Hang Qi, ShuaiHua Zhang, Jiaxue Liang, Shan He, Yanyan Wang
The blood–brain barrier (BBB) is a structural and functional barrier necessary for brain homeostasis, and it plays an important role in the realization of neural function and in protecting the brain from damage by circulating toxins and pathogens. However, the extremely dense BBB also severely limits the transport of molecules across it, which is a great hindrance to the diagnosis and treatment of central nervous system (CNS) diseases. This paper reports a new method for controllable opening of the BBB, based on the gigahertz acoustic streaming (AS) generated by a bulk acoustic wave resonant device. By adjusting the input power and working distance of the device, AS with tunable flow rate can be generated to disrupt tight junction proteins (TJs) between endothelial cells. The results obtained with this method show that the gigahertz AS promotes the penetration of dextran molecules with different molecular weights across the BBB. This work provides a new platform for studying the mechanical regulation of BBB by fluid shear forces and a new method for improving the efficiency of drug delivery.
{"title":"Controllable blood–brain barrier (BBB) regulation based on gigahertz acoustic streaming","authors":"Hang Qi, ShuaiHua Zhang, Jiaxue Liang, Shan He, Yanyan Wang","doi":"10.1063/10.0014861","DOIUrl":"https://doi.org/10.1063/10.0014861","url":null,"abstract":"The blood–brain barrier (BBB) is a structural and functional barrier necessary for brain homeostasis, and it plays an important role in the realization of neural function and in protecting the brain from damage by circulating toxins and pathogens. However, the extremely dense BBB also severely limits the transport of molecules across it, which is a great hindrance to the diagnosis and treatment of central nervous system (CNS) diseases. This paper reports a new method for controllable opening of the BBB, based on the gigahertz acoustic streaming (AS) generated by a bulk acoustic wave resonant device. By adjusting the input power and working distance of the device, AS with tunable flow rate can be generated to disrupt tight junction proteins (TJs) between endothelial cells. The results obtained with this method show that the gigahertz AS promotes the penetration of dextran molecules with different molecular weights across the BBB. This work provides a new platform for studying the mechanical regulation of BBB by fluid shear forces and a new method for improving the efficiency of drug delivery.","PeriodicalId":35428,"journal":{"name":"Nami Jishu yu Jingmi Gongcheng/Nanotechnology and Precision Engineering","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47887202","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This review considers the fundamental dynamical processes of metal nanoparticles during and after the impact of a femtosecond laser pulse on a nanoparticle, including the absorption of photons. Understanding the sequence of events after photon absorption and their timescales is important for many applications of nanoparticles. Various processes are discussed, starting with optical absorption by electrons, proceeding through the relaxation of the electrons due to electron–electron scattering and electron–phonon coupling, and ending with the dissipation of the nanoparticle energy into the environment. The goal is to consider the timescales, values, and temperature dependences of the electron heat capacity and the electron–phonon coupling parameter that describe these processes and how these dependences affect the electron energy relaxation. Two- and four-temperature models for describing electron–phonon relaxation are discussed. Significant emphasis is paid to the proposed analytical approach to modeling processes during the action of a femtosecond laser pulse on a metal nanoparticle. These consider the temperature dependences of the electron heat capacity and the electron–phonon coupling factor of the metal. The entire process is divided into four stages: (1) the heating of the electron system by a pulse, (2) electron thermalization, (3) electron–phonon energy exchange and the equalization of the temperature of the electrons with the lattice, and (4) cooling of the nanoparticle. There is an appropriate analytical description of each stage. The four-temperature model can estimate the parameters of the laser and nanoparticles needed for applications of femtosecond laser pulses and nanoparticles.
