Journal of Micromechanics and Microengineering最新文献

{"title":"Experimental investigation of electrostatic spinning of polylactic acid porous nanofibers","authors":"Tao Wang, Xue Shang, Hu Wang, Jilai Wang, Chengpeng Zhang","doi":"10.1088/1361-6439/ad6e98","DOIUrl":"https://doi.org/10.1088/1361-6439/ad6e98","url":null,"abstract":"Porous nanofibers are widely used in the fields of water treatment, sensors, energy storage and biomedicine. In this paper, environmentally friendly polylactic acid material was used to achieve controlled fabrication of porous nanofibers using electrostatic spinning technology. Taking fiber diameter and fiber aperture as evaluation indexes, the effects of process parameters on the formation of porous nanofiber were investigated respectively through single-factor experiments, including solution concentration, solvent ratio and feed rate. The results showed that the solution concentration and feed rate were the most important parameters affecting fiber diameter, and the solvent ratio was the most important parameter affecting fiber aperture. The coupling effect of these three parameters was analyzed using response surface experiments and controlled fabrication of porous nanofibers was achieved with diameters ranging from 1.470 to 3.298 <italic toggle=\"yes\">μ</italic>m and apertures ranging from 0.062 to 0.22 <italic toggle=\"yes\">μ</italic>m.","PeriodicalId":16346,"journal":{"name":"Journal of Micromechanics and Microengineering","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2024-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142224654","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":"Nucleic acid purification through nanoarchitectonics: magnetic bead integration with microfluidic chip technology","authors":"P Ramya Priya, K S Deepak, Satish Kumar Dubey, Sanket Goel","doi":"10.1088/1361-6439/ad6f1d","DOIUrl":"https://doi.org/10.1088/1361-6439/ad6f1d","url":null,"abstract":"Purified DNA and Polymerase Chain Reaction (PCR) are crucial parts of molecular biology techniques in various fields such as genomics, forensics, and diagnostics. The proposed microfluidic device is used to perform several steps like the adsorption of DNA present in processed PCR onto bare magnetic beads, cleaning of contaminants with ethanol-diluted buffer reagent, and eluting the adsorbed DNA in an elution buffer, which is further used for downstream application. The entire sample purification is accomplished in about 25 min. A comparative analysis is conducted using a commercially available DNA purification kit. By employing the suggested microfluidic chip alongside the commercial kit, a commercial spectrophotometer is utilized to measure the purity. This is done by obtaining the A260/A280 ratio, which allows for the assessment of both the quantity and purity of the extracted DNA. The A260/A280 ratios for the spin column-based, magnetic stand-based, and microfluidic chip- based tests were 1.86, 1.98, and 1.74, respectively. The analysis of the eluted DNA findings indicated that the quality was suitable for future PCR amplification. Additionally, this microchip-based device has the potential to be utilized as a bedside device for DNA purification in point of care applications, with a purification time of 25 min.","PeriodicalId":16346,"journal":{"name":"Journal of Micromechanics and Microengineering","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142188747","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":"From microchips to microneedles: semiconductor shear testers as a universal solution for transverse load analysis of microneedle mechanical performance","authors":"Kazim Haider, Thomas Lijnse, Wenting Shu, Eoin O’Cearbhaill, Colin Dalton","doi":"10.1088/1361-6439/ad6dfe","DOIUrl":"https://doi.org/10.1088/1361-6439/ad6dfe","url":null,"abstract":"Microneedles are a promising technology for pain-free and efficient pharmaceutical delivery. However, their clinical translation is currently limited by the absence of standardized testing methods for critical quality attributes (CQAs), such as mechanical robustness, which are essential for demonstrating safety and efficacy during regulatory review. A key aspect of mechanical robustness is transverse load capacity, which is currently assessed using diverse, non-standardized methods, which have limited capability to measure transverse failure forces at different heights along a microneedle. This is critical for understanding mechanics of potential failure modes during insertion after skin penetration. In this work we utilize a wire bond shear tester, a piece of test equipment widely used in the semiconductor industry, to measure the transverse load capacities of various microneedle designs. This approach is compatible with diverse microneedle types, geometries, and materials, and offers high-throughput and automated testing capabilities with high precision. We measure transverse failure loads with micron-scale control over the test height and