscopy (SEM) and laser coherence-focused microscopy were used to characterize the laser ablation surface. The results show that under a defocus amount of +6 mm, a laser pulse energy of 87.5 μJ, scanning speed of 500 mm/s, and pulse frequency of 300 kHz. The results show that the optimized surface roughness (Sa) was 0.267μm, and brittle fracture areas such as microcracks and pits on the original surface were removed. Effective removal facilitates further material surface processing, which provides valuable insights for similar researchers and benefits for the semiconductor industry. Ethical Compliance: All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards.
{"title":"Experimental study on femtosecond laser ablation of 4H-SiC substrate","authors":"Ziqiang Zhao, Lin Zhao, Yun Peng","doi":"10.1088/1361-6439/ad1c74","DOIUrl":"https://doi.org/10.1088/1361-6439/ad1c74","url":null,"abstract":"\u0000 Data Access Statement: Research data supporting this publication are available from the NN repository at located at www.NNN.org/download/. Silicon carbide (SiC) is an ideal substrate for manufacturing high-power electronic devices and microwave devices, and has broad application prospects. The surface treatment of SiC wafers plays a critical role and faces challenges in the semiconductor industry. Among the multiple treatment methods, the laser-based method has gradually attracted the attention of scholars. Therefore, this research uses a femtosecond laser to ablate 4H-SiC sliced wafers and analyzes the influence of key parameters, such as laser pulse energy, defocus amount, repetition frequency, and scanning intervals, on the laser ablation depth, width, and surface morphology. Scanning electron microscopy (SEM) and laser coherence-focused microscopy were used to characterize the laser ablation surface. The results show that under a defocus amount of +6 mm, a laser pulse energy of 87.5 μJ, scanning speed of 500 mm/s, and pulse frequency of 300 kHz. The results show that the optimized surface roughness (Sa) was 0.267μm, and brittle fracture areas such as microcracks and pits on the original surface were removed. Effective removal facilitates further material surface processing, which provides valuable insights for similar researchers and benefits for the semiconductor industry. Ethical Compliance: All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards.","PeriodicalId":16346,"journal":{"name":"Journal of Micromechanics and Microengineering","volume":"52 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139444891","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-01-09DOI: 10.1088/1361-6439/ad1c75
Yuqin Deng, Zi Ye, Zhongshan Deng, Jie Hong, Huimin Zhang, Lin Gui
This work proposes a liquid-metal-based calorimetric micro-flow sensor within a polydimethylsiloxane (PDMS) chip. It can measure the flow rate of fluid in microscale channels, with a range as low as several microliters per minute. This in-chip sensor is proposed to solve the issue of detecting the flow rate in microfluidic systems. To make the sensor compatible with PDMS microfluidic chips, low-melting-point gallium-based alloy and bismuth-based (bi-based) alloy are used to make the micro heater and bi-metal thermocouples, for these alloys can be easily injected into a PDMS chip to form electrodes. To minimize heat resistance (or temperature difference) between fluid and the detecting ends of thermocouples, these ends are directly exposed to liquid in the flow channel with the help of a special reversible bonding technology. Thermocouples are connected in parallel to improve the sensor’s response. A novel method to bond and electrically connect the sensor to a PCB (print circuit board) is also elaborated. Since the calorimetric flow sensor is sensitive to heating power, fluid temperature and environment cooling, a dimensionless parameter less independent of these factors is deduced from heat transfer theory, and this idea is used in result processing to offset the bad effect. Experiments with pure water show that this sensor can be used to detect flow rates, with a resolution up to 4 µl/min/mV and a range of 12 µl/min in this case, and that at different heating powers, the thermal potential results vary significantly whereas the dimensionless results nearly keep the same. Present work indicates that this sensor has the potential to be integrated into a PDMS microfluidic system and to provide accurate and stable results if a dimensionless method is used in data processing.