{"title":"Multi-temperature modeling of femtosecond laser pulse on metallic nanoparticles accounting for the temperature dependences of the parameters","authors":"V. Pustovalov","doi":"10.1063/10.0013776","DOIUrl":"https://doi.org/10.1063/10.0013776","url":null,"abstract":"This review considers the fundamental dynamical processes of metal nanoparticles during and after the impact of a femtosecond laser pulse on a nanoparticle, including the absorption of photons. Understanding the sequence of events after photon absorption and their timescales is important for many applications of nanoparticles. Various processes are discussed, starting with optical absorption by electrons, proceeding through the relaxation of the electrons due to electron–electron scattering and electron–phonon coupling, and ending with the dissipation of the nanoparticle energy into the environment. The goal is to consider the timescales, values, and temperature dependences of the electron heat capacity and the electron–phonon coupling parameter that describe these processes and how these dependences affect the electron energy relaxation. Two- and four-temperature models for describing electron–phonon relaxation are discussed. Significant emphasis is paid to the proposed analytical approach to modeling processes during the action of a femtosecond laser pulse on a metal nanoparticle. These consider the temperature dependences of the electron heat capacity and the electron–phonon coupling factor of the metal. The entire process is divided into four stages: (1) the heating of the electron system by a pulse, (2) electron thermalization, (3) electron–phonon energy exchange and the equalization of the temperature of the electrons with the lattice, and (4) cooling of the nanoparticle. There is an appropriate analytical description of each stage. The four-temperature model can estimate the parameters of the laser and nanoparticles needed for applications of femtosecond laser pulses and nanoparticles.","PeriodicalId":35428,"journal":{"name":"Nami Jishu yu Jingmi Gongcheng/Nanotechnology and Precision Engineering","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42449644","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
As the gold-standard method for single-cell analysis, flow cytometry enables high-throughput and multiple-parameter characterization of individual biological cells. This review highlights the demands for clinical flow cytometry in laboratory hematology (e.g., diagnoses of minimal residual disease and various types of leukemia), summarizes state-of-the-art clinical flow cytometers (e.g., FACSLyricTM by Becton Dickinson, DxFLEX by Beckman Coulter), then considers innovative technical improvements in flow cytometry (including quantitative, spectral, and imaging approaches) to address the limitations of clinical flow cytometry in hematology diagnosis. Finally, driven by these clinical demands, future developments in clinical flow cytometry are suggested.
{"title":"Demands and technical developments of clinical flow cytometry with emphasis in quantitative, spectral, and imaging capabilities","authors":"Ting Zhang, M. Gao, Xiao Chen, Chiyuan Gao, Shilun Feng, Deyong Chen, Junbo Wang, Xiaosu Zhao, Jian Chen","doi":"10.1063/10.0015301","DOIUrl":"https://doi.org/10.1063/10.0015301","url":null,"abstract":"As the gold-standard method for single-cell analysis, flow cytometry enables high-throughput and multiple-parameter characterization of individual biological cells. This review highlights the demands for clinical flow cytometry in laboratory hematology (e.g., diagnoses of minimal residual disease and various types of leukemia), summarizes state-of-the-art clinical flow cytometers (e.g., FACSLyricTM by Becton Dickinson, DxFLEX by Beckman Coulter), then considers innovative technical improvements in flow cytometry (including quantitative, spectral, and imaging approaches) to address the limitations of clinical flow cytometry in hematology diagnosis. Finally, driven by these clinical demands, future developments in clinical flow cytometry are suggested.","PeriodicalId":35428,"journal":{"name":"Nami Jishu yu Jingmi Gongcheng/Nanotechnology and Precision Engineering","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46039642","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nanopipette-based sensors are one of the most effective tools for detecting nanoparticles, bioparticles, and biomolecules. Quantitative analysis of nanoparticles with different shapes and electrical charges is achieved through measurement of the blockage currents that occur when particles pass through the nanopore. However, typical nanopipette sensors fabricated using a conventional needle-pulling method have a typical pore-diameter limitation of around 100 nm. Herein, we report a novel conductive hydrogel-composited nanopipette sensor with a tunable inner-pore diameter. This is made by electrodepositing poly(3,4-ethylenedioxythiophene) polystyrene sulfonate onto the surface of a nanopipette with a prefabricated sacrificial copper layer. Because of the presence of copper ions, the conductive polymer can stably adhere to the tip of the nanopipette to form a nanopore; when nanoparticles pass through the conductive nanopore, more distinct blocking events are observed. The size of the nanopore can be changed simply by adjusting the electrodeposition time. In this way, suitable nanopores can be obtained for highly sensitive screening of a series of particles with diameters of the order of tens of nanometers.
