Pub Date : 2024-09-11DOI: 10.1088/1361-6439/ad76b5
Jingwei Yang, Lintong Han, Hongxin Wang, Hongnan Zhou, Limin Zhang and Lipeng He
In order to satisfy the market’s demand for high-consistency, micro-dispensing of colloids, an embedded lever-amplified piezoelectric dispensing valve based on flexure hinge is designed. This structure has stable jetting performance, strong reliability, and can achieve micro-dispensing of medium and low viscosity glue. Theoretical analysis shows that the output displacement of the piezoelectric stack can meet the displacement requirement of dispensing after being amplified by this amplification mechanism. And the output displacement and mode of the amplification mechanism are calculated and analyzed by simulation. The rationality of the simulation model is verified by experiments, and the effect law of driving voltage, signal duty cycle and working frequency on the mass of glue droplets is obtained. The results show that under the conditions of driving voltage 100 V, duty cycle 50%, glue supply pressure 0.6 MPa, working frequency 100 Hz, the consistency deviation of single dispensing amount is ±2.01%, as a whole, 0.34–0.38 mg of uniform tiny glue dots can be obtained. The experimental results have verified the stability and micro-dispensing performance of the embedded lever amplification piezoelectric dispensing valve, providing reference for the subsequent application and research of jet dispensing.
{"title":"Design and performance analysis of an embedded amplified piezoelectric jetting dispensing valve","authors":"Jingwei Yang, Lintong Han, Hongxin Wang, Hongnan Zhou, Limin Zhang and Lipeng He","doi":"10.1088/1361-6439/ad76b5","DOIUrl":"https://doi.org/10.1088/1361-6439/ad76b5","url":null,"abstract":"In order to satisfy the market’s demand for high-consistency, micro-dispensing of colloids, an embedded lever-amplified piezoelectric dispensing valve based on flexure hinge is designed. This structure has stable jetting performance, strong reliability, and can achieve micro-dispensing of medium and low viscosity glue. Theoretical analysis shows that the output displacement of the piezoelectric stack can meet the displacement requirement of dispensing after being amplified by this amplification mechanism. And the output displacement and mode of the amplification mechanism are calculated and analyzed by simulation. The rationality of the simulation model is verified by experiments, and the effect law of driving voltage, signal duty cycle and working frequency on the mass of glue droplets is obtained. The results show that under the conditions of driving voltage 100 V, duty cycle 50%, glue supply pressure 0.6 MPa, working frequency 100 Hz, the consistency deviation of single dispensing amount is ±2.01%, as a whole, 0.34–0.38 mg of uniform tiny glue dots can be obtained. The experimental results have verified the stability and micro-dispensing performance of the embedded lever amplification piezoelectric dispensing valve, providing reference for the subsequent application and research of jet dispensing.","PeriodicalId":16346,"journal":{"name":"Journal of Micromechanics and Microengineering","volume":"60 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142188714","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 : 2024-09-11DOI: 10.1088/1361-6439/ad750f
Sabitha Ann Jose, Yahya Atwa, Faisal Iqbal, David McNeill and Hamza Shakeel
Ultra-low expansion (ULE) glasses, with their excellent material properties like low thermal expansion coefficient (0.5 ppm K−1), are highly suitable for manufacturing micromechanical resonators. However, the lack of suitable microfabrication processes primarily limits the use of ULE glasses to macroscopic applications. This paper describes a detailed micro fabrication technique for producing double paddle oscillators (DPOs) using ULE glass substrates. We used a combination of low-pressure chemical vapor deposition (LPCVD), lithography, and wet etching techniques to manufacture millimeter sized mechanical oscillator with a thickness of 500 μm. We utilized a thick layer of LPCVD polysilicon (∼2.5 μm) as a hard mask for double side etching of thick ULE substrate. We were able to successfully identify different resonant modes of the DPOs using both electrostatic and optical detection methods. A laser Doppler vibrometer system was utilized to confirm different simulated resonant modes. Additionally, quality factor was extracted for different modes from ring down measurements for the first time in ULE based DPO.
