Journal of Micromechanics and Microengineering最新文献

{"title":"Effects of rolled fibrous microstructure on fatigue properties of extruded Cu-5Al planar micro springs","authors":"Feiyin Li, Xiubing Wang, Shaojie Ma, X. Dong, Xinping Zhang","doi":"10.1088/1361-6439/acf13a","DOIUrl":"https://doi.org/10.1088/1361-6439/acf13a","url":null,"abstract":"Planar micro spring is an important elastic component in microelectromechanical system devices, and one of its main failures is fatigue. In this work, a new method to improve the cycles of a planar micro spring by introducing pre-rolled fibrous microstructure was proposed. Cu-5Al alloy billets with a fibrous microstructure rolled at room temperature with a reduction ratio of 70% were obtained. Three types of planar micro springs with fibrous microstructure were prepared through extrusion by varying the angle between the fibrous microstructure direction and the extrusion direction. Fatigue tests were conducted using a customized micro-fatigue test system. The best fatigue performance was obtained by preparing the micro springs with the fibrous microstructure direction perpendicular to the extrusion direction, while the worst fatigue performance was obtained by preparing the planar micro springs with the fibrous microstructure direction parallel to the extrusion direction. The fibrous microstructure direction affected the local strain in the micro springs. The fibrous microstructure slightly affected the location of the crack initiation region but significantly affected the area of crack initiation and steady-state expansion region of the micro spring. The fatigue life cycle of extruded Cu-5Al alloy planar micro spring with the pre-rolled fibrous microstructure improved by 58% more than that of extruded Cu-7Al alloy planar micro spring without the pre-rolled fibrous microstructure. Micro spring fatigue life cycle decreased with increasing strain amplitude. This work provides a new approach for preparing planar micro springs with high fatigue performance.","PeriodicalId":16346,"journal":{"name":"Journal of Micromechanics and Microengineering","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2023-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44302568","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}

{"title":"Effect of SiO2 protective layer on LiNbO3 structured SAW resonators and temperature characteristics study","authors":"Liu Qiang, Wen-Lin Yang, Cheng Chi, Hongyuan Li, Xu Hong","doi":"10.1088/1361-6439/acef33","DOIUrl":"https://doi.org/10.1088/1361-6439/acef33","url":null,"abstract":"In this paper, using LiNbO3 as the piezoelectric substrate, Pt as the electrode and SiO2 as the protective layer, a multi-physics field coupled finite element model was used to investigate the effect of the protective layer thickness on the Rayleigh wave propagation characteristics, and the relationship between the protective layer thickness and the frequency–temperature coefficient TCF and electromechanical coupling coefficient K 2 is established. The frequency characteristics of the device and the microscopic changes of the electrode and substrate structures under high temperature were analyzed experimentally. The results show that no acoustic mode shift occurs when the normalized thickness is less than 31.25%. As the thickness of the protective layer increases, the vibration displacement in the direction of L wave, SH wave and SV wave decreases, and the thickness of the protective layer can be increased appropriately to reduce the interference of SH wave to Rayleigh wave; |TCF| decreases with increasing thickness of the protective layer. Changes in the thickness of the protective layer at different temperatures lead to fluctuations in K 2; the protective layer structure leads to a slight decrease in Q value. As the temperature increases, the fluctuation of the resonant frequency of the SAW resonator increases. The SiO2 protective layer can effectively protect LiNbO3 materials while improving the high-temperature working stability of Pt electrodes.","PeriodicalId":16346,"journal":{"name":"Journal of Micromechanics and Microengineering","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2023-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48034923","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}

