The bonding of glass substrates is an important process in the fabrication of glass micro/nanofluidic devices. In this study, the influence of the surface roughness of glass substrates after low-temperature bonding is investigated. It is found that plasma etching can be used to control the surface roughness to the range 2–9 nm. Substrates with a roughness of 5 nm or less can be bonded. The pressure capacity of devices tends to decrease with increasing surface roughness. A pressure capacity of 500 kPa or higher is obtained with a surface roughness of 2 nm or less. This criterion for bonding conditions can be applied to roughness formed by other methods (e.g. via a Cr layer). The proposed approach will facilitate the design and fabrication of glass micro/nanofluidic devices, especially those that complicated fabrication processes or embedding of multiple materials.
{"title":"Relationship between bonding strength and surface roughness in low-temperature bonding of glass for micro/nanofluidic device","authors":"Ryoichi Ohta, Kyojiro Morikawa, Yoshiyuki Tsuyama, Takehiko Kitamori","doi":"10.1088/1361-6439/ad104c","DOIUrl":"https://doi.org/10.1088/1361-6439/ad104c","url":null,"abstract":"The bonding of glass substrates is an important process in the fabrication of glass micro/nanofluidic devices. In this study, the influence of the surface roughness of glass substrates after low-temperature bonding is investigated. It is found that plasma etching can be used to control the surface roughness to the range 2–9 nm. Substrates with a roughness of 5 nm or less can be bonded. The pressure capacity of devices tends to decrease with increasing surface roughness. A pressure capacity of 500 kPa or higher is obtained with a surface roughness of 2 nm or less. This criterion for bonding conditions can be applied to roughness formed by other methods (e.g. via a Cr layer). The proposed approach will facilitate the design and fabrication of glass micro/nanofluidic devices, especially those that complicated fabrication processes or embedding of multiple materials.","PeriodicalId":16346,"journal":{"name":"Journal of Micromechanics and Microengineering","volume":"16 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2023-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138686787","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 : 2023-12-06DOI: 10.1088/1361-6439/ad104d
Chuang Yuan, Jianyu Fu, Fan Qu, Qiong Zhou
MEMS thermal vacuum sensors have been widely applied in many academic and industry fields, and pressure range is a key performance of MEMS thermal vacuum sensors. To extend the pressure range, a combined MEMS thermal vacuum sensor that consists of two diode-type MEMS thermal vacuum sensors in series is proposed in this work. The two diode-type sensors are designed to have different areas of sensitive region and distances between sensitive region and heat sink, and their responses to the pressure are from 3.0 × 10−3 to 3 × 104 Pa and from 1.7 × 10−2 to 4.4 × 105 Pa, respectively. By series-connecting them, the combined sensor achieves a pressure range of 1.3 × 10−3 to 6.9 × 105 Pa without any additional control circuit. In addition, it possesses a relatively small size of 400 × 300 μm2. These indicate that the combined MEMS thermal vacuum sensor has the characteristics of wide pressure range, high sensitivity and small size.