{"title":"Fabrication of ultra-low expansion glass based double paddle oscillator","authors":"Sabitha Ann Jose, Yahya Atwa, Faisal Iqbal, David McNeill and Hamza Shakeel","doi":"10.1088/1361-6439/ad750f","DOIUrl":"https://doi.org/10.1088/1361-6439/ad750f","url":null,"abstract":"Ultra-low expansion (ULE) glasses, with their excellent material properties like low thermal expansion coefficient (0.5 ppm K−1), are highly suitable for manufacturing micromechanical resonators. However, the lack of suitable microfabrication processes primarily limits the use of ULE glasses to macroscopic applications. This paper describes a detailed micro fabrication technique for producing double paddle oscillators (DPOs) using ULE glass substrates. We used a combination of low-pressure chemical vapor deposition (LPCVD), lithography, and wet etching techniques to manufacture millimeter sized mechanical oscillator with a thickness of 500 μm. We utilized a thick layer of LPCVD polysilicon (∼2.5 μm) as a hard mask for double side etching of thick ULE substrate. We were able to successfully identify different resonant modes of the DPOs using both electrostatic and optical detection methods. A laser Doppler vibrometer system was utilized to confirm different simulated resonant modes. Additionally, quality factor was extracted for different modes from ring down measurements for the first time in ULE based DPO.","PeriodicalId":16346,"journal":{"name":"Journal of Micromechanics and Microengineering","volume":"3 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142224653","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 : 2024-09-11DOI: 10.1088/1361-6439/ad76b6
Junce Cheng and Tingyi ‘Leo’ Liu
This paper presents a novel idea to create cut-resistant superhydrophobic (SHPo) surfaces by integrating an array of SU-8 micropillars on a highly entangled polyacrylamide (PAAm) hydrogel substrate. We begin by demonstrating that this highly entangled PAAm hydrogel exhibits superior resistance to cutting while being as transparent, flexible, and stretchable as other polymeric substrates like polydimethylsiloxane (PDMS). Currently, there are no well-known methods or chemicals to directly integrate SU-8 and PAAm with a covalent bond. To overcome this challenge, we introduce a thin layer of chemically modified PDMS between the SU-8 and PAAm so that covalent bonds can be formed between both the SU-8/PDMS interface and the PDMS/PAAm interface. After validating the reliability of the bonding in our experiments, we develop a heterogeneous integration process to fabricate the desired SHPo surface. To demonstrate the critical role of PAAm hydrogel in achieving the cut-resistant SHPo surface, we contrast this new SHPo surface with a reference version that uses a PDMS substrate instead. We conduct microscopic inspections using scanning electron microscopy and a contact angle goniometer before and after cutting the two surfaces. These evaluations show significant differences in their structural integrity and behavior in water interaction.
{"title":"Heterogeneous micro-architectonic integration of SU-8 and highly entangled polyacrylamide hydrogel to realize cut-resistant soft superhydrophobic surfaces","authors":"Junce Cheng and Tingyi ‘Leo’ Liu","doi":"10.1088/1361-6439/ad76b6","DOIUrl":"https://doi.org/10.1088/1361-6439/ad76b6","url":null,"abstract":"This paper presents a novel idea to create cut-resistant superhydrophobic (SHPo) surfaces by integrating an array of SU-8 micropillars on a highly entangled polyacrylamide (PAAm) hydrogel substrate. We begin by demonstrating that this highly entangled PAAm hydrogel exhibits superior resistance to cutting while being as transparent, flexible, and stretchable as other polymeric substrates like polydimethylsiloxane (PDMS). Currently, there are no well-known methods or chemicals to directly integrate SU-8 and PAAm with a covalent bond. To overcome this challenge, we introduce a thin layer of chemically modified PDMS between the SU-8 and PAAm so that covalent bonds can be formed between both the SU-8/PDMS interface and the PDMS/PAAm interface. After validating the reliability of the bonding in our experiments, we develop a heterogeneous integration process to fabricate the desired SHPo surface. To demonstrate the critical role of PAAm hydrogel in achieving the cut-resistant SHPo surface, we contrast this new SHPo surface with a reference version that uses a PDMS substrate instead. We conduct microscopic inspections using scanning electron microscopy and a contact angle goniometer before and after cutting the two surfaces. These evaluations show significant differences in their structural integrity and behavior in water interaction.","PeriodicalId":16346,"journal":{"name":"Journal of Micromechanics and Microengineering","volume":"23 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142188718","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 : 2024-09-11DOI: 10.1088/1361-6439/ad72ff
Nguyen Nhu Hieu and Pham Ngoc Chung