{"title":"A liquid-metal-based microscale calorimetric in-chip flow sensor for flow rate measuring","authors":"Yuqin Deng, Zi Ye, Zhongshan Deng, Jie Hong, Huimin Zhang, Lin Gui","doi":"10.1088/1361-6439/ad1c75","DOIUrl":"https://doi.org/10.1088/1361-6439/ad1c75","url":null,"abstract":"\u0000 This work proposes a liquid-metal-based calorimetric micro-flow sensor within a polydimethylsiloxane (PDMS) chip. It can measure the flow rate of fluid in microscale channels, with a range as low as several microliters per minute. This in-chip sensor is proposed to solve the issue of detecting the flow rate in microfluidic systems. To make the sensor compatible with PDMS microfluidic chips, low-melting-point gallium-based alloy and bismuth-based (bi-based) alloy are used to make the micro heater and bi-metal thermocouples, for these alloys can be easily injected into a PDMS chip to form electrodes. To minimize heat resistance (or temperature difference) between fluid and the detecting ends of thermocouples, these ends are directly exposed to liquid in the flow channel with the help of a special reversible bonding technology. Thermocouples are connected in parallel to improve the sensor’s response. A novel method to bond and electrically connect the sensor to a PCB (print circuit board) is also elaborated. Since the calorimetric flow sensor is sensitive to heating power, fluid temperature and environment cooling, a dimensionless parameter less independent of these factors is deduced from heat transfer theory, and this idea is used in result processing to offset the bad effect. Experiments with pure water show that this sensor can be used to detect flow rates, with a resolution up to 4 µl/min/mV and a range of 12 µl/min in this case, and that at different heating powers, the thermal potential results vary significantly whereas the dimensionless results nearly keep the same. Present work indicates that this sensor has the potential to be integrated into a PDMS microfluidic system and to provide accurate and stable results if a dimensionless method is used in data processing.","PeriodicalId":16346,"journal":{"name":"Journal of Micromechanics and Microengineering","volume":"20 25","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139443298","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Single crystal (SC) perovskites exhibit superior stability and optoelectronic performance compared to polycrystalline ones, offering significant potential for high-performance and low-cost photovoltaic/optoelectronic applications. However, conventional SC growth processes often require intricate cutting or transferring of SC in the manufacturing of optoelectronic devices. High-resolution, in-situ, and scalable fabrication of perovskite SC arrays remain challenging. In this work, we propose a method for in-situ deposition of cosolvent based perovskite precursor solutions using electrohydrodynamic (EHD) printing technology. The addition of a cosolvent (which exhibits good chemical compatibility with the precursor and the main solvent, accompanied by lower solubility and vapor pressure) to the mixed solution promotes early-stage supersaturation and nucleation in the solution, enabling precise control over crystal morphology, size, and positioning through in-situ EHD printing. The effect of different cosolvent ratios on SC growth and the inhibition of parasitic crystallization by altering the contact angle of substrate were investigated. Finally, the parameters for precise control of the EHD printing process were investigated, enabling the growth of SC arrays ranging from 1 to 35 μm in size. This strategy offers a direct patterning approach for SC perovskite preparation without complex temperature control or multi-step operation. The printed patterns exhibit high resolution and excellent uniformity, offering significant potential for manufacturing SC-based perovskite optoelectronic devices with precise size and positioning control.