{"title":"A combined MEMS thermal vacuum sensor with a wide pressure range","authors":"Chuang Yuan, Jianyu Fu, Fan Qu, Qiong Zhou","doi":"10.1088/1361-6439/ad104d","DOIUrl":"https://doi.org/10.1088/1361-6439/ad104d","url":null,"abstract":"MEMS thermal vacuum sensors have been widely applied in many academic and industry fields, and pressure range is a key performance of MEMS thermal vacuum sensors. To extend the pressure range, a combined MEMS thermal vacuum sensor that consists of two diode-type MEMS thermal vacuum sensors in series is proposed in this work. The two diode-type sensors are designed to have different areas of sensitive region and distances between sensitive region and heat sink, and their responses to the pressure are from 3.0 × 10<sup>−3</sup> to 3 × 10<sup>4</sup> Pa and from 1.7 × 10<sup>−2</sup> to 4.4 × 10<sup>5</sup> Pa, respectively. By series-connecting them, the combined sensor achieves a pressure range of 1.3 × 10<sup>−3</sup> to 6.9 × 10<sup>5</sup> Pa without any additional control circuit. In addition, it possesses a relatively small size of 400 × 300 <italic toggle=\"yes\">μ</italic>m<sup>2</sup>. These indicate that the combined MEMS thermal vacuum sensor has the characteristics of wide pressure range, high sensitivity and small size.","PeriodicalId":16346,"journal":{"name":"Journal of Micromechanics and Microengineering","volume":"1 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2023-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138686331","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 : 2023-12-05DOI: 10.1088/1361-6439/ad124e
Ali Reda, Thomas Dargent, Steve Arscott
The dynamic response of a structure is a manifestation of its inherent characteristics, including material density, mechanical modulus, thermo- and viscoelastic properties, and geometric properties. Together, these factors influence how the material behaves in dynamic scenarios, dictating its damping properties and behaviour under varying forces. In this study we present a novel approach to accurately determine the flexural (bending) modulus of microscopic diameter natural fibres (flax) using microcantilever vibration analysis. Traditionally, the characterisation of the mechanical properties of fibres has relied on macroscopic methods such as tensile testing, which often results in high scatter in measurement data; furthermore, tensile testing does not accurately represent microscale or dynamic conditions and can be complex in terms of sample preparation and loading. To address this, we have developed a microscale technique involving the fabrication of microcantilevers using flat polypropylene support chips, inspired by microelectromechanical systems (MEMS) approaches. Our approach provides a refined method for accurately characterising the mechanical modulus of flax fibres, with reduced data dispersion compared to traditional macroscopic testing. Furthermore, by reducing the influence of inherent fibre defects and maintaining homogeneity along the length of the fibre, our micro-scale technique provides reliable modulus determination. This work opens up avenues for improved understanding and application of natural and man-made fibres, such as glass and optical fibres, in a variety of fields.
{"title":"Dynamic micromechanical measurement of the flexural modulus of micrometre-sized diameter single natural fibres using a vibrating microcantilever technique","authors":"Ali Reda, Thomas Dargent, Steve Arscott","doi":"10.1088/1361-6439/ad124e","DOIUrl":"https://doi.org/10.1088/1361-6439/ad124e","url":null,"abstract":"\u0000 The dynamic response of a structure is a manifestation of its inherent characteristics, including material density, mechanical modulus, thermo- and viscoelastic properties, and geometric properties. Together, these factors influence how the material behaves in dynamic scenarios, dictating its damping properties and behaviour under varying forces. In this study we present a novel approach to accurately determine the flexural (bending) modulus of microscopic diameter natural fibres (flax) using microcantilever vibration analysis. Traditionally, the characterisation of the mechanical properties of fibres has relied on macroscopic methods such as tensile testing, which often results in high scatter in measurement data; furthermore, tensile testing does not accurately represent microscale or dynamic conditions and can be complex in terms of sample preparation and loading. To address this, we have developed a microscale technique involving the fabrication of microcantilevers using flat polypropylene support chips, inspired by microelectromechanical systems (MEMS) approaches. Our approach provides a refined method for accurately characterising the mechanical modulus of flax fibres, with reduced data dispersion compared to traditional macroscopic testing. Furthermore, by reducing the influence of inherent fibre defects and maintaining homogeneity along the length of the fibre, our micro-scale technique provides reliable modulus determination. This work opens up avenues for improved understanding and application of natural and man-made fibres, such as glass and optical fibres, in a variety of fields.","PeriodicalId":16346,"journal":{"name":"Journal of Micromechanics and Microengineering","volume":"53 6","pages":""},"PeriodicalIF":2.3,"publicationDate":"2023-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138598539","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 : 2023-11-28DOI: 10.1088/1361-6439/ad0d80