In this study, a novel approach based on the elliptic balance method (EBM) is proposed for the first time to find the approximate frequency of nano/micro-electromechanical systems modeled as Euler–Bernoulli beams under the effects of electrostatic and van der Waals interaction forces. Firstly, the governing equation of the beam is reduced to the single-mode vibration equation using the Galerkin method. A nonlinear differential equation for the time-dependent beam deflection is obtained. We present the approximate solution as an elliptic cosine function, which considers the free term contributing to the solution. This free term is relevant for vibrations with a non-zero mean in time, in which the beam is affected by a relatively large applied voltage. Via some manipulations, the obtained result is an algebraic equation with only one unknown in three unknowns: the free and vibration coefficient terms, and the modulus quantity of the elliptic cosine function. This nonlinear equation is solved using the Newton–Raphson method. The numerical results from the EBM show that the accuracy of the solution responses in time and approximate frequency is relatively accurate, almost coinciding with the results obtained from the numerical solution method using the Runge–Kutta algorithm. Our results also agree well with previously published experimental and simulation results. The results are meaningful when determining the frequency of the vibrating beam with high accuracy for micro/nano systems.
{"title":"A highly accurate analytical method for determination of the vibrational frequency of N/MEMS with electrostatic and van der Waals interaction forces","authors":"Nguyen Nhu Hieu and Pham Ngoc Chung","doi":"10.1088/1361-6439/ad72ff","DOIUrl":"https://doi.org/10.1088/1361-6439/ad72ff","url":null,"abstract":"In this study, a novel approach based on the elliptic balance method (EBM) is proposed for the first time to find the approximate frequency of nano/micro-electromechanical systems modeled as Euler–Bernoulli beams under the effects of electrostatic and van der Waals interaction forces. Firstly, the governing equation of the beam is reduced to the single-mode vibration equation using the Galerkin method. A nonlinear differential equation for the time-dependent beam deflection is obtained. We present the approximate solution as an elliptic cosine function, which considers the free term contributing to the solution. This free term is relevant for vibrations with a non-zero mean in time, in which the beam is affected by a relatively large applied voltage. Via some manipulations, the obtained result is an algebraic equation with only one unknown in three unknowns: the free and vibration coefficient terms, and the modulus quantity of the elliptic cosine function. This nonlinear equation is solved using the Newton–Raphson method. The numerical results from the EBM show that the accuracy of the solution responses in time and approximate frequency is relatively accurate, almost coinciding with the results obtained from the numerical solution method using the Runge–Kutta algorithm. Our results also agree well with previously published experimental and simulation results. The results are meaningful when determining the frequency of the vibrating beam with high accuracy for micro/nano systems.","PeriodicalId":16346,"journal":{"name":"Journal of Micromechanics and Microengineering","volume":"8 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142188712","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 : 2024-09-06DOI: 10.1088/1361-6439/ad6e97
Anupam Choubey, Supreet Singh Bahga
Hot embossing is a scalable method of fabricating microfluidic devices involving precise replication of micrometer-sized features from a master mold onto a thermoplastic substrate. Typically, high-resolution master molds for hot embossing are fabricated using expensive, resource-intensive processes such as photolithography and electron-beam lithography. Here, we present a maskless, cost-effective, and rapid microfabrication process based on electrohydrodynamic jet printing (EJP) for fabricating high-resolution reusable master templates for hot embossing of thermoplastic microfluidic devices. Our method is based on EJP to fabricate intricate polymeric templates, with feature sizes of order 100 µm, followed by a double casting process to obtain stiff PDMS master molds. Using these PDMS molds, we demonstrate the hot embossing of microfluidic devices with excellent reproducibility across multiple embossing cycles. In particular, we demonstrate the fabrication of microfluidic devices with simple geometries of cross-shape and Y-shape to complex geometries of flow-focusing droplet generator and tree-shaped gradient generator. Subsequently, we demonstrate the use of hot-embossed microfluidic devices for hydrodynamic focusing, droplet generation, and stable concentration gradient generation. Our method offers a low-cost and rapid alternative to traditional lithographic processes for fabricating master molds for hot embossing with comparable feature resolution.