{"title":"Conductive polymer hydrogel-coated nanopipette sensor with tunable size","authors":"Lin Li, F. Zhou, Q. Xue","doi":"10.1063/10.0016501","DOIUrl":"https://doi.org/10.1063/10.0016501","url":null,"abstract":"Nanopipette-based sensors are one of the most effective tools for detecting nanoparticles, bioparticles, and biomolecules. Quantitative analysis of nanoparticles with different shapes and electrical charges is achieved through measurement of the blockage currents that occur when particles pass through the nanopore. However, typical nanopipette sensors fabricated using a conventional needle-pulling method have a typical pore-diameter limitation of around 100 nm. Herein, we report a novel conductive hydrogel-composited nanopipette sensor with a tunable inner-pore diameter. This is made by electrodepositing poly(3,4-ethylenedioxythiophene) polystyrene sulfonate onto the surface of a nanopipette with a prefabricated sacrificial copper layer. Because of the presence of copper ions, the conductive polymer can stably adhere to the tip of the nanopipette to form a nanopore; when nanoparticles pass through the conductive nanopore, more distinct blocking events are observed. The size of the nanopore can be changed simply by adjusting the electrodeposition time. In this way, suitable nanopores can be obtained for highly sensitive screening of a series of particles with diameters of the order of tens of nanometers.","PeriodicalId":35428,"journal":{"name":"Nami Jishu yu Jingmi Gongcheng/Nanotechnology and Precision Engineering","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45320932","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Superhydrophilic–superhydrophobic patterned surfaces constitute a branch of surface chemistry involving the two extreme states of superhydrophilicity and superhydrophobicity combined on the same surface in precise patterns. Such surfaces have many advantages, including controllable wettability, enrichment ability, accessibility, and the ability to manipulate and pattern water droplets, and they offer new functionalities and possibilities for a wide variety of emerging applications, such as microarrays, biomedical assays, microfluidics, and environmental protection. This review presents the basic theory, simplified fabrication, and emerging applications of superhydrophilic–superhydrophobic patterned surfaces. First, the fundamental theories of wettability that explain the spreading of a droplet on a solid surface are described. Then, the fabrication methods for preparing superhydrophilic–superhydrophobic patterned surfaces are introduced, and the emerging applications of such surfaces that are currently being explored are highlighted. Finally, the remaining challenges of constructing such surfaces and future applications that would benefit from their use are discussed.
{"title":"Superhydrophilic–superhydrophobic patterned surfaces: From simplified fabrication to emerging applications","authors":"Hao Chen, Xiaoping Li, Dachao Li","doi":"10.1063/10.0013222","DOIUrl":"https://doi.org/10.1063/10.0013222","url":null,"abstract":"Superhydrophilic–superhydrophobic patterned surfaces constitute a branch of surface chemistry involving the two extreme states of superhydrophilicity and superhydrophobicity combined on the same surface in precise patterns. Such surfaces have many advantages, including controllable wettability, enrichment ability, accessibility, and the ability to manipulate and pattern water droplets, and they offer new functionalities and possibilities for a wide variety of emerging applications, such as microarrays, biomedical assays, microfluidics, and environmental protection. This review presents the basic theory, simplified fabrication, and emerging applications of superhydrophilic–superhydrophobic patterned surfaces. First, the fundamental theories of wettability that explain the spreading of a droplet on a solid surface are described. Then, the fabrication methods for preparing superhydrophilic–superhydrophobic patterned surfaces are introduced, and the emerging applications of such surfaces that are currently being explored are highlighted. Finally, the remaining challenges of constructing such surfaces and future applications that would benefit from their use are discussed.","PeriodicalId":35428,"journal":{"name":"Nami Jishu yu Jingmi Gongcheng/Nanotechnology and Precision Engineering","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2022-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47937600","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Interdigitated transducers (IDTs) were originally designed as delay lines for radars. Half a century later, they have found new life as actuators for microfluidic systems. By generating strong acoustic fields, they trigger nonlinear effects that enable pumping and mixing of fluids, and moving particles without contact. However, the transition from signal processing to actuators comes with a range of challenges concerning power density and spatial resolution that have spurred exciting developments in solid-state acoustics and especially in IDT design. Assuming some familiarity with acoustofluidics, this paper aims to provide a tutorial for IDT design and characterization for the purpose of acoustofluidic actuation. It is targeted at a diverse audience of researchers in various fields, including fluid mechanics, acoustics, and microelectronics.