Ioannis Lampouras, Mathias Holz, Steffen Strehle, Julia Körner
Dynamic-mode cantilever sensors are based on the principle of a one-side clamped beam being excited to oscillate at or close to its resonance frequency. An external interaction on the cantilever alters its oscillatory state, and this change can be detected and used for quantification of the external influence (e.g. a force or mass load). A very promising approach to significantly improve sensitivity without modifying the established laser-based oscillation transduction is the co-resonant coupling of a micro- and a nanocantilever. Thereby, each resonator is optimized for a specific purpose, i.e. the microcantilever for reliable oscillation detection and the nanocantilever for highest sensitivity through low rigidity and mass. To achieve the co-resonant state, the eigenfrequencies of micro- and nanocantilever need to be adjusted so that they differ by less than approximately 20%. This can either be realized by mass deposition or trimming of the nanocantilever, or by choice of dimensions. While the former is a manual and error-prone process, the latter would enable reproducible batch fabrication of coupled systems with predefined eigenfrequency matching states and therefore sensor properties. However, the approach is very challenging as it requires a precisely controlled fabrication process. Here, for the first time, such a process for batch fabrication of inherently geometrically eigenfrequency matched co-resonant cantilever structures is presented and characterized. It is based on conventional microfabrication techniques and the structures are made from 1 µm thick low-stress silicon nitride. They comprise the microcantilever and high aspect ratio nanocantilever (width 2 µm, thickness about 100 nm, lengths up to 80 µm) which are successfully realized with only minimal bending. An average yield of >80% of intact complete sensor structures per wafer is achieved. Desired geometric dimensions can be realized within ±1% variation for length and width of the microcantilever and nanocantilever length, ±10% and ±20% for the nanocantilever width and thickness, respectively, resulting in an average variation of its eigenfrequency by 11%. Furthermore, the dynamic oscillation properties are verified by vibration experiments in a scanning electron microscope. The developed process allows for the first time the batch fabrication of co-resonantly coupled systems with predefined properties and controlled matching states. This is an important step and crucial foundation for a broader applicability of the co-resonant approach for sensitivity enhancement of dynamic-mode cantilever sensors.
{"title":"Precisely controlled batch-fabrication of highly sensitive co-resonant cantilever sensors from silicon-nitride","authors":"Ioannis Lampouras, Mathias Holz, Steffen Strehle, Julia Körner","doi":"10.1088/1361-6439/ad0d80","DOIUrl":"https://doi.org/10.1088/1361-6439/ad0d80","url":null,"abstract":"Dynamic-mode cantilever sensors are based on the principle of a one-side clamped beam being excited to oscillate at or close to its resonance frequency. An external interaction on the cantilever alters its oscillatory state, and this change can be detected and used for quantification of the external influence (e.g. a force or mass load). A very promising approach to significantly improve sensitivity without modifying the established laser-based oscillation transduction is the co-resonant coupling of a micro- and a nanocantilever. Thereby, each resonator is optimized for a specific purpose, i.e. the microcantilever for reliable oscillation detection and the nanocantilever for highest sensitivity through low rigidity and mass. To achieve the co-resonant state, the eigenfrequencies of micro- and nanocantilever need to be adjusted so that they differ by less than approximately 20%. This can either be realized by mass deposition or trimming of the nanocantilever, or by choice of dimensions. While the former is a manual and error-prone process, the latter would enable reproducible batch fabrication of coupled systems with predefined eigenfrequency matching states and therefore sensor properties. However, the approach is very challenging as it requires a precisely controlled fabrication process. Here, for the first time, such a process for batch fabrication of inherently geometrically eigenfrequency matched co-resonant cantilever structures is presented and characterized. It is based on conventional microfabrication techniques and the structures are made from 1 <italic toggle=\"yes\">µ</italic>m thick low-stress silicon nitride. They comprise the microcantilever and high aspect ratio nanocantilever (width 2 <italic toggle=\"yes\">µ</italic>m, thickness about 100 nm, lengths up to 80 <italic toggle=\"yes\">µ</italic>m) which are successfully realized with only minimal bending. An average yield of <inline-formula>\u0000<tex-math><?CDATA ${gt} 80$?