have established comprehensive profiles of mechanical robustness along the length of different microneedle designs, which is a capability not previously demonstrated in literature for polymeric and metal microneedles. Transverse failure forces were 10 ± 0.3 gf–128 ± 12 gf for wire bonded gold and silver microneedles, 11 ± 0.7 gf–480 ± 69 gf for conical and pyramidal polymeric microneedles, and 206 ± 80 gf–381 ± 1 gf for 3D printed conical stainless steel microneedles. Additionally, we present standardized definitions for microneedle structural failure modes resulting from transverse loads, which can facilitate root cause failure analysis and defect detection during design and manufacturing, and aid in risk assessment of microneedle products. This work establishes a standardized approach to evaluating a significant CQA of microneedle products, which is a critical step towards expediting their clinical adoption.","PeriodicalId":16346,"journal":{"name":"Journal of Micromechanics and Microengineering","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142188723","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":"Lithographically patternable SU-8/Graphene nanocomposite based strain sensors for soft-MEMS applications","authors":"Faizan Tariq Beigh, Nadeem Tariq Beigh and Dhiman Mallick","doi":"10.1088/1361-6439/ad690e","DOIUrl":"https://doi.org/10.1088/1361-6439/ad690e","url":null,"abstract":"This paper presents an optimized, lithographically patternable SU-8/Graphene nanocomposite based piezoresistive strain sensor for localized, high-precision assessment, which marks a significant advancement in the field of soft-MEMS based technologies. The fabrication process involves the photolithography of a SU-8/Graphene nanocomposite with a minimum resolution of 50 μm, resulting in a material with excellent electrical conductivity and mechanical properties. Specifically, a 3% SU-8/Graphene composition was chosen to exceed the percolation threshold, enabling substantial changes in the resistance and facilitating photopatternability. The sensor exhibited exceptional performance characteristics, including a rapid response time of 0.1 s and a wide bending range from 0° to 60°. Notably, it demonstrated a remarkable %ΔR/R of 19.21, indicating its superior sensing capability. Such high sensitivity is crucial for applications that require precise, localized measurements, such as biomedical engineering, sports science, and smart healthcare.","PeriodicalId":16346,"journal":{"name":"Journal of Micromechanics and Microengineering","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2024-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141948234","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":"Efficient strategy for frequency design and bandwidth extension of curved piezoelectric ultrasonic micromachined transducers","authors":"Hao Li, Xiaofan Hu, Xingli Xu, Yongquan Ma, Chenyang Yu, Wei Wei and Pengfei Niu","doi":"10.1088/1361-6439/ad690d","DOIUrl":"https://doi.org/10.1088/1361-6439/ad690d","url":null,"abstract":"This article proposes an efficient analytical model and strategy for designing curved piezoelectric micromachined ultrasonic transducers (curved PMUTs). The model is developed based on the Donnell–Mushtari–Vlasov theory and the equivalent single layer method, and validated through finite element analysis. Utilizing the model, we further analyze the diaphragm’s vibration modes and key design parameters. The proposed strategy is centered on 2 design equations, facilitating the rapid design of devices at any frequency through parametric sweeps. Furthermore, to minimize bandwidth loss, we employ the merging of adjacent vibration modes to broaden the bandwidth. Using the proposed method for modes merging, we have effortlessly designed devices with operating frequencies of 2.15 MHz, 6.3 MHz, 10.65 MHz, and 18.75 MHz in water. For comparison, we also designed planar PMUTs and general curved PMUTs operating around 6 MHz and 15 MHz. Compared to planar PMUTs, curved PMUTs show exceptional performance improvements in output pressure and sensitivity. Moreover, the proposed strategy for bandwidth extension results in 1.33× and 1.25× bandwidth improvements around 6 MHz and 15 MHz. The proposed design methodology is anticipated to assist engineers in designing high-performance PMUT arrays more efficiently and systematically.","PeriodicalId":16346,"journal":{"name":"Journal of Micromechanics and Microengineering","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2024-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141948233","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":"Recent advances in piezoelectric and triboelectric self-powered sensors for human-machine interface applications","authors":"Lei Du, Yulong Li, Ruizhe Qiu, Jiaxing Xu, Kai Nie, Xinyu Cao, Jiaqi Tang, Yiqing Wang, Gang Du, Ling Bu","doi":"10.1088/1361-6439/ad6778","DOIUrl":"https://doi.org/10.1088/1361-6439/ad6778","url":null,"abstract":"\u0000 