{"title":"Design of interdigitated transducers for acoustofluidic applications","authors":"Shuren Song, Qi Wang, Jia Zhou, A. Riaud","doi":"10.1063/10.0013405","DOIUrl":"https://doi.org/10.1063/10.0013405","url":null,"abstract":"Interdigitated transducers (IDTs) were originally designed as delay lines for radars. Half a century later, they have found new life as actuators for microfluidic systems. By generating strong acoustic fields, they trigger nonlinear effects that enable pumping and mixing of fluids, and moving particles without contact. However, the transition from signal processing to actuators comes with a range of challenges concerning power density and spatial resolution that have spurred exciting developments in solid-state acoustics and especially in IDT design. Assuming some familiarity with acoustofluidics, this paper aims to provide a tutorial for IDT design and characterization for the purpose of acoustofluidic actuation. It is targeted at a diverse audience of researchers in various fields, including fluid mechanics, acoustics, and microelectronics.","PeriodicalId":35428,"journal":{"name":"Nami Jishu yu Jingmi Gongcheng/Nanotechnology and Precision Engineering","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2022-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44141276","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jethro Vernon, P. Canyelles-Pericas, H. Torun, R. Binns, Wai Pang Ng, Qiang Wu, Y. Fu
Apnoea, a major sleep disorder, affects many adults and causes several issues, such as fatigue, high blood pressure, liver conditions, increased risk of type II diabetes, and heart problems. Therefore, advanced monitoring and diagnosing tools of apnoea disorders are needed to facilitate better treatment, with advantages such as accuracy, comfort of use, cost effectiveness, and embedded computation capabilities to recognise, store, process, and transmit time series data. In this work we present an adaptation of our apnoea-Pi open-source surface acoustic wave (SAW) platform (Apnoea-Pi) to monitor and recognise apnoea in patients. The platform is based on a thin-film SAW device using bimorph ZnO and Al structures, including those fabricated as Al foils or plates, to achieve breath tracking based on humidity and temperature changes. We applied open-source electronics and provided embedded computing characteristics for signal processing, data recognition, storage, and transmission of breath signals. We show that the thin-film SAW device out-performed standard and off-the-shelf capacitive electronic sensors in terms of their response and accuracy for human breath-tracking purposes. This in combination with embedded electronics makes a suitable platform for human breath monitoring and sleep disorder recognition.
{"title":"Breath monitoring, sleep disorder detection, and tracking using thin-film acoustic waves and open-source electronics","authors":"Jethro Vernon, P. Canyelles-Pericas, H. Torun, R. Binns, Wai Pang Ng, Qiang Wu, Y. Fu","doi":"10.1063/10.0013471","DOIUrl":"https://doi.org/10.1063/10.0013471","url":null,"abstract":"Apnoea, a major sleep disorder, affects many adults and causes several issues, such as fatigue, high blood pressure, liver conditions, increased risk of type II diabetes, and heart problems. Therefore, advanced monitoring and diagnosing tools of apnoea disorders are needed to facilitate better treatment, with advantages such as accuracy, comfort of use, cost effectiveness, and embedded computation capabilities to recognise, store, process, and transmit time series data. In this work we present an adaptation of our apnoea-Pi open-source surface acoustic wave (SAW) platform (Apnoea-Pi) to monitor and recognise apnoea in patients. The platform is based on a thin-film SAW device using bimorph ZnO and Al structures, including those fabricated as Al foils or plates, to achieve breath tracking based on humidity and temperature changes. We applied open-source electronics and provided embedded computing characteristics for signal processing, data recognition, storage, and transmission of breath signals. We show that the thin-film SAW device out-performed standard and off-the-shelf capacitive electronic sensors in terms of their response and accuracy for human breath-tracking purposes. This in combination with embedded electronics makes a suitable platform for human breath monitoring and sleep disorder recognition.","PeriodicalId":35428,"journal":{"name":"Nami Jishu yu Jingmi Gongcheng/Nanotechnology and Precision Engineering","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2022-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45054302","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
One of the key requirements for MEMS speakers is to increase the sound pressure level (SPL) while keeping the size as small as possible. In this paper we present a MEMS speaker based on piezoelectric bimorph cantilevers that produces a higher SPL than conventional unimorph cantilever speakers. The active diaphragm size is 1.4 × 1.4 mm2. The bimorph cantilevers are connected in parallel to make full use of the actuation voltage. At 1 kHz, the measured SPL reached 73 dB and the peak SPL reached 102 dB at the resonance frequency of 10 kHz in a 711 ear simulator under a driving voltage of 10 Vrms. The total harmonic distortion of the MEMS speaker was less than 3% in the range from 100 Hz to 20 kHz. Although the absolute SPL was not the highest, this work provides a better SPL for all piezoelectric MEMS speakers.