></tex-math>\u0000<mml:math overflow=\"scroll\"><mml:mrow><mml:mo>></mml:mo></mml:mrow><mml:mn>80</mml:mn></mml:math>\u0000<inline-graphic xlink:href=\"jmmad0d80ieqn1.gif\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula>% of intact complete sensor structures per wafer is achieved. Desired geometric dimensions can be realized within ±1% variation for length and width of the microcantilever and nanocantilever length, ±10% and ±20% for the nanocantilever width and thickness, respectively, resulting in an average variation of its eigenfrequency by 11%. Furthermore, the dynamic oscillation properties are verified by vibration experiments in a scanning electron microscope. The developed process allows for the first time the batch fabrication of co-resonantly coupled systems with predefined properties and controlled matching states. This is an important step and crucial foundation for a broader applicability of the co-resonant approach for sensitivity enhancement of dynamic-mode cantilever sensors.","PeriodicalId":16346,"journal":{"name":"Journal of Micromechanics and Microengineering","volume":"14 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2023-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138686245","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 : 2023-11-28DOI: 10.1088/1361-6439/ad0d7f
Behjat Kheiri Yeghaneh Azar, Mitra Nourbakhsh, M R Nasiraee, Kazem Mousavizadeh, Zahra Majd, Mohammad Ajoudanian, Sara Saeedi, Amirhossein Vahabi, Michael R Hamblin, Mahdi Karimi
One of the most common cancers and a main cause of death worldwide among women is breast cancer (BC). Combination therapy is being widely investigated to reduce the dose of chemotherapy drugs, prevent the development of drug resistance, and improve treatment outcomes. Here we tested PEI-PBA-SAP-F15 (PPSF) polymeric nanoparticles to efficiently deliver a microRNA antagonist (anti-miR19a-3p) to BC cell lines. We evaluated the combination of anti-miR19a-3p plus doxorubicin (DOX) in both 2D and 3D cell cultures. We cultured 3D tumor spheroids in an innovative microfluidic device that was fabricated using a 3D printing system. The PPSF polyplexes had the correct size and zeta potential to efficiently transfer anti-miR19a-3p into MCF7 cells. The expression level of phosphatase and tensin homolog (PTEN), the attainment gene of microRNA-19a-3p was increased. PTEN up-regulation inhibited cell migration and caused cell cycle arrest. Apoptosis was also significantly induced with the combination treatment. Confocal microscopy studies revealed that the population of dead cells was in an important degree higher in MCF7 spheroids transfected with anti-miR19a-3p-PPSF plus DOX.
{"title":"Combination of anti-miR19a-3p polyplex plus doxorubicin for breast cancer in 2D culture and apoptosis assay in 3D spheroids in a microwell device","authors":"Behjat Kheiri Yeghaneh Azar, Mitra Nourbakhsh, M R Nasiraee, Kazem Mousavizadeh, Zahra Majd, Mohammad Ajoudanian, Sara Saeedi, Amirhossein Vahabi, Michael R Hamblin, Mahdi Karimi","doi":"10.1088/1361-6439/ad0d7f","DOIUrl":"https://doi.org/10.1088/1361-6439/ad0d7f","url":null,"abstract":"One of the most common cancers and a main cause of death worldwide among women is breast cancer (BC). Combination therapy is being widely investigated to reduce the dose of chemotherapy drugs, prevent the development of drug resistance, and improve treatment outcomes. Here we tested PEI-PBA-SAP-F<sub>15</sub> (PPSF) polymeric nanoparticles to efficiently deliver a microRNA antagonist (anti-miR19a-3p) to BC cell lines. We evaluated the combination of anti-miR19a-3p plus doxorubicin (DOX) in both 2D and 3D cell cultures. We cultured 3D tumor spheroids in an innovative microfluidic device that was fabricated using a 3D printing system. The PPSF polyplexes had the correct size and zeta potential to efficiently transfer anti-miR19a-3p into MCF7 cells. The expression level of phosphatase and tensin homolog (PTEN), the attainment gene of microRNA-19a-3p was increased. PTEN up-regulation inhibited cell migration and caused cell cycle arrest. Apoptosis was also significantly induced with the combination treatment. Confocal microscopy studies revealed that the population of dead cells was in an important degree higher in MCF7 spheroids transfected with anti-miR19a-3p-PPSF plus DOX.","PeriodicalId":16346,"journal":{"name":"Journal of Micromechanics and Microengineering","volume":"144 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2023-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138686246","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 : 2023-11-28DOI: 10.1088/1361-6439/ad0d7e