{"title":"Precise In-situ Fabrication of Perovskite Single Crystal Arrays via Cosolvent based Electrohydrodynamic Printing","authors":"Rui Yu, Wenshuo Xie, Weili Yang, Xinrui Yang, Yongqing Duan","doi":"10.1088/1361-6439/ad1b1b","DOIUrl":"https://doi.org/10.1088/1361-6439/ad1b1b","url":null,"abstract":"\u0000 Single crystal (SC) perovskites exhibit superior stability and optoelectronic performance compared to polycrystalline ones, offering significant potential for high-performance and low-cost photovoltaic/optoelectronic applications. However, conventional SC growth processes often require intricate cutting or transferring of SC in the manufacturing of optoelectronic devices. High-resolution, in-situ, and scalable fabrication of perovskite SC arrays remain challenging. In this work, we propose a method for in-situ deposition of cosolvent based perovskite precursor solutions using electrohydrodynamic (EHD) printing technology. The addition of a cosolvent (which exhibits good chemical compatibility with the precursor and the main solvent, accompanied by lower solubility and vapor pressure) to the mixed solution promotes early-stage supersaturation and nucleation in the solution, enabling precise control over crystal morphology, size, and positioning through in-situ EHD printing. The effect of different cosolvent ratios on SC growth and the inhibition of parasitic crystallization by altering the contact angle of substrate were investigated. Finally, the parameters for precise control of the EHD printing process were investigated, enabling the growth of SC arrays ranging from 1 to 35 μm in size. This strategy offers a direct patterning approach for SC perovskite preparation without complex temperature control or multi-step operation. The printed patterns exhibit high resolution and excellent uniformity, offering significant potential for manufacturing SC-based perovskite optoelectronic devices with precise size and positioning control.","PeriodicalId":16346,"journal":{"name":"Journal of Micromechanics and Microengineering","volume":"7 10","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139385325","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-01-04DOI: 10.1088/1361-6439/ad1b1a
Manu Garg, D. S. Arya, Sushil Kumar, Khanjan Joshi, M. Yousuf, Yi-Yen Chiu, PUSHPAPRAJ SINGH
An electrostatically actuated all-metal MEMS Pirani gauge with a tunable dynamic range is proposed. Contrary to the conventional fixed gap Pirani gauges, an electrostatic mechanism is employed to tune the gaseous conduction gap. Due to the electrostatic force between the heating element and heat sink, this tuning results in shifting the transition pressure to a higher pressure. As a result, the operating range of the Pirani gauge can be tuned depending on the magnitude of the actuation voltage. Theoretical estimation of the transition pressure corresponding to different gaseous conduction gaps is also presented. Depending on the available margin of gap tuning, the electromechanical and electrothermal analyses are carried out in COMSOL Multiphysics. The analytical approach is validated by experimentally characterizing the fabricated device. The experimentally tested device with the proposed actuation mechanism shows an 11.2 dB increase in dynamic range in comparison to the conventional design. In a CMOS-compatible fabrication process flow, the proposed gauge can be used to monitor vacuum from 40 Pa to 5×10^5 Pa with the electrostatic actuation.
本文提出了一种动态范围可调的静电致动全金属 MEMS 皮拉尼规。与传统的固定间隙皮拉尼真空计不同，它采用静电机制来调整气体传导间隙。由于加热元件和散热器之间存在静电力，这种调整会导致过渡压力向更高压力移动。因此，皮拉尼真空计的工作范围可根据致动电压的大小进行调整。此外，还对不同气体传导间隙对应的过渡压力进行了理论估算。根据可用的间隙调整余量，在 COMSOL Multiphysics 中进行了机电和电热分析。通过对制造的器件进行实验表征，验证了分析方法。与传统设计相比，采用拟议致动机制的实验测试器件的动态范围增加了 11.2 dB。在与 CMOS 兼容的制造工艺流程中，利用静电致动，所提出的真空计可用于监测从 40 Pa 到 5×10^5 Pa 的真空度。
{"title":"Electrostatically actuated all metal MEMS Pirani gauge with tunable dynamic range","authors":"Manu Garg, D. S. Arya, Sushil Kumar, Khanjan Joshi, M. Yousuf, Yi-Yen Chiu, PUSHPAPRAJ SINGH","doi":"10.1088/1361-6439/ad1b1a","DOIUrl":"https://doi.org/10.1088/1361-6439/ad1b1a","url":null,"abstract":"\u0000 An electrostatically actuated all-metal MEMS Pirani gauge with a tunable dynamic range is proposed. Contrary to the conventional fixed gap Pirani gauges, an electrostatic mechanism is employed to tune the gaseous conduction gap. Due to the electrostatic force between the heating element and heat sink, this tuning results in shifting the transition pressure to a higher pressure. As a result, the operating range of the Pirani gauge can be tuned depending on the magnitude of the actuation voltage. Theoretical estimation of the transition pressure corresponding to different gaseous conduction gaps is also presented. Depending on the available margin of gap tuning, the electromechanical and electrothermal analyses are carried out in COMSOL Multiphysics. The analytical approach is validated by experimentally characterizing the fabricated device. The experimentally tested device with the proposed actuation mechanism shows an 11.2 dB increase in dynamic range in comparison to the conventional design. In a CMOS-compatible fabrication process flow, the proposed gauge can be used to monitor vacuum from 40 Pa to 5×10^5 Pa with the electrostatic actuation.","PeriodicalId":16346,"journal":{"name":"Journal of Micromechanics and Microengineering","volume":"50 8","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139385803","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-01-04DOI: 10.1088/1361-6439/ad1b1c