{"title":"Electrohydrodynamic jet printed templates for hot embossing of microfluidic devices","authors":"Anupam Choubey, Supreet Singh Bahga","doi":"10.1088/1361-6439/ad6e97","DOIUrl":"https://doi.org/10.1088/1361-6439/ad6e97","url":null,"abstract":"Hot embossing is a scalable method of fabricating microfluidic devices involving precise replication of micrometer-sized features from a master mold onto a thermoplastic substrate. Typically, high-resolution master molds for hot embossing are fabricated using expensive, resource-intensive processes such as photolithography and electron-beam lithography. Here, we present a maskless, cost-effective, and rapid microfabrication process based on electrohydrodynamic jet printing (EJP) for fabricating high-resolution reusable master templates for hot embossing of thermoplastic microfluidic devices. Our method is based on EJP to fabricate intricate polymeric templates, with feature sizes of order 100 <italic toggle=\"yes\">µ</italic>m, followed by a double casting process to obtain stiff PDMS master molds. Using these PDMS molds, we demonstrate the hot embossing of microfluidic devices with excellent reproducibility across multiple embossing cycles. In particular, we demonstrate the fabrication of microfluidic devices with simple geometries of cross-shape and Y-shape to complex geometries of flow-focusing droplet generator and tree-shaped gradient generator. Subsequently, we demonstrate the use of hot-embossed microfluidic devices for hydrodynamic focusing, droplet generation, and stable concentration gradient generation. Our method offers a low-cost and rapid alternative to traditional lithographic processes for fabricating master molds for hot embossing with comparable feature resolution.","PeriodicalId":16346,"journal":{"name":"Journal of Micromechanics and Microengineering","volume":"7 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142188716","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}
This study presents a compact 3.8 × 3.8 mm2 resonant piezoelectric micro-electro-mechanical systems scanner featuring a 1.0 mm mirror and double-coupling frames. It employs a novel mechanical coupling of two Pb(Zr,Ti)O3 piezoelectric actuators–fork-shaped and ring-shaped. This dual-actuator configuration enhances the efficiency of actuator area usage per die and significantly improves the resonant frequency through their mechanical coupling. Additionally, the design strategy effectively reduces mechanical stress by operating the scanning frequency above those of other modes. The resonant frequency achieved by the proposed scanner is 27.09 kHz, with an optical scan angle of 40∘, utilizing a unipolar driving voltage of 25.2 V.
本研究提出了一种紧凑型 3.8 × 3.8 mm2 谐振压电微机电系统扫描仪，具有 1.0 mm 镜面和双耦合框架。它采用了两种 Pb（Zr,Ti）O3 压电致动器（叉形和环形）的新型机械耦合。这种双致动器配置提高了每个芯片的致动器面积使用效率，并通过其机械耦合显著提高了谐振频率。此外，这种设计策略还能使扫描频率高于其他模式，从而有效降低机械应力。利用 25.2 V 的单极驱动电压，拟议扫描仪的谐振频率为 27.09 kHz，光学扫描角度为 40∘。
{"title":"3.8 × 3.8 mm2 compact piezoelectric resonant MEMS scanner using fork-shaped and ring-shaped actuators","authors":"Yuki Okamoto, Rihachiro Nakashima, Ryo Oda, Sucheta Gorwadkar, Yusuke Takei, Hironao Okada","doi":"10.1088/1361-6439/ad72fe","DOIUrl":"https://doi.org/10.1088/1361-6439/ad72fe","url":null,"abstract":"This study presents a compact 3.8 × 3.8 mm<sup>2</sup> resonant piezoelectric micro-electro-mechanical systems scanner featuring a 1.0 mm mirror and double-coupling frames. It employs a novel mechanical coupling of two Pb(Zr,Ti)O<sub>3</sub> piezoelectric actuators–fork-shaped and ring-shaped. This dual-actuator configuration enhances the efficiency of actuator area usage per die and significantly improves the resonant frequency through their mechanical coupling. Additionally, the design strategy effectively reduces mechanical stress by operating the scanning frequency above those of other modes. The resonant frequency achieved by the proposed scanner is 27.09 kHz, with an optical scan angle of 40<sup>∘</sup>, utilizing a unipolar driving voltage of 25.2 V.","PeriodicalId":16346,"journal":{"name":"Journal of Micromechanics and Microengineering","volume":"9 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142188719","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}