Keewoong Haan, Kukjin Chun, Byung-Gook Park, Hyeon Cheol Kim, Bonghwan Kim
A vision sensor for simultaneous imaging and distance sensing is proposed herein. This vision sensor uses two images with a depth of field by two different aperture sizes to extract distance data. The aperture was fabricated through the microelectromechanical systems process. The optical parameter related to making a blur was precisely selected to reduce the active voltage and response time. The aperture measurement result showed that the maximum displacement of 1170 µm was obtained when 12 V was applied which enlarge aperture size from 2.75 mm to 3.92 mm. The response time was 16.6 ms with a rising and falling time of 6.2 and 10.4 ms, respectively. The distance data was obtained using the depth from defocus method, which compares the blurriness of two images using the aperture size. Through deep learning, the image and distance information were simultaneously obtained in a single camera. The result of a three-dimensional depth map showed an average accuracy of 98.7% when sensing the maximum distance of 10 m. To examine the accuracy of the device, experiments were conducted for different colors, and the result showed that maximum and minimum error rates of 3.46% and 1.83% were achieved, respectively. In addition, the error rate according to brightness was investigated, and the average error rate was maintained at 2.64% between 10 000 and 200 lx. The proposed sensor can be installed in self-driving robots, drones, and various smart devices.
{"title":"A vision sensor for simultaneous imaging and distance sensing in real-time","authors":"Keewoong Haan, Kukjin Chun, Byung-Gook Park, Hyeon Cheol Kim, Bonghwan Kim","doi":"10.1088/1361-6439/ad0d7e","DOIUrl":"https://doi.org/10.1088/1361-6439/ad0d7e","url":null,"abstract":"A vision sensor for simultaneous imaging and distance sensing is proposed herein. This vision sensor uses two images with a depth of field by two different aperture sizes to extract distance data. The aperture was fabricated through the microelectromechanical systems process. The optical parameter related to making a blur was precisely selected to reduce the active voltage and response time. The aperture measurement result showed that the maximum displacement of 1170 <italic toggle=\"yes\">µ</italic>m was obtained when 12 V was applied which enlarge aperture size from 2.75 mm to 3.92 mm. The response time was 16.6 ms with a rising and falling time of 6.2 and 10.4 ms, respectively. The distance data was obtained using the depth from defocus method, which compares the blurriness of two images using the aperture size. Through deep learning, the image and distance information were simultaneously obtained in a single camera. The result of a three-dimensional depth map showed an average accuracy of 98.7% when sensing the maximum distance of 10 m. To examine the accuracy of the device, experiments were conducted for different colors, and the result showed that maximum and minimum error rates of 3.46% and 1.83% were achieved, respectively. In addition, the error rate according to brightness was investigated, and the average error rate was maintained at 2.64% between 10 000 and 200 lx. The proposed sensor can be installed in self-driving robots, drones, and various smart devices.","PeriodicalId":16346,"journal":{"name":"Journal of Micromechanics and Microengineering","volume":"11 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2023-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138686401","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 : 2023-11-28DOI: 10.1088/1361-6439/ad0d81
Aleksandra Pokrzywnicka, Danylo Lizanets, Rafał Walczak
Transillumination microscopes, often with a simple lens-free optical configuration, combined with lab-on-a-chip devices are useful tools for the characterisation of various biological samples. A key issue with these devices is light transparency across a lab-on-a-chip structure. In this work we achieved this by embedding a glass window in a silicon membrane. Despite light transmission, the membrane could be pressure actuated. A second key issue is software analysis of the images due to the holographic nature of the captured images. In this paper, the technology of the silicon/glass membrane and results of porcine oocyte imaging during deformation are presented and compared with our previous micro-electro-mechanical system cytometer working with a reflective microscope. Thus, a unique device that deforms cells and allows deformation measurements with transillumination was developed.