{"title":"A novel micro-device for simultaneous separation-trapping and double-trapping of particles by using dielectrophoresis: numerical and experimental study","authors":"M. Aghdasi, M. Nazari, Sareh Yonesi","doi":"10.1088/1361-6439/acef32","DOIUrl":"https://doi.org/10.1088/1361-6439/acef32","url":null,"abstract":"Dielectrophoretic (DEP) force is a useful tool for manipulating particles in microfluidic systems. It is affected by the frequency of the applied electric field, which can be varied to produce repellent and attractive forces depending on the dielectric properties of particles and the media. In this work, two electric fields with different frequency are used to simultaneously separate and trap particles as well as double-trap particles by utilizing the DEP force. Initially, a single-vial microchannel was proposed to study the impact of the frequency and voltage on three types of electrodes: concentrator, repellent, and absorbing. The goal was to examine their efficacy in trapping a group of particles within the vial while separating and ejecting another group of particles from the microchannel. Performance graphs were used to determine the optimal voltages for the electrodes. Subsequently, an additional vial is incorporated into the microchannel to enable the double-trapping of particles with varying sizes and properties. With the optimal design, particles of varying sizes and properties can be trapped in separate vials within the microchannel. For the first time, the performance cartography of the proposed system has been assessed, enabling the identification of the optimal values and intelligent separations. Validation is conducted in two steps. Firstly, numerical findings are compared to previous experimental results to verify the accuracy of the numerical approach. Secondly, a microchip is fabricated, tested, and compared to numerical results using yeast cells to assess system efficiency and enhance the reliability of the numerical technique.","PeriodicalId":16346,"journal":{"name":"Journal of Micromechanics and Microengineering","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2023-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47624880","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}

{"title":"Three-dimensional AC electroosmotic micropump with high power density","authors":"M. Watanabe, Kazuhiro Yoshida, Joon-wan Kim, S. Eom, S. Yokota","doi":"10.1088/1361-6439/acef31","DOIUrl":"https://doi.org/10.1088/1361-6439/acef31","url":null,"abstract":"This paper presents a novel three-dimensional alternating current electroosmosis (ACEO) micropump with high power density. ACEO is a phenomenon to generate a flow of a liquid such as water by applying an AC voltage to the liquid. Using a specific configuration, a net flow due to ACEO becomes unidirectional and an ACEO micropump can be constructed. Many ACEO micropumps have been proposed; however, most of them are of the planar type, and their output power per device volume is not sufficiently high for applications such as micro fluid power sources for micro total analysis systems, lab-on-a-chips, biomedical microelectromechanical systems (bio-MEMSs), soft microactuators, and soft microrobots. To achieve a higher output power density, in this study, we proposed an ACEO micropump using an array of plate-cylinder electrodes, which is called PC-ACEO-MP. To induce unidirectional flow efficiently, a square pole-slit electrodes ACEO micropump called SS-ACEO-MP has been proposed using asymmetrical pillar-shaped electrodes. PC-ACEO-MP is an extension of SS-ACEO-MP with a three-dimensional structure. First, the finite element method simulations were performed and the results showed that PC-ACEO-MP has the potential to realize high output power with a 1 cm3 effective pump volume using large numbers of plate-cylinder electrodes connected in parallel and in series. Second, a fabrication method using MEMS fabrication process, including electroplating, was proposed and developed for a micro-holed electrode plate that forms parallel cylinder electrodes. The validity of the proposed process was confirmed by fabricating large models and micro-models of the micro-holed electrode plate. The diameter and number of microholes were 10 μm and 36 100, respectively, for the large models and 3 μm and 65 500, respectively, for the micro models. Finally, PC-ACEO-MPs were constructed and their promising pumping characteristics were clarified through experiments using deionized water. The estimated power density was approximately 400 times higher than that of the former high output power ACEO micropump.","PeriodicalId":16346,"journal":{"name":"Journal of Micromechanics and Microengineering","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2023-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45616033","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}

{"title":"Experimental study on acoustic-induced microbubbles fusion","authors":"Shaobo Jin, N. Cao, G. Ye, P. Wang, Shizhang Dong, Zenghao Liu","doi":"10.1088/1361-6439/acee87","DOIUrl":"https://doi.org/10.1088/1361-6439/acee87","url":null,"abstract":"Droplets/microbubbles fusion technology is a key technology for many biochemical medical applications. Here, an acoustic-controlled approach to drive microbubble fusion based on focused surface acoustic wave (FSAW) is presented. When passing through the arc-shaped channel, adjacent microbubbles will decelerate, contact, and fuse induced by the FSAWs. Due to the cooperation of the FSAW and the arc-shaped flow channel structure, the microbubbles are more easily captured and fused with the adjacent microbubbles. The effects of input voltage and pressure input parameters on the microbubble fusion are studied. Relying on electrical input parameters, microbubble fusion can be effectively achieved, providing a new idea for precise gas fuse control. The regulation of the microbubbles fusion by FSAW is revealed, showing potential in the applications of the precise control of gases on a microfluidic chip.","PeriodicalId":16346,"journal":{"name":"Journal of Micromechanics and Microengineering","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2023-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49545656","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}