In recent years, there has been significant development in microfluidic devices for cell separation and sorting using acoustic methods in biomedical applications. The acoustic interparticle force (AIF) or the secondary acoustic radiation force arises from particle interactions with the scattered field of other particles, influencing particle motion at close ranges and facilitating optimal trapping and separation. This study analyzes a two-particle system consisting of a fixed particle and a white blood cell (WBC) within a standing acoustic field and creeping flow using fluid-structure interaction (FSI). To reduce computational costs by decoupling the acoustics and FSI, the acoustic pressure equation was solved on the frequency domain to calculate the total acoustic radiation force in each time step. Model accuracy was assessed by evaluating interparticle (AIF) and primary acoustic radiation force (ARF) on a polystyrene particle and comparing simulation results to analytical and experimental data. Results demonstrate the precise primary ARF computation, with discrepancies in AIF attributed to viscous losses near the particle surface. Moreover, the higher density of the fixed particle compared to WBCs induces significant acoustic interparticle attraction at close distances. Consequently, cell entrapment occurs through strong attraction and collision with fixed aluminum and silicon particles in creeping flow in all three Reynolds numbers 1.4 × 10−3, 2.1 × 10−3, and 3 × 10−3. Increasing Reynolds numbers augment the likelihood of cell separation from the fixed particle. These findings contribute to optimizing cell isolation and entrapment strategies.
{"title":"Three-dimensional FSI simulation of cell entrapment utilizing acoustic interparticle force in a standing acoustic field","authors":"Kamran Hafezi, Mohsen Saghafian, Davood Saeidi, Hamid Reza Aghaie","doi":"10.1088/1361-6439/ad6f1f","DOIUrl":"https://doi.org/10.1088/1361-6439/ad6f1f","url":null,"abstract":"In recent years, there has been significant development in microfluidic devices for cell separation and sorting using acoustic methods in biomedical applications. The acoustic interparticle force (AIF) or the secondary acoustic radiation force arises from particle interactions with the scattered field of other particles, influencing particle motion at close ranges and facilitating optimal trapping and separation. This study analyzes a two-particle system consisting of a fixed particle and a white blood cell (WBC) within a standing acoustic field and creeping flow using fluid-structure interaction (FSI). To reduce computational costs by decoupling the acoustics and FSI, the acoustic pressure equation was solved on the frequency domain to calculate the total acoustic radiation force in each time step. Model accuracy was assessed by evaluating interparticle (AIF) and primary acoustic radiation force (ARF) on a polystyrene particle and comparing simulation results to analytical and experimental data. Results demonstrate the precise primary ARF computation, with discrepancies in AIF attributed to viscous losses near the particle surface. Moreover, the higher density of the fixed particle compared to WBCs induces significant acoustic interparticle attraction at close distances. Consequently, cell entrapment occurs through strong attraction and collision with fixed aluminum and silicon particles in creeping flow in all three Reynolds numbers 1.4 × 10<sup>−3</sup>, 2.1 × 10<sup>−3</sup>, and 3 × 10<sup>−3</sup>. Increasing Reynolds numbers augment the likelihood of cell separation from the fixed particle. These findings contribute to optimizing cell isolation and entrapment strategies.","PeriodicalId":16346,"journal":{"name":"Journal of Micromechanics and Microengineering","volume":"35 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142188717","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 : 2024-09-03DOI: 10.1088/1361-6439/ad6f1c
Gang Wang, Changhua You, Liu Yang, Daoyin Liu, Huanhuan Zeng, Ning Xue, Lei Yao
This study presents the design and implementation of a heterogenous integrated neural recording system consisting of a flexible Au-PDMS-PEG probe and customized complementary metal oxide semiconductor (CMOS) application-specific integrated circuit (ASIC) in a standard 0.18 μm process. The flexible Au-PDMS-PEG probe was prepared by an elastocapillary self-assembled process, achieving an electrode impedance of 250 kΩ (@1 kHz). The customized CMOS ASIC contains 36 modular digital pixels (MDP). It achieves 5.69 μVrms input referred noise, 10.29 effective number of bits, 49.5 μW power consumption, and 0.092 mm2 area for a single MDP unit. Spontaneous spikes were also recorded in the mouse cortex, with a peak-to-peak amplitude of 389.2 μVPP and a signal-to-noise ratio of 19.36. Benchtop and in-vivo experiments were conducted to validate the functionality and performance of the proposed neural recording system.