{"title":"Transillumination lab-on-a-chip cytometer with silicon/glass membrane for image-based porcine oocyte deformation characterisation","authors":"Aleksandra Pokrzywnicka, Danylo Lizanets, Rafał Walczak","doi":"10.1088/1361-6439/ad0d81","DOIUrl":"https://doi.org/10.1088/1361-6439/ad0d81","url":null,"abstract":"Transillumination microscopes, often with a simple lens-free optical configuration, combined with lab-on-a-chip devices are useful tools for the characterisation of various biological samples. A key issue with these devices is light transparency across a lab-on-a-chip structure. In this work we achieved this by embedding a glass window in a silicon membrane. Despite light transmission, the membrane could be pressure actuated. A second key issue is software analysis of the images due to the holographic nature of the captured images. In this paper, the technology of the silicon/glass membrane and results of porcine oocyte imaging during deformation are presented and compared with our previous micro-electro-mechanical system cytometer working with a reflective microscope. Thus, a unique device that deforms cells and allows deformation measurements with transillumination was developed.","PeriodicalId":16346,"journal":{"name":"Journal of Micromechanics and Microengineering","volume":"22 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2023-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138686405","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 : 2023-11-28DOI: 10.1088/1361-6439/ad0e42
Noor Syamila, Amir Syahir Amir Hamzah, Thomas Laurell, Yusran Sulaiman, Shinya Ikeno, Wen Siang Tan, Asilah Ahmad Tajudin
The displacement of an electroactive monitoring agent, i.e., polyamidoamine dendrimers encapsulated gold nanoparticles (PAMAM-Au) upon the presence of a target antibody via acoustic streaming has been studied. Acoustic streaming has been used to improve the mass transfer and reduce the sample incubation rate, thus this study investigated its ability in enhancing the PAMAM-Au displacement efficiency of our immunosensor. For this purpose, the bio-nanogate components of maltose-binding protein carrying the antigenic determinant (MBP-aD) of hepatitis B surface antigen (HBsAg) as a bioreceptor was functionalized, followed by the monitoring agent i.e. PAMAM-Au on the electrode prior to the incubation with targeted anti-hepatitis B surface antigen (anti-HBsAg) antibody. The modified electrode was then coupled with a piezotransducer and connected to the signal transducer to induce acoustic streaming upon sample incubation. Under optimal acoustic actuation, the sample incubation time has been reduced from 20 min to 8 min via the enhancement of PAMAM-Au displacement induced by acoustic streaming. The result also demonstrated that the specificity and selectivity of the sensing platform under acoustic actuation are comparable to the static incubation in detecting the targeted antibody.
{"title":"Displacement of PAMAM-Au via acoustic streaming on an electrochemical immunosensing platform","authors":"Noor Syamila, Amir Syahir Amir Hamzah, Thomas Laurell, Yusran Sulaiman, Shinya Ikeno, Wen Siang Tan, Asilah Ahmad Tajudin","doi":"10.1088/1361-6439/ad0e42","DOIUrl":"https://doi.org/10.1088/1361-6439/ad0e42","url":null,"abstract":"The displacement of an electroactive monitoring agent, i.e., polyamidoamine dendrimers encapsulated gold nanoparticles (PAMAM-Au) upon the presence of a target antibody via acoustic streaming has been studied. Acoustic streaming has been used to improve the mass transfer and reduce the sample incubation rate, thus this study investigated its ability in enhancing the PAMAM-Au displacement efficiency of our immunosensor. For this purpose, the bio-nanogate components of maltose-binding protein carrying the antigenic determinant (MBP-aD) of hepatitis B surface antigen (HBsAg) as a bioreceptor was functionalized, followed by the monitoring agent i.e. PAMAM-Au on the electrode prior to the incubation with targeted anti-hepatitis B surface antigen (anti-HBsAg) antibody. The modified electrode was then coupled with a piezotransducer and connected to the signal transducer to induce acoustic streaming upon sample incubation. Under optimal acoustic actuation, the sample incubation time has been reduced from 20 min to 8 min via the enhancement of PAMAM-Au displacement induced by acoustic streaming. The result also demonstrated that the specificity and selectivity of the sensing platform under acoustic actuation are comparable to the static incubation in detecting the targeted antibody.","PeriodicalId":16346,"journal":{"name":"Journal of Micromechanics and Microengineering","volume":"40 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2023-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138686408","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 : 2023-11-09DOI: 10.1088/1361-6439/ad0848