José Andrés Santamaría Cordero, Hannia López Mena, Marisol Ledezma, Leslie W. Pineda, J. E. Duran Herrera
The rising concerns about CO2 levels in the atmosphere and energy dependency on non-renewable sources, such as fossil fuels, could find an integral solution in CO2 photocatalytic reduction. The present work explores two alternatives to the main hindering factors for this reaction, i.e., the reactor configuration and the photocatalyst utilized. A microreactor was designed and 3D printed, providing a cheap and versatile reaction platform. Three bismuth halide perovskites, Cs3Bi2Cl9, Cs3Bi2I9, and Cs4MnBi2Cl12, were synthesized and characterized by their band gaps (Eg); Cs3Bi2I9 presented the lowest Eg and was therefore chosen for further evaluation as potential CO2-reduction photocatalyst. Aqueous-phase photocatalytic CO2 reduction was achieved using this perovskite in the microreactor, obtaining CO as a reduction product with maximal production rates of 737 μmol gcat -1 h-1. The reaction system was evaluated under different flow rates and light intensities. A balance between space-time and reactant feed was found to define the behavior of CO concentration and production in the microreactor. For the light intensity, it was observed that as it increased, both CO production and concentration increased due to generating more electron-hole pairs, favoring the photocatalytic reaction. With these results, Cs3Bi2I9 perovskite immobilized in the designed microreactor demonstrates having great potential as an effective CO2 photocatalytic reduction system.
{"title":"Carbon dioxide reduction utilizing a bismuth halide perovskite as immobilized photocatalyst in a 3D printed microreactor","authors":"José Andrés Santamaría Cordero, Hannia López Mena, Marisol Ledezma, Leslie W. Pineda, J. E. Duran Herrera","doi":"10.1088/1361-6439/ad1b1c","DOIUrl":"https://doi.org/10.1088/1361-6439/ad1b1c","url":null,"abstract":"\u0000 The rising concerns about CO2 levels in the atmosphere and energy dependency on non-renewable sources, such as fossil fuels, could find an integral solution in CO2 photocatalytic reduction. The present work explores two alternatives to the main hindering factors for this reaction, i.e., the reactor configuration and the photocatalyst utilized. A microreactor was designed and 3D printed, providing a cheap and versatile reaction platform. Three bismuth halide perovskites, Cs3Bi2Cl9, Cs3Bi2I9, and Cs4MnBi2Cl12, were synthesized and characterized by their band gaps (Eg); Cs3Bi2I9 presented the lowest Eg and was therefore chosen for further evaluation as potential CO2-reduction photocatalyst. Aqueous-phase photocatalytic CO2 reduction was achieved using this perovskite in the microreactor, obtaining CO as a reduction product with maximal production rates of 737 μmol gcat\u0000 -1 h-1. The reaction system was evaluated under different flow rates and light intensities. A balance between space-time and reactant feed was found to define the behavior of CO concentration and production in the microreactor. For the light intensity, it was observed that as it increased, both CO production and concentration increased due to generating more electron-hole pairs, favoring the photocatalytic reaction. With these results, Cs3Bi2I9 perovskite immobilized in the designed microreactor demonstrates having great potential as an effective CO2 photocatalytic reduction system.","PeriodicalId":16346,"journal":{"name":"Journal of Micromechanics and Microengineering","volume":"38 4","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139385951","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-01-04DOI: 10.1088/1361-6439/ad1b1d
Stephen Binderup, V. Korampally
This paper presents a versatile nanotransfer printing method for achieving large-area sub-micron patterns of functional materials. Organosilicate ink formulations combined with effective release layers have been shown to facilitate patterning of materials through the commonly used patterning approaches – lift off, physical etching and chemical etching. In this paper, we demonstrate that organosilicate ink formulations function as an effective resist owing to its superior physico-chemical stability whereas the release layers ensure clean removal of the resist post patterning. We successfully demonstrate patterning of sub-micron structures (800 nm feature sizes) of chromium metal through the lift off approach, silicon through reactive ion etching technique and silicon dioxide through wet chemical etching technique illustrating the versatility of the reported method. This patterning methodology represents a significant advancement in enabling nanostructure fabrication within resource-constrained laboratories. The approach requires nothing more than a master mold containing the desired structures, a spin coater, a low-temperature hotplate, and a desktop reactive ion etch tool.