{"title":"A heterogenous integrated neural recording system with elastocapillary self-assembled Au-PDMS-PEG neural probe and customized ASIC","authors":"Gang Wang, Changhua You, Liu Yang, Daoyin Liu, Huanhuan Zeng, Ning Xue, Lei Yao","doi":"10.1088/1361-6439/ad6f1c","DOIUrl":"https://doi.org/10.1088/1361-6439/ad6f1c","url":null,"abstract":"This study presents the design and implementation of a heterogenous integrated neural recording system consisting of a flexible Au-PDMS-PEG probe and customized complementary metal oxide semiconductor (CMOS) application-specific integrated circuit (ASIC) in a standard 0.18 <italic toggle=\"yes\">μ</italic>m process. The flexible Au-PDMS-PEG probe was prepared by an elastocapillary self-assembled process, achieving an electrode impedance of 250 kΩ (@1 kHz). The customized CMOS ASIC contains 36 modular digital pixels (MDP). It achieves 5.69 <italic toggle=\"yes\">μ</italic>V<sub>rms</sub> input referred noise, 10.29 effective number of bits, 49.5 <italic toggle=\"yes\">μ</italic>W power consumption, and 0.092 mm<sup>2</sup> area for a single MDP unit. Spontaneous spikes were also recorded in the mouse cortex, with a peak-to-peak amplitude of 389.2 <italic toggle=\"yes\">μ</italic>V<sub>PP</sub> and a signal-to-noise ratio of 19.36. Benchtop and <italic toggle=\"yes\">in-vivo</italic> experiments were conducted to validate the functionality and performance of the proposed neural recording system.","PeriodicalId":16346,"journal":{"name":"Journal of Micromechanics and Microengineering","volume":"7 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142188722","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}
This study presents the piezoelectric microspeaker design consisted of the central-diaphragm, connecting-spring, and cantilever-plate actuators to create two resonances in the desired frequency range. In addition to the cantilever-plate actuator, the electrical routing and piezoelectric film are designed to drive the central-diaphragm independently. According to the stress distributions on the microspeaker structure for both lower and higher modes, the all-pass filter circuit is designed and implemented to manage the phase of input signals to the central-diaphragm, thereby changing the motion of the proposed design. Thus, the sound pressure level (SPL) beyond 1 kHz is improved and the SPL zero at specific frequency range is avoided. As a result, the bandwidth enhancement is achieved by the proposed microspeaker. Measurements are conducted under 0.707 Vrms with 9 VDC driving voltage in standard ear simulator to evaluate the performances of the proposed design. A reference design without a piezoelectric film on the central-diaphragm is also implemented for comparison. Measurements indicate, in the low frequency range (before 4 kHz), the proposed designs have over 3 dB SPL enhancement due to the excitation of central-diaphragm. Moreover, compared to the reference design, proposed designs prevent the occurrence of an SPL zero near 10 kHz (between lower and higher modes) and achieve over 15 dB SPL enhancement. When the driving frequency exceeds the higher mode (14 kHz), the proposed design with the all-pass filter eliminates the SPL zero (at 16.8 kHz) with nearly 8 dB enhancement in the 15–18 kHz frequency range. Thus, this study demonstrates the bandwidth enhancement by the proposed microspeaker design with central-diaphragm actuation and all-pass filter integration.