{"title":"Mass transfer characteristics at cathode/electrolyte interface during electrodeposition of nickel microcolumns with various aspect ratios","authors":"Yanzhuo Dong, Bingyan Jiang, D. Drummer, Lu Zhang","doi":"10.1088/1361-6439/acee8a","DOIUrl":"https://doi.org/10.1088/1361-6439/acee8a","url":null,"abstract":"The filling behavior of electrodeposited microcolumns is strongly influenced by the mass transfer characteristics at the cathode/electrolyte interface. This study aims to elucidate the influence of the mass transfer characteristics (ion supplementation via diffusion and ion consumption via deposition) on the electrodeposition of microcolumns, thus providing feasible solutions for improving void defects with different feature sizes. The results indicate that ion consumption plays an important role in the mass transfer within large-width microcavities (100 μm). For large-width microcolumns, longer electroforming times lead to higher ion consumption, resulting in nonuniform ion concentration distribution, and consequently uneven deposition rates along the microcavity wall. In microcavities with high aspect ratio (5:1), ion supplementation plays a major role. The low ion supplementation rate does not support a uniform deposition, resulting in a large void defect and a low filling ratio in the deposited microcolumns. Therefore, reducing the ion consumption rate by decreasing the current density from 1 A dm−2 to 0.25 A dm−2 can effectively increase the filling ratio in large-width microcolumns with no significant effect on high aspect ratio microcolumns. On the contrary, the pulse reverse current (forward pulse current density 1 A dm−2, reverse pulse current density 2 A dm−2, frequency 1 Hz, forward pulse duty cycle 0.9) can increase the filling ratio in the high aspect ratio microcolumns by accelerating ion supplementation through dissolution of the deposited layer. By further increasing the reverse pulse current density from 2 A dm−2 to 6 A dm−2, void defects can be completely eliminated and even void-free deposition of high aspect ratio microcolumns (5:1) can be achieved.","PeriodicalId":16346,"journal":{"name":"Journal of Micromechanics and Microengineering","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2023-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42366436","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}

{"title":"An improved dissipative particle dynamics method for the liquid-particle two-phase flow in microchannels","authors":"Hua Dong, Xu Wu, Liang-Liang Fan, Liang Zhao","doi":"10.1088/1361-6439/acee88","DOIUrl":"https://doi.org/10.1088/1361-6439/acee88","url":null,"abstract":"Liquid-particle two-phase flow in microchannel widely exists in the fields of biomedical and environmental monitoring, such as the lab-chip device for disease diagnosis. The standard dissipative particle dynamics (DPD) method has been previously employed to study the liquid-particle two-phase flow in microchannel, but it cannot accurately simulate the real process because of the unsuitable DPD parameters. In the present study, an improved DPD method was developed by changing the system energy and fitting the characteristic curve between the random force coefficient and the Schmidt number. In addition, a new logarithmic relationship between the conservative force coefficient and the particle size was found. The result demonstrated that the improved DPD method enabled more accurate simulation on the liquid-particle two-phase flow in microchannels than the standard DPD method. For instance, in the simulation of particle sedimentation, the relative deviation between the value obtained by the improved DPD method and the theoretical value was less than 6% while the relative deviation was more than 20% for the standard DPD method. The simulated result of the particle migration in microchannel was in good agreement with the result obtained by Matas et al, and the relative deviation was less than 1.5%. Therefore, the improved DPD method would have great potentials in the study on the liquid-particle two-phase flow in microchannels.","PeriodicalId":16346,"journal":{"name":"Journal of Micromechanics and Microengineering","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2023-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47924880","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}