The burgeoning internet of things (IoTs) and artificial intelligence (AI) technologies have prospered a variety of emerging applications. Human-machine interfaces (HMIs), for instance, enables users with intuitive, efficient, and friendly way to interact with machines, capable of instant information acquisition, processing, communication, and feedback, etc. These features require ultra-compact and high-performance transducers, and therefore self-powered sensors have become the key underlying technology for HMI applications. This review focuses on the piezoelectric, triboelectric, and hybrid self-powered sensors with particular attention to their microstructures and fabrication methods, showing that both traditional microfabrication and emerging fabrication methods like three-dimensional (3D) printing, electrospinning, and braiding have contributed to the planar, array, porous, fabric, and composite type self-powered sensors. Moreover, the integration method of piezoelectric and triboelectric sensor arrays (TSAs) is investigated. The crosstalk issue is highlighted, i.e. the signal interference between adjacent sensing units, and current solutions such as array design optimization, signal processing improvement, and material innovation to reduce crosstalk sensitivity have been reviewed through specific examples. Three categories of HMI applications have been outlined, including intelligent interaction, robotics, and human monitoring, with detailed explanations of how the self-powered sensors support these HMI applications. Through discussion of challenges and prospects, it is proposed that further coordinating the design and fabrication of micro devices with HMIs will potentially boost the intelligent application with even higher level of diversification, convenience, and interconnectivity.","PeriodicalId":16346,"journal":{"name":"Journal of Micromechanics and Microengineering","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2024-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141805813","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":"Numerical Simulation of the Nebulizer with Multiple Orifices","authors":"Zexuan Chen, Daniela Butan, Seamus Clifford, Russell Greaney, Sean Cunningham, Philip Griffin","doi":"10.1088/1361-6439/ad6779","DOIUrl":"https://doi.org/10.1088/1361-6439/ad6779","url":null,"abstract":"\u0000 A vibrating mesh nebulizer is a medical device that can break liquid medication into an aerosol of tiny droplets so that patients can inhale them to treat diseases. The volumetric flow rate of this kind of nebulizer is determined by many factors, including the orifice geometry, the vibration amplitude and the vibration mode shape. Thus, many experiments were designed to assess the effects of these different variables on flow rate and to find the optimal set of device parameters that maximises the flow rate. However, it can be very expensive to perform such physical experimentation with physical prototypes, which needs different orifice geometries to be fabricated for different test regimes. The orifice sizes are microscopic with diameters typically between 3 μm to 5 μm, thus, they are difficult to be fabricated with the exact shape and diameter that are required. Therefore, virtual prototyping by means of numerical simulation models are required as the orifice geometries and other factors can be easily changed in the simulation models. This study aims to provide a numerical simulation model that is experimentally validated. By comparing the simulated flow rates with the experimentally obtained flow rates, and the simulated droplet diameters with the experimentally obtained droplet diameters, it was found that the errors are all less than 10% which demonstrates this numerical simulation model is adequately validated by experiment. Thus, instead of carrying out expensive experiments, this simulation model can be used for predicting the volumetric flow rates for different prescribed orifice geometries. Furthermore, this paper also simulates the effects of viscosity and surface tension on the flow rate, where either viscosity or surface tension increases, the flow rate will decrease.","PeriodicalId":16346,"journal":{"name":"Journal of Micromechanics and Microengineering","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2024-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141804944","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":"The UmboMic: a PVDF cantilever microphone *","authors":"Aaron J Yeiser, Emma F Wawrzynek, John Z Zhang, Lukas Graf, Christopher I McHugh, Ioannis Kymissis, Elizabeth S Olson, Jeffrey H Lang and Hideko Heidi Nakajima","doi":"10.1088/1361-6439/ad5c6d","DOIUrl":"https://doi.org/10.1088/1361-6439/ad5c6d","url":null,"abstract":"Objective. We present the ‘UmboMic,’ a prototype piezoelectric cantilever microphone designed for future use with totally-implantable cochlear implants. Methods. The UmboMic sensor is made from polyvinylidene difluoride (PVDF) because