{"title":"Large Area Nanoscale Patterning of Functional Materials Using Organosilicate ink based Nanotransfer Printing","authors":"Stephen Binderup, V. Korampally","doi":"10.1088/1361-6439/ad1b1d","DOIUrl":"https://doi.org/10.1088/1361-6439/ad1b1d","url":null,"abstract":"\u0000 This paper presents a versatile nanotransfer printing method for achieving large-area sub-micron patterns of functional materials. Organosilicate ink formulations combined with effective release layers have been shown to facilitate patterning of materials through the commonly used patterning approaches – lift off, physical etching and chemical etching. In this paper, we demonstrate that organosilicate ink formulations function as an effective resist owing to its superior physico-chemical stability whereas the release layers ensure clean removal of the resist post patterning. We successfully demonstrate patterning of sub-micron structures (800 nm feature sizes) of chromium metal through the lift off approach, silicon through reactive ion etching technique and silicon dioxide through wet chemical etching technique illustrating the versatility of the reported method. This patterning methodology represents a significant advancement in enabling nanostructure fabrication within resource-constrained laboratories. The approach requires nothing more than a master mold containing the desired structures, a spin coater, a low-temperature hotplate, and a desktop reactive ion etch tool.","PeriodicalId":16346,"journal":{"name":"Journal of Micromechanics and Microengineering","volume":"33 4","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139385215","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The stiffness of the connecting beam is one of the most crucial factors affecting the performance of MEMS sensors. Many traditional methods reduce the stiffness by changing the parameters or number of connecting beams. This paper introduces a seven-shaped beam structure used for MEMS sensor. The acute angle between its two segments of seven-shaped structure realizes lower stiffness. Compared with the crab-leg beam, it can bring a maximum sensitivity gain of 1.29 times through different included angle designs. At the same time, compared with the combined beam, seven-shaped combined beam can bring a maximum sensitivity gain of 1.6 times. By using the seven-shaped beam, the two-dimensional MEMS sensor has been designed and fabricated. According to the experimental results, it achieved a detection sensitivity of 25 fF/g. The relative error of the differential capacitance change between the measurement result and the simulation result is only 8.6%.