{"title":"Piezoelectric bimorph MEMS speakers","authors":"Yiming Lang, Chengze Liu, Ahmed Fawzy, Chen Sun, Shaobo Gong, Menglun Zhang","doi":"10.1063/10.0013406","DOIUrl":"https://doi.org/10.1063/10.0013406","url":null,"abstract":"One of the key requirements for MEMS speakers is to increase the sound pressure level (SPL) while keeping the size as small as possible. In this paper we present a MEMS speaker based on piezoelectric bimorph cantilevers that produces a higher SPL than conventional unimorph cantilever speakers. The active diaphragm size is 1.4 × 1.4 mm2. The bimorph cantilevers are connected in parallel to make full use of the actuation voltage. At 1 kHz, the measured SPL reached 73 dB and the peak SPL reached 102 dB at the resonance frequency of 10 kHz in a 711 ear simulator under a driving voltage of 10 Vrms. The total harmonic distortion of the MEMS speaker was less than 3% in the range from 100 Hz to 20 kHz. Although the absolute SPL was not the highest, this work provides a better SPL for all piezoelectric MEMS speakers.","PeriodicalId":35428,"journal":{"name":"Nami Jishu yu Jingmi Gongcheng/Nanotechnology and Precision Engineering","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2022-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42500642","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Acoustofluidic technology combines acoustic and microfluidic technologies to realize particle manipulation in microchannels driven by acoustic waves, and the acoustic radiation force (ARF) with boundaries is important for particle manipulation in an acoustofluidic device. In the work reported here, the ARF on a free cylinder immersed in a viscous fluid with an incident plane wave between two impedance boundaries is derived analytically and calculated numerically. The influence of multiple scattering between the particle and the impedance boundaries is described by means of image theory, the finite-series method, and the translational addition theorem, and multiple scattering is included partly in image theory. The ARF on a free rigid cylinder in a viscous fluid is analyzed by numerical calculation, with consideration given to the effects of the distances from cylinder edge to boundaries, fluid viscosity, cylinder size, and boundary reflectivity. The results show that the interaction between the two boundaries and the cylinder makes the ARF change more violently with different frequencies, while increasing the viscosity can reduce the amplitude of the ARF in boundary space. This study provides a theoretical basis for particle manipulation by the ARF in acoustofluidics.