Xin Wang, Yan Peng
Abstract Electrochemical micromachining refers an unconventional technology in the field of machining. With this technology, the ultrashort pulse power supplies are extensively used to address the issue of excessive machining of non-processing areas. However, the reduction of pulse duration is the only effective strategy to enhance the processing accuracy in ultra-short pulse electrochemical microfabrication. Nonetheless, the high cost of equipment and unsuitability in practical production has limited its progress. To resolve this issue, this paper proposes the use of a composite signal in electrochemical micromachining instead of ultrashort pulses. By changing the signal waveform during machining, the energy required for processing can be reduced with the same electromotive force input, thereby reducing the current used to decompose the anode in the circuit and effectively improving machining accuracy. This approach was employed to manufacture micro-structures on a pure nickel sheet, achieving micron-scale accuracy. Moreover, the same level of superior machining accuracy can be achieved when machining micro-structures on hard-to-cut super alloy plates.
{"title":"Micromachining of nickel and nickel-based alloy surfaces using composite signal","authors":"Xin Wang, Yan Peng","doi":"10.1088/1361-6439/ad0848","DOIUrl":"https://doi.org/10.1088/1361-6439/ad0848","url":null,"abstract":"Abstract Electrochemical micromachining refers an unconventional technology in the field of machining. With this technology, the ultrashort pulse power supplies are extensively used to address the issue of excessive machining of non-processing areas. However, the reduction of pulse duration is the only effective strategy to enhance the processing accuracy in ultra-short pulse electrochemical microfabrication. Nonetheless, the high cost of equipment and unsuitability in practical production has limited its progress. To resolve this issue, this paper proposes the use of a composite signal in electrochemical micromachining instead of ultrashort pulses. By changing the signal waveform during machining, the energy required for processing can be reduced with the same electromotive force input, thereby reducing the current used to decompose the anode in the circuit and effectively improving machining accuracy. This approach was employed to manufacture micro-structures on a pure nickel sheet, achieving micron-scale accuracy. Moreover, the same level of superior machining accuracy can be achieved when machining micro-structures on hard-to-cut super alloy plates.","PeriodicalId":16346,"journal":{"name":"Journal of Micromechanics and Microengineering","volume":" 39","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135191420","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 : 2023-11-08DOI: 10.1088/1361-6439/ad0aeb
Rina Lee, Hongbin Kim, Hoon Kim, Jinho Lee, Kyong Jin Cho, Jeongyun Kim
Abstract In this study, we developed a microfluidic in vitro wound healing model to overcome the existing limitations of traditional experimental methods in quantifying cell migration. We manufactured a microfluidic system equipped with a gradient concentration generator to control the reagent density and with microvalves so the wound masking pattern could be automatically controlled by a programable Arduino board. A wound healing experiment of human corneal epithelial cells using eight different concentrations of ursolic acid with eight replicates was conducted simultaneously using our microfluidic system. A microfluidic in vitro wound healing model using human corneal epithelial cells involving a programable Arduino board for automatic process control was established to provide a well-controlled concentration gradient to determine the optimal concentration of ursolic acid in the wound healing process. The migration of cells according to different concentrations of ursolic acid was achieved easily, quickly, and reliably, and the effect of ursolic acid in promoting cell migration was confirmed. We demonstrated that our system effectively provides an appropriate environment for in vitro wound healing studies and is expected to be an advanced tool and an economically efficient, robust, and reliable platform to study and evaluate new wound healing drugs in vitro.
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