{"title":"Seven-shaped beam design for improving the sensitivity of two-dimensional MEMS sensors","authors":"Nanyan Zhou, Wu Liu, Feng Cui, Xinwei Zhang, Leyang Lv","doi":"10.1088/1361-6439/ad1709","DOIUrl":"https://doi.org/10.1088/1361-6439/ad1709","url":null,"abstract":"\u0000 The stiffness of the connecting beam is one of the most crucial factors affecting the performance of MEMS sensors. Many traditional methods reduce the stiffness by changing the parameters or number of connecting beams. This paper introduces a seven-shaped beam structure used for MEMS sensor. The acute angle between its two segments of seven-shaped structure realizes lower stiffness. Compared with the crab-leg beam, it can bring a maximum sensitivity gain of 1.29 times through different included angle designs. At the same time, compared with the combined beam, seven-shaped combined beam can bring a maximum sensitivity gain of 1.6 times. By using the seven-shaped beam, the two-dimensional MEMS sensor has been designed and fabricated. According to the experimental results, it achieved a detection sensitivity of 25 fF/g. The relative error of the differential capacitance change between the measurement result and the simulation result is only 8.6%.","PeriodicalId":16346,"journal":{"name":"Journal of Micromechanics and Microengineering","volume":" 5","pages":""},"PeriodicalIF":2.3,"publicationDate":"2023-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138960716","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-11DOI: 10.1088/1361-6439/ad104b
Tony Thomas, Amit Agrawal
Microdevices have been recognized as a potential platform for performing numerous biomedical analysis and diagnostic applications. However, promising and viable techniques for a cost-effective and high throughput production of microfluidic devices still remain as a challenge. This paper addresses this problem with an alternative solution for the fabrication of microfluidic devices in a simple and efficient manner. We utilized laser-assisted engraving technique to fabricate a master mold on an acrylic sheet of different thicknesses from 4 to 20mm. Low cost indigenously developed CO2 (10.6μm wavelength) laser engraving device was used for the experiments. The effect of various laser parameters such as power and speed of operation on the height of engraved structures was studied in detail. Optimal engraving results were obtained with a laser speed of 200–250mm s−1 with a spacing interval of 0.002mm at a laser power of 10–12W. Master mold of microdevice with a channel width of 100μm were produced using this technique. The replica transfer was performed by a simple imprinting method using a benchtop universal testing machine that can provide a maximum compressive load upto 1kN. The replicas were successfully generated on various thin film substrates including polymers, plastics, Whatman filter paper, teflon, vinyl sheets, copper, and aluminum sheets. The effect of load applied on the depth of the microfluidic channel was studied for the substrates such as teflon and Whatman filter paper. A load of 1kN can generate a depth of a few hundred micrometers on various substrates mentioned above. The replicas were also transferred to thermoformable PETG (polyethylene terephthalate glycol) sheets under load with an elevated temperature. The channel-imprinted PETG substrates were later sandwiched between two acrylic sheets with adhesive-coated polymer sheets and screws at the corners. Soft lithographic techniques were also performed to replicate the channel on a poly dimethyl siloxane substrate which was later bonded to a glass plate using an oxygen plasma cleaner device. Fluidic flow testing was conducted by pumping dye-mixed deionized (DI) water through the channels using a syringe pump and connecting tubes at a constant flow rate of 5ml min−1. The outcomes of this study provide an alternative solution for a simple and low-cost method for microdevice fabrication at a large scale.
{"title":"Design and fabrication of microfluidic devices: a cost-effective approach for high throughput production","authors":"Tony Thomas, Amit Agrawal","doi":"10.1088/1361-6439/ad104b","DOIUrl":"https://doi.org/10.1088/1361-6439/ad104b","url":null,"abstract":"Microdevices have been recognized as a potential platform for performing numerous biomedical analysis and diagnostic applications. However, promising and viable techniques for a cost-effective and high throughput production of microfluidic devices still remain as a challenge. This paper addresses this problem with an alternative solution for the fabrication of microfluidic devices in a simple and efficient manner. We utilized laser-assisted engraving technique to fabricate a master mold on an acrylic sheet of different thicknesses from 4 to 20mm. Low cost indigenously developed CO<sub>2</sub> (10.6<italic toggle=\"yes\">μ</italic>m wavelength) laser engraving device was used for the experiments. The effect of various laser parameters such as power and speed of operation on the height of engraved structures was studied in detail. Optimal engraving results were obtained with a laser speed of 200–250mm s<sup>−1</sup> with a spacing interval of 0.002mm at a laser power of 10–12W. Master mold of microdevice with a