{"title":"Acoustic radiation force on a rigid cylinder between two impedance boundaries in a viscous fluid","authors":"Xinlei Liu, Zhaoyu Deng, Li Ma, Xiaozhou Liu","doi":"10.1063/10.0013562","DOIUrl":"https://doi.org/10.1063/10.0013562","url":null,"abstract":"Acoustofluidic technology combines acoustic and microfluidic technologies to realize particle manipulation in microchannels driven by acoustic waves, and the acoustic radiation force (ARF) with boundaries is important for particle manipulation in an acoustofluidic device. In the work reported here, the ARF on a free cylinder immersed in a viscous fluid with an incident plane wave between two impedance boundaries is derived analytically and calculated numerically. The influence of multiple scattering between the particle and the impedance boundaries is described by means of image theory, the finite-series method, and the translational addition theorem, and multiple scattering is included partly in image theory. The ARF on a free rigid cylinder in a viscous fluid is analyzed by numerical calculation, with consideration given to the effects of the distances from cylinder edge to boundaries, fluid viscosity, cylinder size, and boundary reflectivity. The results show that the interaction between the two boundaries and the cylinder makes the ARF change more violently with different frequencies, while increasing the viscosity can reduce the amplitude of the ARF in boundary space. This study provides a theoretical basis for particle manipulation by the ARF in acoustofluidics.","PeriodicalId":35428,"journal":{"name":"Nami Jishu yu Jingmi Gongcheng/Nanotechnology and Precision Engineering","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2022-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43227004","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Cerium–lanthanum alloys are the main component of nickel–metal hydride batteries, and they are thus an important material in the green-energy industry. However, these alloys have very strong chemical activity, and their surfaces are easily oxidized, leading to great difficulties in their application. To improve the corrosion resistance of cerium–lanthanum alloys, it is necessary to obtain a nanoscale surface with low roughness. However, these alloys can easily succumb to spontaneous combustion during machining. Currently, to inhibit the occurrence of fire, machining of this alloy in ambient air needs to be conducted at very low cutting speeds while spraying the workpiece with a large amount of cutting fluid. However, this is inefficient, and only a very limited range of parameters can be optimized at low cutting speeds; this restricts the optimization of other cutting parameters. To achieve ultraprecision machining of cerium–lanthanum alloys, in this work, an auxiliary machining device was developed, and its effectiveness was verified. The results show that the developed device can improve the cutting speed and obtain a machined surface with low roughness. The device can also improve the machining efficiency and completely prevent the occurrence of spontaneous combustion. It was found that the formation of a build-up of swarf on the cutting tool is eliminated with high-speed cutting, and the surface roughness (Sa) can reach 5.64 nm within the selected parameters. Finally, the oxidation processes of the cerium–lanthanum alloy and its swarf were studied, and the process of the generation of oxidative products in the swarf was elucidated. The results revealed that most of the intermediate oxidative products in the swarf were Ce3+, there were major oxygen vacancies in the swarf, and the final oxidative product was Ce4+.
{"title":"Ultra-precision machining of cerium-lanthanum alloy with atmosphere control in an auxiliary device","authors":"Chenyu Zhao, Sheng-Chang Wu, M. Lai","doi":"10.1063/10.0013777","DOIUrl":"https://doi.org/10.1063/10.0013777","url":null,"abstract":"Cerium–lanthanum alloys are the main component of nickel–metal hydride batteries, and they are thus an important material in the green-energy industry. However, these alloys have very strong chemical activity, and their surfaces are easily oxidized, leading to great difficulties in their application. To improve the corrosion resistance of cerium–lanthanum alloys, it is necessary to obtain a nanoscale surface with low roughness. However, these alloys can easily succumb to spontaneous combustion during machining. Currently, to inhibit the occurrence of fire, machining of this alloy in ambient air needs to be conducted at very low cutting speeds while spraying the workpiece with a large amount of cutting fluid. However, this is inefficient, and only a very limited range of parameters can be optimized at low cutting speeds; this restricts the optimization of other cutting parameters. To achieve ultraprecision machining of cerium–lanthanum alloys, in this work, an auxiliary machining device was developed, and its effectiveness was verified. The results show that the developed device can improve the cutting speed and obtain a machined surface with low roughness. The device can also improve the machining efficiency and completely prevent the occurrence of spontaneous combustion. It was found that the formation of a build-up of swarf on the cutting tool is eliminated with high-speed cutting, and the surface roughness (Sa) can reach 5.64 nm within the selected parameters. Finally, the oxidation processes of the cerium–lanthanum alloy and its swarf were studied, and the process of the generation of oxidative products in the swarf was elucidated. The results revealed that most of the intermediate oxidative products in the swarf were Ce3+, there were major oxygen vacancies in the swarf, and the final oxidative product was Ce4+.","PeriodicalId":35428,"journal":{"name":"Nami Jishu yu Jingmi Gongcheng/Nanotechnology and Precision Engineering","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2022-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46319391","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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