{"title":"Bandwidth enhancement of piezoelectric MEMS microspeaker via central diaphragm actuation and filter integration","authors":"Chia-Hao Lin, Ting-Chou Wei, Chin Tseng, Zih-Song Hu, Mei-Feng Lai, Weileun Fang","doi":"10.1088/1361-6439/ad6f1e","DOIUrl":"https://doi.org/10.1088/1361-6439/ad6f1e","url":null,"abstract":"This study presents the piezoelectric microspeaker design consisted of the central-diaphragm, connecting-spring, and cantilever-plate actuators to create two resonances in the desired frequency range. In addition to the cantilever-plate actuator, the electrical routing and piezoelectric film are designed to drive the central-diaphragm independently. According to the stress distributions on the microspeaker structure for both lower and higher modes, the all-pass filter circuit is designed and implemented to manage the phase of input signals to the central-diaphragm, thereby changing the motion of the proposed design. Thus, the sound pressure level (SPL) beyond 1 kHz is improved and the SPL zero at specific frequency range is avoided. As a result, the bandwidth enhancement is achieved by the proposed microspeaker. Measurements are conducted under 0.707 V<sub>rms</sub> with 9 V<sub>DC</sub> driving voltage in standard ear simulator to evaluate the performances of the proposed design. A reference design without a piezoelectric film on the central-diaphragm is also implemented for comparison. Measurements indicate, in the low frequency range (before 4 kHz), the proposed designs have over 3 dB SPL enhancement due to the excitation of central-diaphragm. Moreover, compared to the reference design, proposed designs prevent the occurrence of an SPL zero near 10 kHz (between lower and higher modes) and achieve over 15 dB SPL enhancement. When the driving frequency exceeds the higher mode (14 kHz), the proposed design with the all-pass filter eliminates the SPL zero (at 16.8 kHz) with nearly 8 dB enhancement in the 15–18 kHz frequency range. Thus, this study demonstrates the bandwidth enhancement by the proposed microspeaker design with central-diaphragm actuation and all-pass filter integration.","PeriodicalId":16346,"journal":{"name":"Journal of Micromechanics and Microengineering","volume":"23 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142188720","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 : 2024-08-27DOI: 10.1088/1361-6439/ad6fab
Gakuto Kagawa, Hidetoshi Takahashi
This study utilized liquid-immersion inclined-rotated ultraviolet lithography to fabricate three-dimensional (3D) microstructures. The maximum achievable inclination angles obtained through conventional inclined-rotated exposure (IRE) methods were limited by the significant refractive index differences in material. We proposed an IRE with liquid-immersion and adjustable mirrors, which enabled greater inclination angles with improved adjustability. Using liquid as a medium helped minimize the refractive index disparities between materials. We fabricated polydimethylsiloxane molds for micro suction cup (MSC) array sheets to evaluate the performance of the developed liquid-immersion IRE. The resulting MSC array sheets (10 mm2) with a suction cup diameter of 500 μm, achieved inclination angles up to 51°, approximately double those obtained with the conventional IRE method. In addition, the suction force of the fabricated MSC arrays were evaluated by pulling along the vertical, horizontal, and edge directions under wet conditions. The maximum measured suction force was 0.15 N, confirming the effectiveness of the proposed liquid-immersion IRE in fabricating 3D microstructures, as demonstrated by the fabricated MSC array sheets.
{"title":"Liquid-immersion inclined-rotated exposure system for fabricating three-dimensional microstructures with large inclination angles","authors":"Gakuto Kagawa, Hidetoshi Takahashi","doi":"10.1088/1361-6439/ad6fab","DOIUrl":"https://doi.org/10.1088/1361-6439/ad6fab","url":null,"abstract":"This study utilized liquid-immersion inclined-rotated ultraviolet lithography to fabricate three-dimensional (3D) microstructures. The maximum achievable inclination angles obtained through conventional inclined-rotated exposure (IRE) methods were limited by the significant refractive index differences in material. We proposed an IRE with liquid-immersion and adjustable mirrors, which enabled greater inclination angles with improved adjustability. Using liquid as a medium helped minimize the refractive index disparities between materials. We fabricated polydimethylsiloxane molds for micro suction cup (MSC) array sheets to evaluate the performance of the developed liquid-immersion IRE. The resulting MSC array sheets (10 mm<sup>2</sup>) with a suction cup diameter of 500 <italic toggle=\"yes\">μ</italic>m, achieved inclination angles up to 51°, approximately double those obtained with the conventional IRE method. In addition, the suction force of the fabricated MSC arrays were evaluated by pulling along the vertical, horizontal, and edge directions under wet conditions. The maximum measured suction force was 0.15 N, confirming the effectiveness of the proposed liquid-immersion IRE in fabricating 3D microstructures, as demonstrated by the fabricated MSC array sheets.","PeriodicalId":16346,"journal":{"name":"Journal of Micromechanics and Microengineering","volume":"13 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142188721","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：