channel width of 100<italic toggle=\"yes\">μ</italic>m were produced using this technique. The replica transfer was performed by a simple imprinting method using a benchtop universal testing machine that can provide a maximum compressive load upto 1kN. The replicas were successfully generated on various thin film substrates including polymers, plastics, Whatman filter paper, teflon, vinyl sheets, copper, and aluminum sheets. The effect of load applied on the depth of the microfluidic channel was studied for the substrates such as teflon and Whatman filter paper. A load of 1kN can generate a depth of a few hundred micrometers on various substrates mentioned above. The replicas were also transferred to thermoformable PETG (polyethylene terephthalate glycol) sheets under load with an elevated temperature. The channel-imprinted PETG substrates were later sandwiched between two acrylic sheets with adhesive-coated polymer sheets and screws at the corners. Soft lithographic techniques were also performed to replicate the channel on a poly dimethyl siloxane substrate which was later bonded to a glass plate using an oxygen plasma cleaner device. Fluidic flow testing was conducted by pumping dye-mixed deionized (DI) water through the channels using a syringe pump and connecting tubes at a constant flow rate of 5ml min<sup>−1</sup>. The outcomes of this study provide an alternative solution for a simple and low-cost method for microdevice fabrication at a large scale.","PeriodicalId":16346,"journal":{"name":"Journal of Micromechanics and Microengineering","volume":"34 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2023-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138686502","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-11DOI: 10.1088/1361-6439/ad0de8
Jun Yu, Ata Donmez, Hansaja Herath, Hanna Cho
This paper investigates the implementation of 1:2 internal resonance (InRes) in a clamped–clamped stepped beam resonator with a strong Duffing effect, focusing on its potential for frequency stabilization in micro-electro-mechanical systems (MEMS) resonators. InRes can arise in a nonlinear system of which mode frequencies are close to an integer ratio, facilitating the internal exchange of energy from an externally driven mode to an undriven mode. The presence of 1:2 InRes and Duffing hardening nonlinearity can result in frequency saturation phenomena, leading to a flat amplitude-frequency response range, which forms the basis for frequency stabilization. The stepped beam resonator design, combined with thermal frequency tuning, enables precise alteration of the frequency ratio between the second and third flexural modes required to achieve the desired 1:2 ratio for InRes. Experimental characterization and theoretical analysis revealed that frequency mismatch plays a significant role, with larger mismatch conditions leading to stronger energy exchange and a wider range of drive force for frequency saturation. The study highlights the frequency saturation mechanism utilizing 1:2 InRes and emphasizes the advantage of Duffing nonlinearity and larger intermodal frequency mismatch for broader frequency stabilization, providing valuable insights for the design and optimization of MEMS resonators.
{"title":"One-to-two internal resonance in a micro-mechanical resonator with strong Duffing nonlinearity","authors":"Jun Yu, Ata Donmez, Hansaja Herath, Hanna Cho","doi":"10.1088/1361-6439/ad0de8","DOIUrl":"https://doi.org/10.1088/1361-6439/ad0de8","url":null,"abstract":"This paper investigates the implementation of 1:2 internal resonance (InRes) in a clamped–clamped stepped beam resonator with a strong Duffing effect, focusing on its potential for frequency stabilization in micro-electro-mechanical systems (MEMS) resonators. InRes can arise in a nonlinear system of which mode frequencies are close to an integer ratio, facilitating the internal exchange of energy from an externally driven mode to an undriven mode. The presence of 1:2 InRes and Duffing hardening nonlinearity can result in frequency saturation phenomena, leading to a flat amplitude-frequency response range, which forms the basis for frequency stabilization. The stepped beam resonator design, combined with thermal frequency tuning, enables precise alteration of the frequency ratio between the second and third flexural modes required to achieve the desired 1:2 ratio for InRes. Experimental characterization and theoretical analysis revealed that frequency mismatch plays a significant role, with larger mismatch conditions leading to stronger energy exchange and a wider range of drive force for frequency saturation. The study highlights the frequency saturation mechanism utilizing 1:2 InRes and emphasizes the advantage of Duffing nonlinearity and larger intermodal frequency mismatch for broader frequency stabilization, providing valuable insights for the design and optimization of MEMS resonators.","PeriodicalId":16346,"journal":{"name":"Journal of Micromechanics and Microengineering","volume":"1 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2023-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138686541","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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