{"title":"Bottom-up micromachined PZT film-based ultrasonic microphone with compressible parylene tube","authors":"Chung-Hao Huang, G. Feng","doi":"10.1088/1361-6439/acee89","DOIUrl":"https://doi.org/10.1088/1361-6439/acee89","url":null,"abstract":"This paper reports on a micromachined ultrasonic microphone using a bottom-up fabrication scheme. Starting with a 4 μm-thick titanium foil as the substrate, each functional film and key element was added to the foil substrate to complete the ultrasonic microphone. The piezoelectric lead zirconate titanate film hydrothermally grown on the patterned substrate with low residual stress effectively deflected the unimorph-sensing cantilever array of the microphone under ultrasound pressure. The created cantilever array structure secured on a 250 μm-thick SU8 hollow plate formed an ultrasonic microphone plate that was tested with a sensitivity of −60 dBV Pa−1 at 21 kHz (with 0 dB gain amplification) and an operation bandwidth of 5–55 kHz. Different thicknesses of parylene films ranging from 0.5 to 2 μm overlaid over the entire sensing region and converted the cantilever-to-diaphragm-structured microphone for further investigation. An enhanced result was observed when the deposited parylene film thickness was in the submicron range. The sensitivity of the microphone can be further enhanced by up to 33% by adding a parylene-film-made compressible tube to act as a Helmholtz resonator (HR). The HR model was discussed and compared with the experimental results. The output amplitude of the developed microphone assembled with the compressible tube demonstrates a 15 dB increase compared to that of a commercial capacitive MEMS ultrasonic microphone.","PeriodicalId":16346,"journal":{"name":"Journal of Micromechanics and Microengineering","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2023-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49003953","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}

{"title":"Flexible pressure/temperature sensors with heterogeneous integration of ultra-thin silicon and polymer","authors":"Weiwen Feng, Peng Li, Haozhi Zhang, Ke Sun, Wei Li, Xinxin Li","doi":"10.1088/1361-6439/acee8b","DOIUrl":"https://doi.org/10.1088/1361-6439/acee8b","url":null,"abstract":"Flexible pressure sensors and temperature sensors are widely used in various fields because of their advantages in high flexibility, good shape retention and extremely small thickness. However, it is quite challenging to fabricate ultra-thin flexible pressure sensors with reliable sensing performance. In this work, we propose a new type of silicon–polymer heterogeneously integrated MEMS flexible sensor with an ultra-thin silicon-based absolute pressure sensing element and a thermistor. In the study, a flexible MEMS fabrication process is developed, which enables simultaneous fabrication in two different substrates and self-release of the thin and slim flexible sensor. The front-end section of the flexible sensor is with the width as 125 μm, length as 3.2 cm and total thickness as 12 μm, where the integrated silicon substrate thickness is only 3 μm. The sensor takes a slender shape to allow for medical invasive measurement by inserting it into a slim medical catheter or a syringe needle-tube. The sensitivity of the fabricated ultra-thin absolute pressure sensor is tested as 45.2 μV kPa−1 under 3.3 V supplied voltage, with the nonlinearity as only ±0.16% FS. The sensitivity of the thermistor is 10.4 Ω °C−1 in the range of 0 °C–100 °C. Moreover, the polysilicon thermistor can also serve as a micro-heater, where an electric heating power of 107 μW results in a temperature increase of 13.5 °C. With ultra-thin slim structure and satisfactory performance, the MEMS flexible sensor is promising in various fields like biomedical applications.","PeriodicalId":16346,"journal":{"name":"Journal of Micromechanics and Microengineering","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2023-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46272677","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}

{"title":"Design and research of a valve-based piezoelectric pump with low forward resistance and high reverse shutoff","authors":"Yong Zhang, Jinyu Li, Xiaoliang Wang, Junqing Shao, Shanlin Liu, Qiaosheng Pan","doi":"10.1088/1361-6439/acec7f","DOIUrl":"https://doi.org/10.1088/1361-6439/acec7f","url":null,"abstract":"This paper proposes, designs, manufactures and experimentally studies a wedge valve piezoelectric pump driven by a double displacement amplifier vibrator (DDAV). A novel wedge valve is designed, manufactured and analyzed, and the static performance of the wedge valve is tested. The test results show that it has less forward resistance and high reverse shutoff. The DDAV and pump body are designed, and the test experimental platform is built. Results indicate that the static opening pressure of the wedge valve is 0.27 kPa, and the reverse shutoff pressure can reach 200 kPa. When the driving voltage is 700 Vpp and the driving frequency is 425 Hz, the maximum flow rate is 491.2 ml min−1 and the maximum output pressure is 160 kPa.","PeriodicalId":16346,"journal":{"name":"Journal of Micromechanics and Microengineering","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2023-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45756446","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}