of its low Young’s modulus and biocompatibility. The sensor is designed to fit in the middle ear and measure the motion of the underside of the eardrum at the umbo. To maximize its performance, we developed a low noise charge amplifier in tandem with the UmboMic sensor. This paper presents the performance of the UmboMic sensor and amplifier in fresh cadaveric human temporal bones. Results. When tested in human temporal bones, the UmboMic apparatus achieves an equivalent input noise of 32.3 dB SPL over the frequency range 100 Hz–7 kHz, good linearity, and a flat frequency response to within 10 dB from about 100 Hz–6 kHz. Conclusion. These results demonstrate the feasibility of a PVDF-based microphone when paired with a low-noise amplifier. The reported UmboMic apparatus is comparable in performance to a conventional hearing aid microphone. Significance. The proof-of-concept UmboMic apparatus is a promising step towards creating a totally-implantable cochlear implant. A completely internal system would enhance the quality of life of cochlear implant users.","PeriodicalId":16346,"journal":{"name":"Journal of Micromechanics and Microengineering","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2024-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141741813","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":"Two-layered microwell-array device for preparation of single-neuron culture samples","authors":"Ayaka Nakama and Takashi Yasuda","doi":"10.1088/1361-6439/ad5b00","DOIUrl":"https://doi.org/10.1088/1361-6439/ad5b00","url":null,"abstract":"When a single neuron is cultured in isolation from other neurons, its axon connects with its own dendrites to form a simple, independent network with no synaptic inputs from other neurons. This culture system enables detailed analysis of synaptic function and morphology change in neurites at the single-neuron level, which is useful for elucidating the pathogenesis of neurological diseases and for evaluating the efficacy of therapeutic drugs for them. However, there was previously no device technology capable of simultaneously forming multiple single-neuron samples while allowing co-culture with astrocytes, which is essential for culture of a single neuron isolated from other neurons. In this study, we propose a novel microwell-array device for preparing single-neuron samples. The device consists of an upper layer for cell seeding and a lower layer for cell culture. Each layer has 16 × 16 microwells, and the bottom of each well is made of a 1 μm thick silicon nitride membrane. The membrane of the upper well has one microhole for seeding a single neuron, and the lower membrane has multiple microholes for interaction between a single neuron and astrocytes which are co-cultured back-to-back on both sides of the membrane. When neurons are seeded into the upper well, only one of them passes through the microhole in the upper membrane and falls onto the lower membrane. We evaluated a seeding efficiency of single neurons by changing seeding hole diameter and seeding density. The results showed that the yield of more than 20% was obtained regardless of the seeding density when the seeding hole diameter was 13 μm. We also confirmed that single neurons seeded in this manner and co-cultured with astrocytes developed neurites and formed synapses. These results demonstrated the usefulness of this device for the preparation of single-neuron culture samples.","PeriodicalId":16346,"journal":{"name":"Journal of Micromechanics and Microengineering","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2024-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141741815","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":"Equivalent Electrical Circuits for Electroacoustic MEMS Design: A Review","authors":"R. Liechti","doi":"10.1088/1361-6439/ad63b4","DOIUrl":"https://doi.org/10.1088/1361-6439/ad63b4","url":null,"abstract":"\u0000 At the era of powerful computers, it’s tempting to employ finite element models early in the design phase of a device. However, especially for MEMS devices, the dimensional ratios and short wavelengths compared to the device’s dimensions, along with the involvement of multiple physics, can necessitate complex and computationally intensive models, making them impractical for optimization processes. Hence, reduced order models, like the lumped element model, are often preferred as they accurately represent complex system behavior within a defined frequency range. This review explores the use of lumped element models and their corresponding electrical equivalent circuits for simulating MEMS electro-acoustic devices, offering insights into their diverse applications within this specific domain.","PeriodicalId":16346,"journal":{"name":"Journal of Micromechanics and Microengineering","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2024-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141640892","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}